1 Documentation and download available at https://www.FreeRTOS.org/
3 Changes between FreeRTOS V11.0.1 and FreeRTOS V11.1.0 released April 22, 2024
5 + Add ARMv7-R port with Memory Protection Unit (MPU) support.
6 + Add Memory Protection Unit (MPU) support to the Cortex-M0 port.
7 + Add stream batching buffer. A stream batching buffer differs from a stream
8 buffer when a task reads from a non-empty buffer:
9 - The task reading from a non-empty stream buffer returns immediately
10 regardless of the amount of data in the buffer.
11 - The task reading from a non-empty steam batching buffer blocks until the
12 amount of data in the buffer exceeds the trigger level or the block time
14 We thank @cperkulator for their contribution.
15 + Add the ability to change task notification index for stream buffers. We
16 thank @glemco for their contribution.
17 + Add xStreamBufferResetFromISR and xMessageBufferResetFromISR APIs to reset
18 stream buffer and message buffer from an Interrupt Service Routine (ISR).
19 We thank @HagaiMoshe for their contribution.
20 + Update all the FreeRTOS APIs to use configSTACK_DEPTH_TYPE for stack type.
21 We thank @feilipu for their contribution.
22 + Update vTaskEndScheduler to delete the timer and idle tasks,
23 once the scheduler is stopped.
24 + Make xTaskGetCurrentTaskHandleForCore() available to the single core
25 scheduler. We thank @Dazza0 for their contribution.
26 + Update uxTaskGetSystemState to not use the pxIndex member of the List_t
27 structure while iterating ready tasks list. The reason is that pxIndex
28 member must only used to select next ready task to run. We thank
29 @gemarcano for their inputs.
30 + Add a config option to the FreeRTOS SMP Kernel to set the default core
31 affinity mask for tasks created without an affinity mask. We thank @go2sh
32 for their contribution.
33 + Add configUSE_EVENT_GROUPS and configUSE_STREAM_BUFFERS configuration
34 constants to control the inclusion of event group and stream buffer
36 + Code changes to comply with MISRA C 2012.
37 + Add 64-bit support to the FreeRTOS Windows Simulator port. We thank @watsk
38 and @josesimoes for their contributions.
39 + Add support for 64-bit Microblaze processor to the MicroblazeV9 port. We
40 thank @mubinsyed for their contribution.
41 + Add support for MSP430 Embedded Application Binary Interface (EABI) to
42 the MSP430F449 port to make it work with both MSP430 GCC and MSPGCC
43 compilers. We thank @Forty-Bot for their contribution.
44 + Update xPortIsAuthorizedToAccessBuffer() on FreeRTOS ports with MPU
45 support to grant an unprivileged task access to all the memory before the
47 + Update the POSIX port to pass the FreeRTOS task name to pthread for
48 readable output in debuggers. We thank @Mixaill for their contribution.
49 + Update the POSIX port to ignore the user specified stack memory and only
50 pass the stack size to the pthread API to avoid errors caused when stack size
51 is smaller than the minimum. We thank @cmorgnaBE for their
53 + Update the POSIX port to use a timer thread for tick interrupts instead of
54 POSIX timers to address issues with signal handling in non-FreeRTOS
55 pthreads. We thank @cmorgnaBE for their contribution.
56 + Update ARM_TFM port to support TF-Mv2.0.0 release of trusted-firmware-m.
57 We thanks @urutva for their contribution.
58 + Remove redundant constant pools in ARMv8 ports. We thank @urutva for their
60 + Add APIs to reset the internal state of kernel modules. These APIs are
61 primarily intended to be used in the testing frameworks that restart the
63 + Use kernel provided implementations of vApplicationGetIdleTaskMemory() and
64 vApplicationGetTimerTaskMemory() in the RP2040 port. We thank @dpslwk for
66 + Fix atomic enter/exit critical section macro definitions in atomic.h for
67 ports that support nested interrupts. We thank @sebunger for their
69 + Fix compiler warnings in the MSP430F449 port when compiled with the
70 MSP430 GCC compiler. We thank @Forty-Bot for their contribution.
71 + Update the scheduler suspension usage in ulTaskGenericNotifyTake and
72 xTaskGenericNotifyWait() to enhance code readability. We thank @Dazza0 for
74 + Add support for latest version of MPU wrappers( mpu_wrappers_v2) in CMake.
75 We thank @IsaacDynamo for their contribution.
76 + Update CMake support to create only one static library containing both the
77 kernel common code and the kernel port code. We thank @barnatahmed for
80 Changes between FreeRTOS V11.0.0 and FreeRTOS V11.0.1 released December 21, 2023
82 + Updated the SBOM file.
84 Changes between FreeRTOS V10.6.2 and FreeRTOS V11.0.0 released December 18, 2023
86 + SMP merged into the mainline: While FreeRTOS introduced Asymmetric
87 Multiprocessing (AMP) support in 2017, FreeRTOS Version 11.0.0 is the
88 first to merge Symmetric Multiprocessing (SMP) support into the mainline
89 release. SMP enables one instance of the FreeRTOS Kernel to schedule tasks
90 across multiple identical processor cores. We thank Mike Bruno and Jerry
91 McCarthy of XMOS and, Darian Liang, Sudeep Mohanty and Zim Kalinowski of
92 Espressif Systems for their contributions.
93 + Switch MISRA compliance checking from PC Lint to Coverity, and update from
94 MISRA C:2004 to MISRA C:2012.
95 + Add a template FreeRTOSConfig.h, inclusive of an abbreviated explanation of
96 each configuration item. Application writers can use this template as a
97 starting point to create the FreeRTOSConfig.h file for their application.
98 + Add a template FreeRTOS port which can be used as a starting point for
99 developing a new FreeRTOS port.
100 + Add bounds checking and obfuscation to internal heap block pointers in
101 heap_4.c and heap_5.c to help catch pointer corruptions. The application can
102 enable these checks by setting configENABLE_HEAP_PROTECTOR to 1 in their
103 FreeRTOSConfig.h. We thank @oliverlavery for their contribution.
104 + Update vTaskList and vTaskGetRunTimeStats APIs to replace the use of sprintf
106 + Add trace macros to ports that enable tracing the interaction of ISRs with
107 scheduler events. We thank @conara for their contribution.
108 + Add trace macros that enable tracing of entering and exiting all APIs. We
109 thank @Techcore123 for their contribution.
110 + Add uxTaskBasePriorityGet and uxTaskBasePriorityGetFromISR APIs to get the
111 base priority of a task. The base priority of a task is the priority that
112 was last assigned to the task - which due to priority inheritance, may not
113 be the current priority of the task.
114 + Add pdTICKS_TO_MS macro to convert time in FreeRTOS ticks to time in
115 milliseconds. We thank @Dazza0 for their contribution.
116 + Add default implementations of vApplicationGetIdleTaskMemory and
117 vApplicationGetTimerTaskMemory. The application can enable these default
118 implementations by setting configKERNEL_PROVIDED_STATIC_MEMORY to 1 in their
119 FreeRTOSConfig.h. We thank @mdnr-g for their contribution.
120 + Update vTaskGetInfo to include start and end of the stack whenever both
121 values are available. We thank @vinceburns for their contribution.
122 + Prevent tasks waiting for a notification from being resumed by calls to
123 vTaskResume or vTaskResumeFromISR. We thank @Moral-Hao for their
125 + Add asserts to validate that the application has correctly installed
126 FreeRTOS handlers for PendSV and SVCall interrupts on Cortex-M devices.
127 We thank @jefftenney for their contribution.
128 + Rename ARM_CA53_64_BIT and ARM_CA53_64_BIT_SRE ports to Arm_AARCH64 and
129 Arm_AARCH64_SRE respectively as these ports are applicable to all AArch64
130 architecture. We thank @urutva for their contribution.
131 + Add CMake support to allow the application writer to select the RISC-V
132 chip extension. We thank @JoeBenczarski for their contribution.
133 + Add CMake support to allow the application writer to build an application
134 with static allocation only. We thank @conara for their contribution.
135 + Make taskYIELD available to unprivileged tasks for ARMv8-M ports.
136 + Update Cortex-M23 ports to not use PSPLIM_NS. We thank @urutva for their
138 + Update the SysTick setup code for ARMv8-M ports to first configure the clock
139 source and then enable SysTick. This is needed to address a bug in QEMU
140 versions older than 7.0.0, which causes an emulation error if SysTick is
141 enabled without first selecting a valid clock source. We thank @jefftenney
142 for their contribution.
143 + Add the port-optimized task selection algorithm optionally available for
144 ARMv7-M ports to the ARMv8-M ports. We thank @jefftenney for their
146 + Improve the speed of pvPortMalloc in heap_4.c and heap_5.c by removing
147 unnecessary steps while splitting a large memory block into two. We thank
148 @Moral-Hao for their contribution.
149 + Shorten the critical section in pvPortMalloc in heap_2.c, heap_4.c and
150 heap_5.c by moving the size calculation out of the critical section. We thank
151 @Moral-Hao for their contribution.
152 + Update xTaskNotifyWait and ulTaskNotifyTake to remove the non-deterministic
153 operation of traversing a linked link from a critical section. We thank
154 @karver8 for their contribution.
155 + Fix stack end and stack size computation in POSIX port to meet the stack
156 alignment requirements on MacOS. We thank @tegimeki for their contribution.
157 + Update the vTaskPrioritySet implementation to use the new priority when the
158 task has inherited priority from a mutex it is holding, and the new priority
159 is bigger than the inherited priority. We thank @Moral-Hao for their
161 + Add stack alignment adjustment if stack grows upwards. We thank @ivq for
163 + Fix pxTopOfStack calculation in configINIT_TLS_BLOCK when picolib C is
164 selected as the C library implementation to ensure that
165 pxPortInitialiseStack does not overwrite the data in the TLS block portion
166 of the stack. We thank @bebebib-rs for their contribution.
167 + Fix vPortEndScheduler() for the MSVC port so that the function
168 prvProcessSimulatedInterrupts is not stuck in an infinite loop when the
169 scheduler is stopped. We thank @Ju1He1 for their contribution.
170 + Add the Pull Request (PR) Process explaining the stages a PR goes through.
172 Changes between FreeRTOS V10.6.1 and FreeRTOS V10.6.2 released November 29, 2023
174 + Add the following improvements to the new MPU wrapper (mpu_wrappers_v2.c)
175 introduced in version 10.6.0:
176 - Introduce Access Control List (ACL) feature to allow the application
177 writer to control an unprivileged task’s access to kernel objects.
178 - Update the system call entry mechanism to only require one Supervisor
179 Call (SVC) instruction.
180 - Wrap parameters for system calls with more than four parameters in a
181 struct to avoid special handling during system call entry.
182 - Fix 2 possible integer overflows.
183 - Convert some asserts to run time parameter checks.
185 Changes between FreeRTOS V10.6.0 and FreeRTOS V10.6.1 released August 17, 2023
187 + Add runtime parameter checks to functions in mpu_wrappers_v2.c file.
188 The same checks are already performed in API implementations using
190 We thank the following people for their inputs in these changes:
191 - Lan Luo, Zixia Liu of School of Computer Science and Technology,
192 Anhui University of Technology, China.
193 - Xinwen Fu of Department of Computer Science, University of
194 Massachusetts Lowell, USA.
195 - Xinhui Shao, Yumeng Wei, Huaiyu Yan, Zhen Ling of School of
196 Computer Science and Engineering, Southeast University, China.
198 Changes between FreeRTOS V10.5.1 and FreeRTOS 10.6.0 released July 13, 2023
200 + Add a new MPU wrapper that places additional restrictions on unprivileged
201 tasks. The following is the list of changes introduced with the new MPU
204 1. Opaque and indirectly verifiable integers for kernel object handles:
205 All the kernel object handles (for example, queue handles) are now
206 opaque integers. Previously object handles were raw pointers.
207 2. Save the task context in Task Control Block (TCB): When a task is
208 swapped out by the scheduler, the task's context is now saved in its
209 TCB. Previously the task's context was saved on its stack.
210 3. Execute system calls on a separate privileged only stack: FreeRTOS
211 system calls, which execute with elevated privilege, now use a
212 separate privileged only stack. Previously system calls used the
213 calling task's stack. The application writer can control the size of
214 the system call stack using new configSYSTEM_CALL_STACK_SIZE config
216 4. Memory bounds checks: FreeRTOS system calls which accept a pointer
217 and de-reference it, now verify that the calling task has required
218 permissions to access the memory location referenced by the pointer.
219 5. System calls restrictions: The following system calls are no longer
220 available to unprivileged tasks:
223 - xQueueCreateMutexStatic
224 - xQueueCreateCountingSemaphore
225 - xQueueCreateCountingSemaphoreStatic
226 - xQueueGenericCreate
227 - xQueueGenericCreateStatic
229 - xQueueRemoveFromSet
238 - xTaskCallApplicationTaskHook
240 - vTaskGetRunTimeStats
243 - xEventGroupCreateStatic
245 - xStreamBufferGenericCreate
246 - xStreamBufferGenericCreateStatic
247 - vStreamBufferDelete
249 Also, an unprivileged task can no longer use vTaskSuspend to suspend
250 any task other than itself.
252 We thank the following people for their inputs in these enhancements:
253 - David Reiss of Meta Platforms, Inc.
254 - Lan Luo, Xinhui Shao, Yumeng Wei, Zixia Liu, Huaiyu Yan and Zhen Ling
255 of School of Computer Science and Engineering, Southeast University,
257 - Xinwen Fu of Department of Computer Science, University of
258 Massachusetts Lowell, USA.
259 - Yueqi Chen, Zicheng Wang, Minghao Lin, Jiahe Wang of University of
260 Colorado Boulder, USA.
261 + Add Cortex-M35P port. Contributed by @urutva.
262 + Add embedded extension (RV32E) support to the IAR RISC-V port.
263 + Add ulTaskGetRunTimeCounter and ulTaskGetRunTimePercent APIs. Contributed by
265 + Add APIs to get the application supplied buffers from statically
266 created kernel objects. The following new APIs are added:
267 - xTaskGetStaticBuffers
268 - xQueueGetStaticBuffers
269 - xQueueGenericGetStaticBuffers
270 - xSemaphoreGetStaticBuffer
271 - xEventGroupGetStaticBuffer
272 - xStreamBufferGetStaticBuffers
273 - xMessageBufferGetStaticBuffers
274 These APIs enable the application writer to obtain static buffers from
275 the kernel object and free/reuse them at the time of deletion. Earlier
276 the application writer had to maintain the association of static buffers
277 and the kernel object in the application. Contributed by @Dazza0.
278 + Add Thread Local Storage (TLS) support using picolibc function. Contributed
280 + Add configTICK_TYPE_WIDTH_IN_BITS to configure TickType_t data type. As a result,
281 the number of bits in an event group also increases with big data type. Contributed
283 + Update eTaskGetState and uxTaskGetSystemState to return eReady for pending ready
284 tasks. Contributed by @Dazza0.
285 + Update heap_4 and heap_5 to add padding only if the resulting block is not
287 + Fix the scheduler logic in a couple of places to not preempt a task when an
288 equal priority task becomes ready.
289 + Add macros used in FreeRTOS-Plus libraries. Contributed by @Holden.
290 + Fix clang compiler warnings. Contributed by @phelter.
291 + Add assertions to ARMv8-M ports to detect when FreeRTOS APIs are called from
292 interrupts with priority higher than the configMAX_SYSCALL_INTERRUPT_PRIORITY.
293 Contributed by @urutva.
294 + Add xPortIsInsideInterrupt API to ARM_CM0 ports.
295 + Fix build warning in MSP430X port when large data model is used.
296 + Add the ability to use Cortex-R5 port on the parts without FPU.
297 + Fix build warning in heap implementations on PIC24/dsPIC.
298 + Update interrupt priority asserts for Cortex-M ports so that these do not fire
299 on QEMU which does not implement PRIO bits.
300 + Update ARMv7-M ports to ensure that kernel interrupts run at the lowest priority.
301 configKERNEL_INTERRUPT_PRIORITY is now obsolete for ARMv7-M ports and brings
302 these ports inline with the newer ARMv8-M ports. Contributed by @chrisnc.
303 + Fix build issue in POSIX GCC port on Windows Subsystem for Linux (WSL). Contributed
305 + Add portMEMORY_BARRIER to Microblaze port. Contributed by @bbain.
306 + Add portPOINTER_SIZE_TYPE definition for ATmega port. Contributed by @jputcu.
307 + Multiple improvements in the CMake support. Contributed by @phelte and @cookpate.
309 Changes between FreeRTOS V10.5.0 and FreeRTOS V10.5.1 released November 16 2022
310 + Updated the kernel version in manifest and SBOM
312 Changes between FreeRTOS V10.4.6 and FreeRTOS V10.5.0 released September 16 2022
314 + ARMv7-M and ARMv8-M MPU ports: It was possible for a third party that
315 already independently gained the ability to execute injected code to
316 read from or write to arbitrary addresses by passing a negative argument
317 as the xIndex parameter to pvTaskGetThreadLocalStoragePointer() or
318 vTaskSetThreadLocalStoragePointer respectively. A check has been added to
319 ensure that passing a negative argument as the xIndex parameter does not
320 cause arbitrary read or write.
321 We thank Certibit Consulting, LLC for reporting this issue.
322 + ARMv7-M and ARMv8-M MPU ports: It was possible for an unprivileged task
323 to invoke any function with privilege by passing it as a parameter to
324 MPU_xTaskCreate, MPU_xTaskCreateStatic, MPU_xTimerCreate,
325 MPU_xTimerCreateStatic, or MPU_xTimerPendFunctionCall. MPU_xTaskCreate
326 and MPU_xTaskCreateStatic have been updated to only allow creation of
327 unprivileged tasks. MPU_xTimerCreate, MPU_xTimerCreateStatic and
328 MPU_xTimerPendFunctionCall APIs have been removed.
329 We thank Huazhong University of Science and Technology for reporting
331 + ARMv7-M and ARMv8-M MPU ports: It was possible for a third party that
332 already independently gained the ability to execute injected code to
333 achieve further privilege escalation by branching directly inside a
334 FreeRTOS MPU API wrapper function with a manually crafted stack frame.
335 The local stack variable `xRunningPrivileged` has been removed so that
336 a manually crafted stack frame cannot be used for privilege escalation
337 by branching directly inside a FreeRTOS MPU API wrapper.
338 We thank Certibit Consulting, LLC, Huazhong University of Science and
339 Technology and the SecLab team at Northeastern University for reporting
341 + ARMv7-M MPU ports: It was possible to configure overlapping memory
342 protection unit (MPU) regions such that an unprivileged task could access
343 privileged data. The kernel now uses highest numbered MPU regions for
344 kernel protections to prevent such MPU configurations.
345 We thank the SecLab team at Northeastern University for reporting this
347 + Add support for ARM Cortex-M55.
348 + Add support for ARM Cortex-M85. Contributed by @gbrtth.
349 + Add vectored mode interrupt support to the RISC-V port.
350 + Add support for RV32E extension (Embedded Profile) in RISC-V GCC port.
351 Contributed by @Limoto.
353 - Add a check to heap_2 to track if a memory block is allocated to
354 the application or not. The MSB of the size field is used for this
355 purpose. The same check already exists in heap_4 and heap_5. This
356 check prevents double free errors.
357 - Add a new flag configHEAP_CLEAR_MEMORY_ON_FREE to heap_2, heap_4
358 and heap_5. If the flag is set in FreeRTOSConfig.h then memory freed using
359 vPortFree() is automatically cleared to zero.
360 - Add a new API pvPortCalloc to heap_2, heap_4 and heap_5 which has the same
361 signature as the standard library calloc function.
362 - Update the pointer types to portPOINTER_SIZE_TYPE. Contributed by
364 + Add the ability to override send and receive completed callbacks for each
365 instance of a stream buffer or message buffer. Earlier there could be
366 one send and one receive callback for all instances of stream and message
367 buffers. Having separate callbacks per instance allows different message
368 and stream buffers to be used differently - for example, some for inter core
369 communication and others for same core communication.
370 The feature can be controlled by setting the configuration option
371 configUSE_SB_COMPLETED_CALLBACK in FreeRTOSConfig.h. When the option is set to 1,
372 APIs xStreamBufferCreateWithCallback() or xStreamBufferCreateStaticWithCallback()
373 (and likewise APIs for message buffer) can be used to create a stream buffer
374 or message buffer instance with application provided callback overrides. When
375 the option is set to 0, then the default callbacks as defined by
376 sbSEND_COMPLETED() and sbRECEIVE_COMPLETED() macros are invoked. To maintain
377 backwards compatibility, configUSE_SB_COMPLETED_CALLBACK defaults to 0. The
378 functionality is currently not supported for MPU enabled ports.
379 + Generalize the FreeRTOS's Thread Local Storage (TLS) support so that it
380 is not tied to newlib and can be used with other c-runtime libraries also.
381 The default behavior for newlib support is kept same for backward
383 + Add support to build and link FreeRTOS using CMake build system. Contributed
385 + Add support to generate Software Bill of Materials (SBOM) for every release.
386 + Add support for 16 MPU regions to the GCC Cortex-M33 ports.
387 + Add ARM Cortex-M7 r0p0/r0p1 Errata 837070 workaround to ARM CM4 MPU ports.
388 The application writer needs to define configENABLE_ERRATA_837070_WORKAROUND
389 when using CM4 MPU ports on a Cortex-M7 r0p0/r0p1 core.
390 + Add configSYSTICK_CLOCK_HZ to Cortex-M0 ports. This is needed to support
391 the case when the SysTick timer is not clocked from the same source as the CPU.
392 + Add hardware stack protection support to MicroBlazeV9 port. This ensures that
393 the CPU immediately raises Stack Protection Violation exception as soon as any
394 task violates its stack limits. Contributed by @uecasm.
395 + Introduce the configUSE_MINI_LIST_ITEM configuration option. When this
396 option is set to 1, ListItem_t and MiniLitItem_t remain separate types.
397 However, when configUSE_MINI_LIST_ITEM == 0, MiniLitItem_t and ListItem_t
398 are both typedefs of the same struct xLIST_ITEM. This addresses some issues
399 observed when strict-aliasing and link time optimization are enabled.
400 To maintain backwards compatibility, configUSE_MINI_LIST_ITEM defaults to 1.
401 + Simplify prvInitialiseNewTask to memset newly allocated TCB structures
402 to zero, and remove code that set individual structure members to zero.
403 + Add prototype for prvPortYieldFromISR to the POSIX port so that it builds
404 without any warning with -Wmissing-prototypes compiler option.
405 + Add top of stack and end of stack to the task info report obtained using
406 vTaskGetInfo(). Contributed by @shreyasbharath.
407 + Add a cap to the cRxLock and cTxLock members of the queue data structure.
408 These locks count the number items received and sent to the queue while
409 the queue was locked. These are later used to unblock tasks waiting on
410 the queue when the queue is unlocked. This PR caps the values of the
411 cRxLock and cTxLock to the number of tasks in the system because we cannot
412 unblock more tasks than there are in the system. Note that the same assert
413 could still be triggered is the application creates more than 127 tasks.
414 + Changed uxAutoReload parameter in timer functions to xAutoReload. The
415 type is now BaseType_t. This matches the type of pdTRUE and pdFALSE.
416 The new function xTimerGetAutoReload() provides the auto-reload state as
417 a BaseType_t. The legacy function uxTimerGetAutoReload is retained with the
418 original UBaseType_t return value.
419 + Fix support for user implementations of tickless idle that call
420 vTaskStepTick() with xExpectedIdleTime ticks to step. The new code
421 ensures xTickCount reaches xNextTaskUnblockTime inside xTaskIncrementTick()
422 instead of inside vTaskStepTick(). This fixes the typical case where a task
423 wakes up one tick late and a rare case assertion failure when xTickCount\
424 rolls over. Contributed by @jefftenney.
425 + Fix deadlock in event groups when pvPortMalloc and vPortFree functions
426 are protected with a mutex. Contributed by @clemenskresser.
427 + Fix a warning in tasks.c when compiled with -Wduplicated-branches
428 GCC option. Contributed by @pierrenoel-bouteville-act.
429 + Fix compilation error in tasks.c when configSUPPORT_DYNAMIC_ALLOCATION
430 is set to zero. Contributed by @rdpoor.
431 + Fix prvWriteMessageToBuffer() function in stream_buffer.c so that it correctly
432 copies length on big endian platforms too.
433 + Remove the need for INCLUDE_vTaskSuspend to be set to 1
434 when configUSE_TICKLESS_IDLE is enabled. Contributed by @pramithkv.
435 + Update the RL78 IAR port to the latest version of IAR which uses the
436 industry standard ELF format as opposed to earlier UBROF object format.
437 Contributed by @felipe-iar.
438 + Add tick type is atomic flag when tick count is 16-bit to PIC24 port. This
439 allows the PIC24 family of 16 bit processors to read the tick count without
440 a critical section when the tick count is also 16 bits.
441 + Fix offset-out-of-range errors for GCC CM3/CM4 mpu ports when
442 Link Time Optimization is enabled. Contributed by @niniemann.
443 + Remove #error when RISC-V port is compiled on a 64-bit RISC-V platform.
444 Contributed by @cmdrf.
445 + Fix ullPortInterruptNesting alignment in Cortex-A53 port so that it is
446 8-byte aligned. This fixes the unaligned access exception. Contributed
448 + Fix Interrupt Handler Register Function and Exception Process in NiosII
449 Port. Contributed by @ghost.
450 + Change FreeRTOS IRQ Handler for Cortex-A53 SRE port to store and restore
451 interrupt acknowledge register. This ensures that the SRE port behavior
452 matches the Memory Mapped IO port. Contributed by @sviaunxp.
453 + Update the uncrustify config file to match the version of the uncrustify
454 used in the CI Action. Also, pin the version of uncrustify in CI. Contributed
457 Changes between FreeRTOS V10.4.5 and FreeRTOS V10.4.6 released November 12 2021
459 + ARMv7-M and ARMv8-M MPU ports – prevent non-kernel code from calling the
460 internal functions xPortRaisePrivilege and vPortResetPrivilege by changing
462 + Introduce a new config configALLOW_UNPRIVILEGED_CRITICAL_SECTIONS which
463 enables developers to prevent critical sections from unprivileged tasks.
464 It defaults to 1 for backward compatibility. Application should set it to
465 0 to disable critical sections from unprivileged tasks.
467 Changes between FreeRTOS V10.4.4 and FreeRTOS V10.4.5 released September 10 2021
469 See https://www.FreeRTOS.org/FreeRTOS-V10.4.5.html
471 + Introduce configRUN_TIME_COUNTER_TYPE which enables developers to define
472 the type used to hold run time statistic counters. Defaults to uint32_t
473 for backward compatibility. #define configRUN_TIME_COUNTER_TYPE to a type
474 (for example, uint64_t) in FreeRTOSConfig.h to override the default.
475 + Introduce ulTaskGetIdleRunTimePercent() to complement the pre-existing
476 ulTaskGetIdleRunTimeCounter(). Whereas the pre-existing function returns
477 the raw run time counter value, the new function returns the percentage of
478 the entire run time consumed by the idle task. Note the amount of idle
479 time is only a good measure of the slack time in a system if there are no
480 other tasks executing at the idle priority, tickless idle is not used, and
481 configIDLE_SHOULD_YIELD is set to 0.
482 + ARMv8-M secure-side port: Tasks that call secure functions from the
483 non-secure side of an ARMv8-M MCU (ARM Cortex-M23 and Cortex-M33) have two
484 contexts - one on the non-secure side and one on the secure-side. Previous
485 versions of the FreeRTOS ARMv8-M secure-side ports allocated the structures
486 that reference secure-side contexts at run time. Now the structures are
487 allocated statically at compile time. The change necessitates the
488 introduction of the secureconfigMAX_SECURE_CONTEXTS configuration constant,
489 which sets the number of statically allocated secure contexts.
490 secureconfigMAX_SECURE_CONTEXTS defaults to 8 if left undefined.
491 Applications that only use FreeRTOS code on the non-secure side, such as
492 those running third-party code on the secure side, are not affected by
495 Changes between FreeRTOS V10.4.3 and FreeRTOS V10.4.4 released May 28 2021
496 + Minor performance improvements to xTaskIncrementTick() achieved by providing
497 macro versions of uxListRemove() and vListInsertEnd().
498 + Minor refactor of timers.c that obsoletes the need for the
499 tmrCOMMAND_START_DONT_TRACE macro and removes the need for timers.c to
500 post to its own event queue. A consequence of this change is that auto-
501 reload timers that miss their intended next execution time will execute
502 again immediately rather than executing again the next time the command
503 queue is processed. (thanks Jeff Tenney).
504 + Fix a race condition in the message buffer implementation. The
505 underlying cause was that length and data bytes are written and read as
506 two distinct operations, which both modify the size of the buffer. If a
507 context switch occurs after adding or removing the length bytes, but
508 before adding or removing the data bytes, then another task may observe
509 the message buffer in an invalid state.
510 + The xTaskCreate() and xTaskCreateStatic() functions accept a task priority
511 as an input parameter. The priority has always been silently capped to
512 (configMAX_PRIORITIES - 1) should it be set to a value above that priority.
513 Now values above that priority will also trigger a configASSERT() failure.
514 + Replace configASSERT( pcQueueName ) in vQueueAddToRegistry with a NULL
516 + Introduce the configSTACK_ALLOCATION_FROM_SEPARATE_HEAP configuration
517 constant that enables the stack allocated to tasks to come from a heap other
518 than the heap used by other memory allocations. This enables stacks to be
519 placed within special regions, such as fast tightly coupled memory.
520 + If there is an attempt to add the same queue or semaphore handle to the
521 queue registry more than once then prior versions would create two separate
522 entries. Now if this is done the first entry is overwritten rather than
524 + Update the ESP32 port and TF-M (Trusted Firmware M)code to the latest from
525 their respective repositories.
526 + Correct a build error in the POSIX port.
527 + Additional minor formatting updates, including replacing tabs with spaces
529 + Other minor updates include adding additional configASSERT() checks and
530 correcting and improving code comments.
531 + Go look at the smp branch to see the progress towards the Symmetric
532 Multiprocessing Kernel. https://github.com/FreeRTOS/FreeRTOS-Kernel/tree/smp
534 Changes between FreeRTOS V10.4.2 and FreeRTOS V10.4.3 released December 14 2020
536 V10.4.3 is included in the 202012.00 LTS release. Learn more at https:/freertos.org/lts-libraries.html
538 See https://www.FreeRTOS.org/FreeRTOS-V10.4.x.html
540 + Changes to improve robustness and consistency for buffer allocation in
541 the heap, queue and stream buffer.
542 + The following functions can no longer be called from unprivileged code.
543 - xTaskCreateRestricted
544 - xTaskCreateRestrictedStatic
545 - vTaskAllocateMPURegions
548 Changes between FreeRTOS V10.4.1 and FreeRTOS V10.4.2 released November 10 2020
550 See https://www.FreeRTOS.org/FreeRTOS-V10.4.x.html
552 + Fix an issue in the ARMv8-M ports that caused BASEPRI to be masked
553 between the first task starting to execute and that task making
555 + Introduced xTaskDelayUntil(), which is functionally equivalent to
556 vTaskDelayUntil(), with the addition of returning a value to
557 indicating whether or not the function placed the calling task into
558 the Blocked state or not.
559 + Update WolfSSL to 4.5.0 and add the FIPS ready demo.
560 + Add support for ESP IDF 4.2 to ThirdParty Xtensa port.
561 + Re-introduce uxTopUsedPriority to support OpenOCD debugging.
562 + Convert most dependent libraries in FreeRTOS/FreeRTOS to submodules.
563 + Various general maintenance and improvements to MISRA compliance.
566 Changes between FreeRTOS V10.4.0 and FreeRTOS V10.4.1 released September 17 2020
568 See https://www.FreeRTOS.org/FreeRTOS-V10.4.x.html
570 + Fixed an incorrectly named parameter that prevented the
571 ulTaskNotifyTakeIndexed macro compiling, and the name space clash in the
572 test code that prevented this error causing test failures.
575 Changes between FreeRTOS V10.3.1 and FreeRTOS V10.4.0 released September 10 2020
577 See https://www.FreeRTOS.org/FreeRTOS-V10.4.x.html
581 + Task notifications: Prior to FreeRTOS V10.4.0 each created task had a
582 single direct to task notification. From FreeRTOS V10.4.0 each task has
583 an array of notifications. The direct to task notification API has been
584 extended with API functions postfixed with "Indexed" to enable the API to
585 operate on a task notification at any array index. See
586 https://www.freertos.org/RTOS-task-notifications.html for more information.
587 + Kernel ports that support memory protection units (MPUs): The ARMv7-M and
588 ARMv8-M MPU ports now support a privilege access only heap. The ARMv7-M
589 MPU ports now support devices that have 16 MPU regions, have the ability
590 to override default memory attributes for privileged code and data
591 regions, and have the ability to place the FreeRTOS kernel code outside of
592 the Flash memory. The ARMv8-M MPU ports now support tickless idle mode.
593 See https://www.freertos.org/FreeRTOS-MPU-memory-protection-unit.html
594 for more information.
596 Additional noteworthy updates:
598 + Code formatting is now automated to facilitate the increase in
599 collaborative development in Git. The auto-formated code is not identical
600 to the original formatting conventions. Most notably spaces are now used
602 + The prototypes for callback functions (those that start with "Application",
603 such as vApplicationStackOverflowHook()) are now in the FreeRTOS header
604 files, removing the need for application writers to add prototypes into
605 the C files in which they define the functions.
606 + New Renesas RXv3 port layer.
607 + Updates to the Synopsys ARC code, including support for EM and HS cores,
609 + Added new POSIX port layer that allows FreeRTOS to run on Linux hosts in
610 the same way the Windows port layer enables FreeRTOS to run on Windows
612 + Many other minor optimisations and enhancements. For full details
613 see https://github.com/FreeRTOS/FreeRTOS-Kernel/commits/main
616 Changes between FreeRTOS V10.3.0 and FreeRTOS V10.3.1 released February 18 2020
618 See https://www.FreeRTOS.org/FreeRTOS-V10.3.x.html
620 + ./FreeRTOS-Labs directory was removed from this file. The libraries it
621 contained are now available as a separate download.
623 Changes between FreeRTOS V10.2.1 and FreeRTOS V10.3.0 released February 7 2020
625 See https://www.FreeRTOS.org/FreeRTOS-V10.3.x.html
627 New and updated kernel ports:
629 + Added RISC-V port for the IAR compiler.
630 + Update the Windows simulator port to use a synchronous object to prevent
631 a user reported error whereby a task continues to run for a short time
632 after being moved to the Blocked state. Note we were not able to
633 replicate the reported issue and it likely depends on your CPU model.
634 + Correct alignment of stack top in RISC-V port when
635 configISR_STACK_SIZE_WORDS is defined to a non zero value, which causes
636 the interrupt stack to be statically allocated.
637 + The RISC-V machine timer compare register can now be for any HART, whereas
638 previously it was always assumed FreeRTOS was running on HART 0.
639 + Update the sequence used to update the 64-bit machine timer
640 compare register on 32-bit cores to match that suggested in RISC-V
642 + Added tickless low power modes into the ARM, IAR and GCC Cortex-M0 compiler
644 + Updated the behaviour of the ARMv7-M MPU (Memory Protection Unit) ports to
645 match that of the ARMv8-M ports whereby privilege escalations can only
646 originate from within the kernel's own memory segment. Added
647 configENFORCE_SYSTEM_CALLS_FROM_KERNEL_ONLY configuration constant.
648 + Update existing MPU ports to correctly disable the MPU before it is
650 + Added contributed port and demo application for a T-Head (formally C-SKY)
655 + Added the vPortGetHeapStats() API function which returns information on
656 the heap_4 and heap_5 state.
657 + Added xTaskCatchUpTicks(), which corrects the tick count value after the
658 application code has held interrupts disabled for an extended period.
659 + Added xTaskNotifyValueClear() API function.
660 + Added uxTimerGetReloadMode() API function.
662 Other miscellaneous changes:
663 + Change type of uxPendedTicks from UBaseType_t to TickType_t to ensure it
664 has the same type as variables with which it is compared to, and therefore
665 also renamed the variable xPendingTicks.
666 + Update Keil projects that use the MPU so memory regions come from linker
667 script (scatter file) variables instead of being hard coded.
668 + Added LPC51U68 Cortex-M0+ demos for GCC (MCUXpresso), Keil and IAR
670 + Added CORTEX_MPU_STM32L4_Discovery_Keil_STM32Cube demo.
671 + Added LPC54018 MPU demo.
672 + Rename xTaskGetIdleRunTimeCounter() to ulTaskGetIdleRunTimeCounter().
675 Changes between FreeRTOS V10.2.1 and FreeRTOS V10.2.0 released May 13 2019:
677 + Added ARM Cortex-M23 port layer to complement the pre-existing ARM
678 Cortex-M33 port layer.
679 + The RISC-V port now automatically switches between 32-bit and 64-bit
681 + Introduced the portMEMORY_BARRIER macro to prevent instruction re-ordering
682 when GCC link time optimisation is used.
683 + Introduced the portDONT_DISCARD macro to the ARMv8-M ports to try and
684 prevent the secure side builds from removing symbols required by the
685 non secure side build.
686 + Introduced the portARCH_NAME to provide additional data to select semi-
687 automated build environments.
688 + Cortex-M33 and Cortex-M23 ports now correctly disable the MPU before
689 updating the MPU registers.
691 + Added Nuvoton NuMaker-PFM-M2351 ARM Cortex-M23 demo.
692 + Added LPC55S69 ARM Cortex-M33 demo.
693 + Added an STM32 dual core AMP stress test demo.
696 Changes between FreeRTOS V10.1.1 and FreeRTOS V10.2.0 released February 25 2019:
698 + Added GCC RISC-V MCU port with three separate demo applications.
699 + Included pre-existing ARM Cortex-M33 (ARMv8-M) GCC/ARMclang and IAR ports
700 with Keil simulator demo.
701 + Update the method used to detect if a timer is active. Previously the
702 timer was deemed to be inactive if it was not referenced from a list.
703 However, when a timer is updated it is temporarily removed from, then
704 re-added to a list, so now the timer's active status is stored separately.
705 + Add vTimerSetReloadMode(), xTaskGetIdleRunTimeCounter(), and
706 xTaskGetApplicationTaskTagFromISR() API functions.
707 + Updated third party Xtensa port so it is MIT licensed.
708 + Added configINCLUDE_PLATFORM_H_INSTEAD_OF_IODEFINE_H to the Renesas
709 compiler RX600v2 port to enable switching between platform.h and
710 iodefine.h includes within that port's port.c file.
711 + Removed the 'FromISR' functions from the MPU ports as ISRs run privileged
713 + Added uxTaskGetStackHighWaterMark2() function to enable the return type to
714 be changed without breaking backward compatibility.
715 uxTaskGetStackHighWaterMark() returns a UBaseType_t as always,
716 uxTaskGetStackHighWaterMark2() returns configSTACK_DEPTH_TYPE to allow the
717 user to determine the return type.
718 + Fixed issues in memory protected ports related to different combinations
719 of static memory only and dynamic memory only builds. As a result the
720 definition of tskSTATIC_AND_DYNAMIC_ALLOCATION_POSSIBLE became more
721 complex and was moved to FreeRTOS.h with a table explaining its definition.
722 + Added a 'get task tag from ISR' function.
723 + Change the method used to determine if a timer is active or not from just
724 seeing if it is referenced from the active timer list to storing its
725 active state explicitly. The change prevents the timer reporting that it
726 is inactive while it is being moved from one list to another.
727 + The pcName parameter passed into the task create functions can be NULL,
728 previously a name had to be provided.
729 + When using tickless idle, prvResetNextTaskUnblockTime() is now only called
730 in xTaskRemoveFromEventList() if the scheduler is not suspended.
731 + Introduced portHAS_STACK_OVERFLOW_CHECKING, which should be set to 1 for
732 FreeRTOS ports that run on architectures that have stack limit registers.
735 Changes between FreeRTOS V10.1.0 and FreeRTOS V10.1.1 released 7 September 2018
737 + Reverted a few structure name changes that broke several kernel aware
739 + Updated to the latest trace recorder code.
740 + Fixed some formatting in the FreeRTOS+TCP TCP/IP stack code.
741 + Reverted moving some variables from file to function scope as doing so
742 broke debug scenarios that require the static qualifier to be removed.
744 Changes between FreeRTOS V10.0.1 and FreeRTOS V10.1.0 released 22 August 2018
746 FreeRTOS Kernel Changes:
748 + Update lint checked MISRA compliance to use the latest MISRA standard, was
749 previously using the original MISRA standard.
750 + Updated all object handles (TaskHandle_t, QueueHandle_t, etc.) to be
751 unique types instead of void pointers, improving type safety. (this was
752 attempted some years back but had to be backed out due to bugs in some
753 debuggers). Note this required the pvContainer member of a ListItem_t
754 struct to be renamed - set configENABLE_BACKWARD_COMPATIBILITY to 1 if
755 this causes an issue.
756 + Added configUSE_POSIX_ERRNO to enable per task POSIX style errno
757 functionality in a more user friendly way - previously the generic thread
758 local storage feature was used for this purpose.
759 + Added Xtensa port and demo application for the XCC compiler.
760 + Changed the implementation of vPortEndScheduler() for the Win32 port to
761 simply call exit( 0 ).
762 + Bug fix in vPortEnableInterrupt() for the GCC Microblaze port to protect
763 the read modify write access to an internal Microblaze register.
764 + Fix minor niggles when the MPU is used with regards to prototype
765 differences, static struct size differences, etc.
766 + The usStackHighWaterMark member of the TaskStatus_t structure now has type
767 configSTACK_DEPTH_TYPE in place of uint16_t - that change should have been
768 made when the configSTACK_DEPTH_TYPE type (which gets around the previous
769 16-bit limit on stack size specifications) was introduced.
770 + Added the xMessageBufferNextLengthBytes() API function and likewise stream
772 + Introduce configMESSAGE_BUFFER_LENGTH_TYPE to allow the number of bytes
773 used to hold the length of a message in the message buffer to be reduced.
774 configMESSAGE_BUFFER_LENGTH_TYPE default to size_t, but if, for example,
775 messages can never be more than 255 bytes it could be set to uint8_t,
776 saving 3 bytes each time a message is written into the message buffer
777 (assuming sizeof( size_t ) is 4).
778 + Updated the StaticTimer_t structure to ensure it matches the size of the
779 Timer_t structure when the size of TaskFunction_t does not equal the size
781 + Update various Xilinx demos to use 2018.1 version of the SDK tools.
782 + Various updates to demo tasks to maintain test coverage.
783 + FreeRTOS+UDP was removed in FreeRTOS V10.1.0 as it was replaced by
784 FreeRTOS+TCP, which was brought into the main download in FreeRTOS
785 V10.0.0. FreeRTOS+TCP can be configured as a UDP only stack, and
786 FreeRTOS+UDP does not contain the patches applied to FreeRTOS+TCP.
788 FreeRTOS+TCP Changes:
790 + Multiple security improvements and fixes in packet parsing routines, DNS
791 caching, and TCP sequence number and ID generation.
792 + Disable NBNS and LLMNR by default.
793 + Add TCP hang protection by default.
795 We thank Ori Karliner of Zimperium zLabs Team for reporting these issues.
798 Changes between FreeRTOS V10.0.0 and FreeRTOS V10.0.1, released December 20 2017
800 + Fix position of "#if defined( __cplusplus )" in stream_buffer.h.
801 + Correct declarations of MPU_xQueuePeek() and MPU_xQueueSemaphoreTake() in
803 + Correct formatting in vTaskList() helper function when it prints the state
804 of the currently executing task.
805 + Introduce #error if stream_buffer.c is built without
806 configUSE_TASK_NOTIFICATIONS set to 1.
807 + Update FreeRTOS+TCP to V2.0.0
808 - Improve the formatting of text that displays the available netword
809 interfaces when FreeRTOS+TCP is used on Windows with WinPCap.
810 - Introduce ipconfigSOCKET_HAS_USER_WAKE_CALLBACK option to enable a user
811 definable callback to execute when data arrives on a socket.
813 Changes between FreeRTOS V9.0.1 and FreeRTOS V10.0.0:
815 The FreeRTOS kernel is now MIT licensed: https://www.FreeRTOS.org/license
817 New Features and components:
819 + Stream Buffers - see https://www.FreeRTOS.org/RTOS-stream-buffer-example.html
820 + Message Buffers - see https://www.FreeRTOS.org//RTOS-message-buffer-example.html
821 + Move FreeRTOS+TCP into the main repository, along with the basic Win32
822 TCP demo FreeRTOS_Plus_TCP_Minimal_Windows_Simulator.
826 + Added demo for TI SimpleLink CC3220 MCU.
827 + Added MPU and non MPU projects for Microchip CEC and MEC 17xx and 51xx
829 + Added CORTEX_MPU_Static_Simulator_Keil_GCC demo to test static allocation
832 Fixes or enhancements:
834 + Cortex-M ports push additional register prior to calling
835 vTaskSwitchContext to ensure 8-byte alignment is maintained. Only
836 important if a user defined tick hook function performs an operation that
837 requires 8-byte alignment.
838 + Optimisations to the implementation of the standard tickless idle mode on
840 + Improvements to the Win32 port including using higher priority threads.
841 + Ensure interrupt stack alignment on PIC32 ports.
842 + Updated GCC TriCore port to build with later compiler versions.
843 + Update mpu_wrappers.c to support static allocation.
844 + The uxNumberOfItems member of List_t is now volatile - solving an issue
845 when the IAR compiler was used with maximum optimization.
846 + Introduced configRECORD_STACK_HIGH_ADDRESS. When set to 1 the stack start
847 address is saved into each task's TCB (assuming stack grows down).
848 + Introduced configINCLUDE_FREERTOS_TASK_C_ADDITIONS_H to allow user defined
849 functionality, and user defined initialisation, to be added to FreeRTOS's
850 tasks.c source file. When configINCLUDE_FREERTOS_TASK_C_ADDITIONS_H is
851 set to 1 a user provided header file called freertos_task_c_additions.h
852 will be included at the bottom of tasks.c. Functions defined in that
853 header file can call freertos_tasks_c_additions_init(), which in turn
854 calls a macro called FREERTOS_TASKS_C_ADDITIONS_INIT(), if it is defined.
855 FREERTOS_TASKS_C_ADDITIONS_INIT() can be defined in FreeRTOSConfig.h.
856 + Introduced configPRE_SUPPRESS_TICKS_AND_SLEEP_PROCESSING( x ) which can be
857 defined by a user in FreeRTOSConfig.h. The macro is called before
858 assessing whether to enter tickless idle mode or not. If the macro sets
859 x to zero then tickless idle mode will not be entered. This allows users
860 to abort tickless idle mode entry before the tickless idle function is
861 even called - previously it was only possible to abort from within the
862 tickless idle function itself.
863 + Added configPRINTF(), which can be defined by users to allow all libraries
864 to use the same print formatter.
865 + Introduced configMAX() and configMIN() macros which default to standard
866 max( x, y ) and min( x, y ) macro behaviour, but can be overridden if the
867 application writer defines the same macros in FreeRTOSConfig.h.
868 + Corrected the definition of StaticTask_t in the case where
869 INCLUDE_xTaskAbortDelay is set to 1.
870 + Introduced configTIMER_SERVICE_TASK_NAME and configIDLE_TASK_NAME, both of
871 which can be defined to strings in FreeRTOSConfig.h to change the default
872 names of the timer service and idle tasks respectively.
873 + Only fill the stack of a newly created task with a known value if stack
874 checking, or high water mark checking/viewing, is in use - removing the
875 dependency on memset() in other cases.
876 + Introduced xTaskCreateRestrictedStatic() so static allocation can be used
878 + Ensure suspended tasks cannot be unsuspended by a received task
880 + Fix race condition in vTaskSetTimeOutState().
881 + Updated trace recorder files to the latest version.
883 Changes since FreeRTOS V9.0.0:
885 + Priority dis-inheritance behaviour has been enhanced in the case where a
886 task that attempted to take a mutex that was held by a lower priority task
887 timed out before it was able to obtain the mutex (causing the task that
888 holds the mutex to have its priority raised, then lowered again, in
889 accordance with the priority inheritance protocol).
890 + Split the overloaded xQueueGenericReceive() function into three separate
892 + Allow the default human readable text names given to the Idle and Timer
893 tasks to be overridden by defining the configIDLE_TASK_NAME and
894 configTIMER_SERVICE_TASK_NAME definitions respectively in FreeRTOSConfig.h.
895 + Introduced configINITIAL_TICK_COUNT to allow the tick count to take a
896 value of than than 0 when the system boots. This can be useful for
897 testing purposes - although setting configUSE_16_BIT_TICKS to 1 can also
898 be used to test frequent tick overflows.
899 + Ensure the Cortex-M SysTick count is cleared to zero before starting the
901 + Add configASSERT() into ARM Cortex-M ports to check the number of priority
903 + Clear the 'control' register before starting ARM Cortex-M4F ports in case
904 the FPU is used before the scheduler is started. This just saves a few
905 bytes on the main stack as it prevents space being left for a later save
907 + Added xSemaphoreGetMutexHolderFromISR().
908 + Corrected use of portNVIC_PENDSVSET to portNVIC_PENDSVSET_BIT in MPU ports.
909 + Introduced configSTACK_DEPTH_TYPE to allow users to change the type used
910 to specify the stack size when using xTaskCreate(). For historic reasons,
911 when FreeRTOS was only used on small MCUs, the type was set to uint16_t,
912 but that can be too restrictive when FreeRTOS is used on larger
913 processors. configSTACK_DEPTH_TYPE defaults to uint16_t.
914 xTaskCreateStatic(), being a newer function, used a uint32_t.
915 + Increase the priority of the Windows threads used by the Win32 port. As
916 all the threads run on the same core, and the threads run with very high
917 priority, there is a risk that the host will become unresponsive, so also
918 prevent the Windows port executing on single core hosts.
920 Changes between FreeRTOS V9.0.0 and FreeRTOS V9.0.0rc2 released May 25 2016:
922 See https://www.FreeRTOS.org/FreeRTOS-V9.html
926 + The prototype of the new xTaskCreateStatic() API function was modified to
927 remove a parameter and improve compatibility with other new
928 "CreateStatic()" API functions. The stack size parameter in
929 xTaskCreateStatic() is now uint32_t, which changes the prototype of the
930 callback functions. See the following URL:
931 https://www.FreeRTOS.org/xTaskCreateStatic.html
932 + GCC ARM Cortex-A port: Introduced the configUSE_TASK_FPU_SUPPORT
933 constant. When configUSE_TASK_FPU_SUPPORT is set to 2 every task is
934 automatically given a floating point (FPU) context.
935 + GCC ARM Cortex-A port: It is now possible to automatically save and
936 restore all floating point (FPU) registers on entry to each potentially
937 nested interrupt by defining vApplicationFPUSafeIRQHandler() instead of
938 vApplicationIRQHandler().
939 + All ARM Cortex-M3/4F/7 ports: Clear the least significant bit of the task
940 entry address placed onto the stack of a task when the task is created for
941 strict compliance with the ARM Cortex-M3/4/7 architecture documentation
942 (no noticeable effect unless using the QMEU emulator).
943 + Added GCC and Keil ARM Cortex-M4F MPU ports - previously the MPU was only
944 supported on ARM Cortex-M3.
945 + ARM Cortex-M3/4F MPU ports: Update to fully support the FreeRTOS V9.0.0
946 API (other than static object creation) and added the
947 FreeRTOS/Demo/CORTEX_MPU_Simulator_Keil_GCC demo application to
948 demonstrate how to use the updated MPU port.
949 + All ARM Cortex-M3/4F/7 ports: Add additional barrier instructions to the
950 default low power tickless implementation.
951 + All ARM Cortex-M0 ports: Prevent an item being left on the stack of the
952 first task that executes.
953 + Win32 ports: Reduce the amount of stack used and change the way Windows
954 threads are deleted to increase the maximum execution time.
955 + Add an ARM Cortex-M4F port for the MikroC compiler. Ensure to read the
956 documentation page for this port before use.
957 + MPS430X IAR port: Update to be compatible with the latest EW430 tools
959 + IAR32 GCC port: Correct vPortExitCritical() when
960 configMAX_API_CALL_INTERRUPT_PRIORITY == portMAX_PRIORITY.
961 + For consistency vTaskGetTaskInfo() now has the alias vTaskGetInfo(),
962 xTaskGetTaskHandle() now has the alias xTaskGetHandle() and
963 pcQueueGetQueueName() now has an alias pcQueueGetName().
964 + Fix various errors in comments and compiler warnings.
966 Demo application updates:
968 + Update Atmel Studio projects to use Atmel Studio 7.
969 + Update Xilinx SDK projects to use the 2016.1 version of the SDK.
970 + Remove dependency on legacy IO libraries from the PIC32 demos.
971 + Move the Xilinx UltraScale Cortex-R5 demo into the main distribution.
972 + Update the MSP432 libraries to the latest version.
973 + Add Microchip CEC1302 (ARM Cortex-M4F) demos for GCC, Keil and MikroC
975 + Move the Atmel SAMA5D2 demo into the main distribution.
977 Changes between FreeRTOS V9.0.0rc1 and FreeRTOS V9.0.0rc2 (release candidate 2)
978 released March 30 2016:
980 NOTE - See https://www.FreeRTOS.org/FreeRTOS-V9.html for details
982 + The functions that create RTOS objects using static memory allocation have
983 been simplified and will not revert to using dynamic allocation if a
984 buffer is passed into a function as NULL.
985 + Introduced the configSUPPORT_DYNAMIC_ALLOCATION configuration constant to
986 allow a FreeRTOS application to be built without a heap even being being
987 defined. The Win32 example located in the
988 /FreeRTOS/demo/WIN32-MSVC-Static-Allocation-Only directory is provided as
989 a reference for projects that do not include a FreeRTOS heap.
990 + Minor run-time optimisations.
991 + Two new low power tickless implementations that target Silicon Labs EFM32
993 + Addition of the xTimerGetPeriod() and xTimerGetExpireTime() API functions.
995 Changes between FreeRTOS V8.2.3 and FreeRTOS V9.0.0rc1 (release candidate 1)
996 released February 19 2016:
1000 + Major new feature - tasks, semaphores, queues, timers and event groups can
1001 now be created using statically allocated memory, so without any calls to
1003 + Major new features - Added the xTaskAbortDelay() API function which allows
1004 one task to force another task to immediately leave the Blocked state,
1005 even if the event the blocked task is waiting for has not occurred, or the
1006 blocked task's timeout has not expired.
1007 + Updates necessary to allow FreeRTOS to run on 64-bit architectures.
1008 + Added vApplicationDaemonTaskStartupHook() which executes when the RTOS
1009 daemon task (which used to be called the timer service task) starts
1010 running. This is useful if the application includes initialisation code
1011 that would benefit from executing after the scheduler has been started.
1012 + Added the xTaskGetTaskHandle() API function, which obtains a task handle
1013 from the task's name. xTaskGetTaskHandle() uses multiple string compare
1014 operations, so it is recommended that it is called only once per task.
1015 The handle returned by xTaskGetTaskHandle() can then be stored locally for
1017 + Added the pcQueueGetQueueName() API function, which obtains the name of
1018 a queue from the queue's handle.
1019 + Tickless idling (for low power applications) can now also be used when
1020 configUSE_PREEMPTION is 0.
1021 + If one task deletes another task, then the stack and TCB of the deleted
1022 task is now freed immediately. If a task deletes itself, then the stack
1023 and TCB of the deleted task are freed by the Idle task as before.
1024 + If a task notification is used to unblock a task from an ISR, but the
1025 xHigherPriorityTaskWoken parameter is not used, then pend a context switch
1026 that will then occur during the next tick interrupt.
1027 + Heap_1.c and Heap_2.c now use the configAPPLICATION_ALLOCATED_HEAP
1028 settings, which previously was only used by heap_4.c.
1029 configAPPLICATION_ALLOCATED_HEAP allows the application writer to declare
1030 the array that will be used as the FreeRTOS heap, and in-so-doing, place
1031 the heap at a specific memory location.
1032 + TaskStatus_t structures are used to obtain details of a task.
1033 TaskStatus_t now includes the bae address of the task's stack.
1034 + Added the vTaskGetTaskInfo() API function, which returns a TaskStatus_t
1035 structure that contains information about a single task. Previously this
1036 information could only be obtained for all the tasks at once, as an array
1037 of TaskStatus_t structures.
1038 + Added the uxSemaphoreGetCount() API function.
1039 + Replicate previous Cortex-M4F and Cortex-M7 optimisations in some
1040 Cortex-M3 port layers.
1042 Demo Application Updates:
1044 Further demo applications will be added prior to the final FreeRTOS V9
1047 + Updated SAM4L Atmel Studio project to use Atmel Studio 7.
1048 + Added ARM Cortex-A53 64-bit port.
1049 + Added a port and demo for the ARM Cortex-A53 64-bit cores on the Xilinx
1051 + Added Cortex-M7 SAME70 GCC demo.
1052 + Added EFM32 Giant and Wonder Gecko demos.
1055 Changes between V8.2.2 and V8.2.3 released October 16, 2015
1057 RTOS kernel updates:
1059 + Fix bug identified in a modification made in V8.2.2 to the software timer
1060 code that allows tickless low power applications to sleep indefinitely
1061 when software timers are used.
1062 + Simplify and improve efficiency of stack overflow checking.
1063 + Add xTaskNotifyStateClear() API function.
1064 + New IAR and GCC Cortex-R ports for microprocessors that do not use an ARM
1065 generic interrupt controller (GIC).
1066 + New PIC32MEC14xx port.
1067 + Add support for PIC32MZ EF parts (with floating point) into the PIC32MZ
1069 + Zynq7000 port layer now declares the functions that setup and clear the
1070 tick interrupt as weak symbols so they can be overridden by the
1071 application, and uses a global XScuGic object so the same object can be
1072 used by the application code.
1073 + Introduced configUSE_TASK_FPU_SUPPORT, although the PIC32MZ EF port is
1074 currently the only port that uses it.
1075 + Updates to RL78 and 78K0 IAR port layers to improve support for
1076 combinations of memory models.
1077 + Minor updates to heap_5.c to remove compiler warnings generated by some
1079 + License simplifications. See /FreeRTOS/License/license.txt in the
1080 official distribution.
1084 + Update directory names to use WolfSSL instead of CyaSSL, inline with
1085 WolfSSL's re-branding.
1086 + Update to latest WolfSSL code.
1087 + Update to latest FreeRTOS+Trace recorder code.
1088 + Add in the FreeRTOS+Trace recorder library required for streaming trace.
1090 Demo application changes:
1092 + Add demo applications for Renesas RZ/T (Cortex-R), PIC32MZ EF (PIC32 with
1093 floating point hardware), PIC32MEC14xx, RX71M, RX113 and RX231.
1094 + General tidy up of spelling and compiler warnings.
1097 Changes between V8.2.1 and V8.2.2 released August 12, 2015
1099 RTOS kernel updates:
1101 + Added Intel IA32/x86 32-bit port.
1102 + General maintenance.
1103 + PRIVILEGED_FUNCTION and PRIVILEGED_DATA macros, which are used in memory
1104 protected systems, have been added to the newer event group and software
1106 + Add the errno definitions used by FreeRTOS+ components into projdefs.h.
1107 + Remove the restriction that prevented tick-less idle implementations
1108 waiting indefinitely when software timers were used in the same
1110 + Introduce xTaskNotifyAndQueryFromISR() as the interrupt safe version of
1111 xTaskNotifyAndQuery().
1112 + Add additional NOPs to the MSP430X port layers to ensure strict compliance
1113 with the hardware documentation.
1114 + Microblaze port: Added option for port optimised task selection.
1115 + Microblaze port: Previously tasks inherited the exception enable state
1116 at the time the task was created. Now all tasks are created with
1117 exceptions enabled if the Microblaze design supports exceptions.
1118 + Windows port: Add additional safe guards to ensure the correct start up
1119 sequence and thread switching timing.
1120 + Windows port: Improve the implementation of the port optimised task
1121 selection assembly code.
1122 + Update heap_4 and heap_5 to allow use on 64-bit processors.
1123 + Simplify the code that creates a queue.
1124 + General improved tick-less idle behaviour.
1125 + Ensure none of the variables in the common kernel files are initialised to
1126 anything other than zero.
1127 + Correct calculation of xHeapStructSize in heap_4 and heap_5.
1129 Demo application updates:
1131 + Added demo project for the new IA32/x86 port that targets the Galileo
1133 + Added MSP430FR5969 demos (previously provided as a separate download).
1134 + Added FreeRTOS BSP repository for automatic creation of FreeRTOS
1135 applications in the Xilinx SDK.
1136 + Added Atmel Studio / GCC project for the SAMV71 (ARM Cortex-M7)
1137 + Update Xilinx SDK projects to use version 2015.2 of the SDK.
1138 + Remove Microblaze demos that were using obsolete tools.
1139 + Add MSP43FR5969 IAR and CCS demos.
1143 + Updated FreeRTOS+Trace recorder library, which requires an update to the
1144 FreeRTOS+Trace application.
1145 + Added Reliance Edge source code and demo application. Reliance edge is
1146 a fail safe transactional file system ideal for applications that require
1147 file storage, and especially when high reliability is essential.
1148 + Introduce configAPPLICATION_PROVIDES_cOutputBuffer to allow FreeRTOS+CLI
1149 users to place the output buffer at a fixed memory address.
1150 + Improve the NetworkInterface.c file provided for the Windows port of
1153 Changes between V8.2.0 and V8.2.1 released 24th March 2015.
1155 RTOS kernel updates:
1157 + Added user definable and flexible thread local storage facility.
1158 + Added vTimerSetTimerID() API function to complement the pvTimerGetTimerID()
1159 function to allow the timer's ID to be used as timer local storage.
1160 + Fixed a potential issue related to the use of queue sets from an ISR.
1161 + Some updates to the Xilinx Microblaze GCC port.
1162 + Added ARM Cortex-M4F port for Texas Instruments Code Composer Studio.
1163 + Added ARM Cortex-M7 r0p1 port layer for IAR, GCC and Keil which contains a
1164 minor errata work around. All other ARM Cortex-M7 core revisions should
1165 use the ARM Cortex-M4F port.
1166 + Exclude the whole of croutine.c if configUSE_CO_ROUTINES is set to 0.
1167 + Change some data types from uint32_t to size_t in preparation for 64-bit
1169 + Update the PIC32 port to remove deprecation warnings output by the latest
1171 + Fix bug when xQueueOverwrite() and xQueueOverwrite() from ISR are used to
1172 overwrite items in two queues that are part of the same set.
1174 Demo application updates:
1176 + Added demo application for TI's ARM Cortex-M4F based MSP432
1177 microcontroller using IAR, Keil and CCS compilers.
1178 + Added demo application for STM32F ARM Cortex-M7 based microcontroller
1180 + Added demo application for Atmel SAMV71 ARM Cortex-M7 based
1181 microcontroller using IAR and Keil.
1182 + Added Microblaze demo that uses the 2014.4 version of the Xilinx SDK and
1183 runs on the KC705 evaluation board (Kintex FPGA).
1185 Changes between V8.1.2 and V8.2.0 released 16th January 2015
1187 Changes between release candidate 1 and the official release are restricted
1188 to maintenance only.
1190 Significant RTOS kernel updates:
1192 + MAJOR NEW FEATURE! Task notifications. Please see the following URL for
1193 details: https://www.FreeRTOS.org/RTOS-task-notifications.html
1194 + NEW HEADER FILE REQUIRED! Obsolete definitions have been separated into
1195 a new header file called FreeRTOS/Source/include/deprecated_definitions.h.
1196 This header file must be present to build. Note some of the obsolete
1197 definitions are still used by very old demo application projects.
1199 Other RTOS kernel updates:
1201 + Made xSemaphoreGiveFromISR() a function rather than a macro that calls
1202 xQueueGenericSendFromISR(). This allows for major performance
1203 enhancements at the expense of some additional code size if both functions
1204 are used in the same application. NOTE: In most uses cases such use of
1205 a semaphore can now be replaced with a task notification which is smaller
1207 + The TCB is now always allocated such that the task's stack grows away from
1208 the TCB (improves debugging of stack overflows as the overflow will not
1209 overwrite the task's name).
1210 + GCC, IAR and Keil Cortex-M4F ports now use more inlining (performance
1211 enhancements at the cost of a little additional code space).
1212 + Queues are now allocated with a single call to pvPortMalloc() which
1213 allocates both the queue structure and the queue storage area.
1214 + Introduced a new critical section macro for reading the tick count that
1215 defines away to nothing in cases where the width of the tick allows the
1216 tick count to be read atomically (performance benefits - especially when
1217 optimisation is on).
1218 + Introduced configAPPLICATION_ALLOCATED_HEAP in heap_4.c to allow the
1219 application writer to provide their own heap array - and in so doing
1220 control the location of the heap.
1221 + Introduced configUSE_LIST_DATA_INTEGRITY_CHECK_BYTES which, when set, will
1222 include known values in both list and list item structures. The values
1223 are intended to assist debugging. If the values get overwritten then it
1224 is likely application code has written over RAM used by the kernel.
1225 + configASSERT()s in all Cortex-M ports used to test the lowest 5 bits of
1226 the interrupt control register to detect taskENTER_CRITICAL() being called
1227 from an interrupt. This has been changed to test all 8 bits.
1228 + Introduced uxTaskPriorityGetFromISR().
1229 + Microblze V8 port now tests XPAR_MICROBLAZE_0_USE_FPU for inequality to 0
1230 rather than equality to 1, and 2 and 3 are also valid values.
1231 + Cortex-A5 GIC-less port no longer passes the address of the interrupting
1232 peripheral into the interrupt handler.
1233 + Fix an issue in FreeRTOS-MPU where an attempt was made to free the stack
1234 belonging to a task when the task was deleted, even when the stack was
1235 allocated statically.
1236 + Utility (helper) functions that format task statistic information into
1237 human readable tables now pad task names with spaces to ensure columns
1238 line up correctly even where task name lengths vary greatly.
1239 + Update FreeRTOS+Trace recorder library to version 2.7.0.
1241 Demo application updates:
1243 + Added two new standard demo task sets: IntSemTest and TaskNotify.
1244 + Added port and demo application for Atmel SAMA5D4 Cortex-A5 MPU.
1245 + Added demo application for Altera Cyclone V Cortex-A9 MPU.
1246 + Updated Zynq demo to use version 2014.4 of Xilinx's SDK and added in
1247 demo tasks for new RTOS features.
1248 + Updated Atmel SAM4E and SAM4S demos to include a lot of additional test
1250 + Fixed a corner case issue in Atmel SAM4L low power tickless
1251 implementation, and added button interrupt handling.
1252 + Make the interrupt queue tests more tolerant to heave CPU loads.
1253 + Updated MSVC FreeRTOS simulator demo to include the latest standard test
1255 + Updated MingW/Eclipse FreeRTOS simulator demo to match the FreeRTOS MSVC
1257 + Updated all demos that use FreeRTOS+Trace to work with the latest trace
1261 Changes between V8.1.1 and V8.1.2 released September 2nd 2014
1263 Move the defaulting of configUSE_PORT_OPTIMISED_TASK_SELECTION into the
1264 individual port layers where necessary so it does not affect ports that do
1265 not support the definition.
1267 Changes between V8.1.0 and V8.1.1 released August 29th 2014
1269 By popular requests - a minor patch to V8.1.0 to re-instate the ability to
1270 give a mutex type semaphore (with priority inheritance) from an interrupt
1273 Changes between V8.0.1 and V8.1.0 released August 26th 2014
1275 FreeRTOS scheduler, kernel, demo and test updates:
1277 + Improved the priority inheritance algorithms to assist integration with
1278 off the shelf middleware that may hold multiple mutexes simultaneously.
1279 + Introduce heap_5.c, which is similar to heap_4.c but allows the heap to
1280 span multiple non-contiguous memory regions.
1281 + Updated all Cortex-A9 ports to help trap a couple of common usage errors -
1282 the first being when a task incorrectly attempts to exit its implementing
1283 function and the second being when a non interrupt safe API function is
1284 called from an interrupt.
1285 + Update all Cortex-A9 ports to remove obsolete mode switches prior to
1286 restoring a task context.
1287 + configUSE_PORT_OPTIMISED_TASK_SELECTION now defaults to 1 instead of 0.
1288 + Update all Cortex-M3/4F ports to trap a non interrupt safe API function
1289 being called from an interrupt handler.
1290 + Simplify the alignment checks in heap_4.c.
1291 + Update the MSVC Windows simulator demo to use heap_5.c in place of
1292 heap_4.c to ensure end users have an example to refer to.
1293 + Updated standard demo test code to test the new priority inheritance
1295 + Updated the standard demo tasks to make use of stdint and the FreeRTOS
1296 specific typedefs that were introduced in FreeRTOS V8.0.0.
1297 + Introduce the pdMS_TO_TICKS() macro as a more user friendly and intuitive
1298 alternative to pdTICKS_PER_MS - both of which can be used to convert a
1299 time specified in milliseconds to a time specified in RTOS ticks.
1300 + Fix a bug in the Tasking compiler's Cortex-M port that resulted in an
1301 incorrect value being written to the basepri register. This only effects
1302 users of the Tasking compiler.
1303 + Update the Zynq demo to use version 2014.2 of the SDK and add in an lwIP
1304 example that demonstrates lwIP being used with both its raw and sockets
1306 + Updated the CCS Cortex-R4 port to enable it to be built with the latest
1309 New ports and demo applications:
1311 + Two Renesas RX64M ports (RXv2 core) and demos introduced, one for the GCC
1312 compiler and one for the Renesas compiler. Both demos use e2 studio.
1313 + Generic IAR Cortex-A5 port (without any reliance on a GIC) introduced.
1314 The new port is demonstrated on an Atmel SAMA5D3 XPlained board.
1316 FreeRTOS+ component updates:
1318 + Update CyaSSL to the latest version.
1319 + Updated the FreeRTOS+ components supplied directly by Real Time Engineers
1320 Ltd. to make use of stdint and the FreeRTOS specific typedefs that were
1321 introduced in FreeRTOS V8.0.0.
1322 + Rework and simplify the FreeRTOS+FAT SL RAM disk driver.
1324 Miscellaneous updates and maintenance:
1326 + Update the IAR and DS-5/ARM RZ demos to target the official RZ RSK
1327 hardware in place of the previously targeted Renesas internal (not
1328 publicly available) hardware.
1329 + Various other maintenance tasks.
1332 Changes between V8.0.0 and V8.0.1 released 2nd May 2014
1334 + Minor fixes to the event group functionality that was released in V8.0.0.
1335 The 'clear bits from ISR' functionality is now implemented using a
1336 deferred interrupt callback instead of a function, and the 'wait bits' and
1337 'task sync' functions now correctly clear internal control bits before
1338 returning a value in every possible path through the respective functions.
1339 + Ensure the updating of internal control data is protected by a critical
1340 section after a task is deleted or suspended.
1341 + Minor fixes to FreeRTOS+FAT SL - namely seeking beyond the end of a file
1342 when the offset was not a multiple of the sector size.
1343 + Ensure Cortex-A9 system registers are only ever accessed as 32-bit values,
1344 even when only the lest significant byte of the register is implemented.
1348 + Updated the XMC4200 IAR project so it links with version 7.x of the IAR
1351 + Add pcTimerGetName() API function.
1352 + Call _reclaim_reent() when a task is deleted if configUSE_NEWLIB_REENTRANT
1355 Changes between V7.6.0 and V8.0.0 released 19th Feb 2014
1357 https://www.FreeRTOS.org/upgrading-to-FreeRTOS-V8.html
1359 FreeRTOS V8.x.x is a drop-in compatible replacement for FreeRTOS V7.x.x,
1360 although a change to the type used to reference character strings may result
1361 in application code generating a few (easily clearable) compiler warnings
1362 after the upgrade, and an updated typedef naming convention means use of the
1363 old typedef names is now discouraged.
1364 See https://www.FreeRTOS.org/upgrading-to-FreeRTOS-V8.html for full
1367 New features and functionality:
1369 + Event groups - see https://www.FreeRTOS.org/FreeRTOS-Event-Groups.html
1370 + Centralised deferred interrupt processing - see
1371 https://www.FreeRTOS.org/xTimerPendFunctionCallFromISR.html
1375 + Previously, when a task left the Blocked state, a context switch was
1376 performed if the priority of the unblocked task was greater than or equal
1377 to the priority of the Running task. Now a context switch is only
1378 performed if the priority of the unblocked task is greater than the
1379 priority of the Running task.
1380 + New low power tickless demonstration project that targets the ST STM32L
1381 microcontroller - see
1382 https://www.FreeRTOS.org/STM32L-discovery-low-power-tickless-RTOS-demo.html
1383 + Add xPortGetMinimumEverFreeHeapSize() to heap_4.c.
1384 + Small change to the tickless low power implementation on the SAM4L to
1385 ensure the alarm value (compare match value) cannot be set to zero when a
1386 tickless period is exited due to an interrupt originating from a source
1387 other than the RTOS tick.
1388 + Update the GCC/Eclipse Win32 simulator demo to make better use of Eclipse
1389 resource filters and match the functionality of the MSVC equivalent.
1390 + xTaskIsTaskSuspended() is no longer a public function. Use
1391 eTaskGetState() in its place.
1392 + Improved trace macros, including tracing of heap usage.
1393 + Remove one level of indirection when accepting interrupts on the PIC32MZ.
1394 + Add Cortex-A9 GCC port layer.
1395 + Add Xilinx Zynq demo application.
1398 Changes between V7.5.3 and V7.6.0 released 18th November 2013
1400 V7.6.0 changes some behaviour when the co-operative scheduler is used (when
1401 configUSE_PREEMPTION is set to 0). It is important to note that the
1402 behaviour of the pre-emptive scheduler is unchanged - the following
1403 description only applies when configUSE_PREEMPTION is set to 0:
1405 WHEN configUSE_PREEMPTION IS SET TO 0 (which is in a small minority of
1406 cases) a context switch will now only occur when a task places itself into
1407 the Blocked state, or explicitly calls taskYIELD(). This differs from
1408 previous versions, where a context switch would also occur when implicitly
1409 moving a higher priority task out of the Blocked state. For example,
1410 previously, WHEN PREEMPTION WAS TURNED OFF, if task A unblocks task B by
1411 writing to a queue, then the scheduler would switch to the higher priority
1412 task. Now, WHEN PREEMPTION IS TURNED OFF, if task A unblocks task B by
1413 writing to a queue, task B will not start running until task A enters the
1414 Blocked state or task A calls taskYIELD(). [If configUSE_PREEMPTION is not
1415 set to 0, so the normal pre-emptive scheduler is being used, then task B
1416 will start running immediately that it is moved out of the Blocked state].
1420 + Added a port layer and a demo project for the new PIC32MZ architecture.
1421 + Update the PIC32MX port layer to re-introduce some ehb instructions that
1422 were previously removed, add the ability to catch interrupt stack
1423 overflows (previously only task stack overflows were trapped), and also
1424 add the ability to catch an application task incorrectly attempting to
1425 return from its implementing function.
1426 + Make dramatic improvements to the performance of the Win32 simulator port
1428 + Ensure tasks that are blocked indefinitely report their state as Blocked
1429 instead of Suspended.
1430 + Slight improvement to the Cortex-M4F port layers where previously one
1431 register was inadvertently being saved twice.
1432 + Introduce the xSemaphoreCreateBinary() API function to ensure consistency
1433 in the semantics of how each semaphore type is created. It is no longer
1434 recommended to use vSemaphoreCreateBinary() (the version prefixed with a
1435 'v'), although it will remain in the code for backward compatibility.
1436 + Update the Cortex-M0 port layers to allow the scheduler to be started
1437 without using the SVC handler.
1438 + Added a build configuration to the PIC32MX MPLAB X demo project that
1439 targets the PIC32 USB II starter kit. Previously all the build
1440 configurations required the Explorer 16 hardware.
1441 + Some of the standard demo tasks have been updated to ensure they execute
1442 correctly with the updated co-operative scheduling behaviour.
1443 + Added comprehensive demo for the Atmel SAM4E, including use of
1444 FreeRTOS+UDP, FreeRTOS+FAT SL and FreeRTOS+CLI.
1448 + Minor maintenance on FreeRTOS+UDP.
1450 Changes between V7.5.2 and V7.5.3 released October 14 2013
1454 + Prior to V7.5.x yields requested from the tick hook would occur in the
1455 same tick interrupt - revert to that original behaviour.
1456 + New API function uxQueueSpacesAvailable().
1457 + Introduced the prvTaskExitError() function to Cortex-M0, Cortex-M3/4
1458 and Cortex-M4F ports. prvTaskExitError() is used to trap tasks that
1459 attempt to return from their implementing functions (tasks should call
1460 vTaskDelete( NULL ); if they want to exit).
1461 + The Cortex-M0 version of portSET_INTERRUPT_MASK_FROM_ISR and
1462 portCLEAR_INTERRUPT_MASK_FROM_ISR are now fully nestable.
1463 + Improved behaviour and robustness of the default Cortex-M tickless idle
1465 + Add workaround for silicon errata PMU_CM001 in Infineon XMC4000 devices to
1466 all Cortex-M4F ports.
1467 + Add Cortex-M0 port for Keil.
1468 + Updated Cortus port.
1469 + Ensure _impure_ptr is initialised before the scheduler is started.
1470 Previously it was not set until the first context switch.
1474 + Update FreeRTOS+UDP to V1.0.1 - including direct integration of the
1475 FreeRTOS+Nabto task, improvements to the DHCP behaviour, and a correction
1476 to the test that prevents the network event hook being called on the first
1477 network down event. The FreeRTOS+UDP change history is maintained
1479 + Correct the __NVIC_PRIO_BITS setting in the LPC18xx.h header files
1480 provided in the NXP CMSIS library, then update the interrupts used by the
1481 LPC18xx demos accordingly.
1482 + Replace double quotes (") with single quotes (') in FreeRTOS+CLI help
1483 strings to ensure the strings can be used with the JSON descriptions used
1484 in the FreeRTOS+Nabto demos.
1486 Demo and miscellaneous changes:
1488 + Added demo for the Atmel SAMD20 Cortex-M0+. The demo includes
1490 + Added a demo for the Infineon Cortex-M0 that can be built with the IAR
1492 + Updated the Infineon XMC4000 demos for IAR, Keil, GCC and Tasking tools,
1493 with additional build configurations to directly support the XMC4200 and
1494 XMC4400 devices, in addition to the previously supported XMC4500.
1495 + Updated the demo application.
1496 + Added additional trace macros traceMALLOC and traceFREE to track heap
1499 Changes between V7.5.0 and V7.5.2 released July 24 2013
1501 V7.5.2 makes the new Cortex-M vPortCheckInterruptPriority() function
1502 compatible with the STM32 standard peripheral driver library, and adds
1503 an extra critical section to the default low power tickless mode
1504 implementation. Only users of the STM32 peripheral library or the default
1505 tickless implementation need update from version 7.5.0.
1507 Changes between V7.4.2 and V7.5.0 released July 19 2013
1509 V7.5.0 is a major upgrade that includes multiple scheduling and efficiency
1510 improvements, and some new API functions.
1512 Compatibility information for FreeRTOS users:
1513 FreeRTOS V7.5.0 is backward compatible with FreeRTOS V7.4.0 with one
1514 exception; the vTaskList() and vTaskGetRunTimeStats() functions are now
1515 considered legacy, having been replaced by the single uxTaskGetSystemState()
1516 function. configUSE_STATS_FORMATTING_FUNCTIONS must be set to 1 in
1517 FreeRTOSConfig.h for vTaskList() and vTaskGetRunTimeStats() to be
1520 Compatibility information for FreeRTOS port writers:
1521 vTaskIncrementTick() is now called xTaskIncrementTick() (because it now
1526 + Multiple scheduling and efficiency improvements.
1527 + Core kernel files now pass PC-Lint V8 static checking without outputting
1528 any warnings (information on the test conditions will follow).
1532 + uxTaskGetSystemState() https://www.FreeRTOS.org/uxTaskGetSystemState.html
1533 + xQueueOverwrite() https://www.FreeRTOS.org/xQueueOverwrite.html
1534 + xQueueOverwriteFromISR()
1535 + xQueuePeekFromISR()
1537 The following ports and demos, which were previously available separately,
1538 are now incorporated into the main FreeRTOS zip file download:
1541 + ARM Cortex-A9 ARM compiler
1543 + Microsemi SmartFusion2
1545 New FreeRTOSConfig.h settings
1546 https://freertos.org/a00110.html
1548 + configUSE_TIME_SLICING
1549 + configUSE_NEWLIB_REENTRANT
1550 + configUSE_STATS_FORMATTING_FUNCTIONS
1551 + configINCLUDE_APPLICATION_DEFINED_PRIVILEGED_FUNCTIONS
1555 + (MPU port only) The configINCLUDE_APPLICATION_DEFINED_PRIVILEGED_FUNCTIONS
1556 options provides a mechanism that allows application writers to execute
1557 certain functions in privileged mode even when a task is running in user
1559 + Ports that support interrupt nesting now include a configASSERT() that
1560 will trigger if an interrupt safe FreeRTOS function is called from an
1561 interrupt that has a priority designated as above the maximum system/API
1562 call interrupt priority.
1563 + The included FreeRTOS+Trace recorder code has been updated to the latest
1564 version, and the demo applications that use the trace recorder code have
1565 been updated accordingly.
1566 + The FreeRTOS Windows Simulator (MSVC version only) has been updated to
1567 include a new basic 'blinky' build option in addition to the original
1568 comprehensive build option.
1569 + Improve RAM usage efficiency of heap_4.c and heap_2.c.
1570 + Prevent heap_4.c from attempting to free memory blocks that were not
1571 allocated by heap_4.c, or have already been freed.
1572 + As FreeRTOS now comes with FreeRTOS+FAT SL (donated by HCC) the Chan FATfs
1573 files have been removed from FreeRTOS/Demo/Common.
1574 + Fix build error when R4 port is build in co-operative mode.
1575 + Multiple port and demo application maintenance activities.
1577 Changes between V7.4.1 and V7.4.2 released May 1 2013
1579 NOTE: There are no changes in the FreeRTOS kernel between V7.4.1 and V7.4.2
1581 + Added FreeRTOS+FAT SL source code and demo project. The demo project
1582 runs in the FreeRTOS Windows simulator for easy and hardware independent
1583 experimentation and evaluation. See https://www.FreeRTOS.org/fat_sl
1585 Changes between V7.4.0 and V7.4.1 released April 18 2013
1587 + To ensure strict conformance with the spec and ensure compatibility with
1588 future chips data and instruction barrier instructions have been added to
1589 the yield macros of Cortex-M and Cortex-R port layers. For efficiency
1590 the Cortex-M port layer "yield" and "yield" from ISR are now implemented
1591 separately as the barrier instructions are not required in the ISR case.
1592 + Added FreeRTOS+UDP into main download.
1593 + Reorganised the FreeRTOS+ directory so it now matches the FreeRTOS
1594 directory with Source and Demo subdirectories.
1595 + Implemented the Berkeley sockets select() function in FreeRTOS+UDP.
1596 + Changed (unsigned) casting in calls to standard library functions with
1598 + Added the Atmel SAM4L and Renesas RX100 demos that demonstrates the
1599 tickless (tick suppression) low power FreeRTOS features.
1600 + Add a new RL78 IAR demo that targets numerous new RL78 chips and
1602 + Adjusted stack alignment on RX200 ports to ensure an assert was not
1603 falsely triggered when configASSERT() is defined.
1604 + Updated the Cortex_M4F_Infineon_XMC4500_IAR demo to build with the latest
1606 + Corrected header comments in the het.c and het.h files (RM48/TMS570 demo).
1609 Changes between V7.3.0 and V7.4.0 released February 20 2013
1611 + New feature: Queue sets. See:
1612 https://www.FreeRTOS.org/Pend-on-multiple-rtos-objects.html
1613 + Overhauled the default tickless idle mode implementation provided with the
1614 ARM Cortex-M3 port layers.
1615 + Enhanced tickless support in the core kernel code with the introduction of
1616 the configEXPECTED_IDLE_TIME_BEFORE_SLEEP macro and the
1617 eTaskConfirmSleepModeStatus() function.
1618 + Added the QueueSet.c common demo/test file. Several demo applications
1619 have been updated to use the new demo/test tasks.
1620 + Removed reliance on the PLIB libraries from the MPLAB PIC32 port layer and
1622 + Added the FreeRTOS+Trace recorder code to the MSVC Win32 demo.
1623 + Renamed eTaskStateGet() to eTaskGetState() for consistency, and added a
1624 pre-processor macro for backward compatibility with the previous name.
1625 + Updated functions implemented in the core queue.c source file to allow
1626 queue.h to be included from the .c file directly (this prevents compiler
1627 warnings that were generated by some compilers).
1628 + Updated the CCS Cortex-R4 port layer to replace the CLZ assembler function
1629 with the CLZ compiler intrinsic that is provided by the latest versions of
1630 the CCS ARM compiler.
1631 + Updated all heap_x.c implementations to replace the structure that was
1632 used to ensure the start of the heap was aligned with a more portable
1633 direct C code implementation.
1634 + Added support for PIC24 devices that include EDS.
1635 + Minor optimisations to the PIC32 port layer.
1636 + Minor changes to tasks.c that allow the state viewer plug-ins to display
1637 additional information.
1638 + Bug fix: Update prvProcessReceivedCommands() in timers.c to remove an
1639 issue that could occur if the priority of the timer daemon task was set
1640 below the priority of tasks that used timer services.
1641 + Update the FreeRTOS+Trace recorder code to the latest version.
1643 Changes between V7.2.0 and V7.3.0 released October 31 2012
1645 + Added ability to override the default scheduler task selection mechanism
1646 with implementations that make use of architecture specific instructions.
1647 + Added ability to suppress tick interrupts during idle time, and in so
1648 doing, provide the ability to make use of architecture specific low power
1650 + Added the portSUPPRESS_TICKS_AND_SLEEP() macro and vTaskStepTick() helper
1652 + Added the configSYSTICK_CLOCK_HZ configuration constant.
1653 + Reworked the Cortex-M3 and Cortex-M4F port layers for GCC, Keil and IAR to
1654 directly support basic power saving functionality.
1655 + Added hooks to allow basic power saving to be augmented in the application
1656 by making use of chip specific functionality.
1657 + Minor change to allow mutex type semaphores to be used from interrupts
1658 (which would not be a normal usage model for a mutex).
1659 + Change the behaviour of the interrupt safe interrupt mask save and restore
1660 macros in the Cortex-M ports. The save macro now returns the previous
1661 mask value. The restore macro now uses the previous mask value. These
1662 changes are not necessary for the kernel's own implementation, and are
1663 made purely because the macros were being used by application writers.
1664 + Added eTaskStateGet() API function.
1665 + Added port specific optimisations to the PIC32 port layer, and updated the
1666 PIC32 demo applications to make use of this new feature.
1667 + Added port specific optimisations to the Win32 simulator port.
1668 + Added new ports and demo applications for the TI Hercules RM48 and TMS570
1669 safety microcontrollers.
1670 + Added SAM3 demos targeting the ATSAM3S-EK2 and ATSAM3X-EK evaluation
1672 + Updated the PIC32 MPLAB X project to manually set the compiler include
1673 paths instead of using the IDE entry box following reports that the
1674 include paths were somehow being deleted.
1675 + Improved character handling in FreeRTOS+CLI.
1677 Changes between V7.1.1 and V7.2.0 released 14 August 2012
1679 FreeRTOS V7.2.0 is backward compatible with FreeRTOS V7.1.2.
1681 + Added a FreeRTOS+ sub-directory. The directory contains some FreeRTOS+
1682 source code, and example projects that use the FreeRTOS Win32 simulator.
1683 + Added a new example heap allocation implementation (heap_4.c) that
1684 includes memory block coalescence.
1685 + Added a demo that targets the Atmel SAM4S Cortex-M4 based microcontroller.
1686 The demo is preconfigured to build using the free Atmel Studio 6 IDE and
1688 + Added xSemaphoreTakeFromISR() implementation.
1689 + The last parameter in ISR safe FreeRTOS queue and semaphore functions
1690 (xHigherPriorityTaskWoken) is now optional and can be set to NULL if it
1692 + Update the IAR and MSP430X ports to clear all lower power mode bits before
1693 exiting the tick interrupt [bug fix].
1694 + Allow xQueueReset() to be used, even when the queues event lists are not
1696 + Added a vQueueDelete() handler for the FreeRTOS MPU port (this was
1697 previously missing).
1698 + Updated the vPortSVCHandler() functions in the FreeRTOS MPU port layer to
1699 ensure it compiles with the latest ARM GCC compilers from Linaro.
1700 + Updated the prvReadGP() function in the NIOS II port to ensure the compiler
1701 can choose any register for the functions parameter (required at high
1702 compiler optimisation levels).
1703 + Add #error macros into the Keil and IAR Cortex-M ports to ensure they
1704 cannot be built if the user has set configMAX_SYSCALL_INTERRUPT_PRIORITY
1706 + Added comments in the FreeRTOSConfig.h files associated with Cortex-M3 and
1707 Cortex-M4 demos stating that the configMAX_SYSCALL_INTERRUPT_PRIORITY
1708 parameter must not be set to 0.
1709 + Introduce new INCLUDE_xQueueGetMutexHolder configuration constant
1711 + Added two new list handling macros - for internal use only in upcoming new
1713 + Removed all mention of the legacy vTaskStartTrace and ulTaskEndTrace
1714 macros. FreeRTOS+Trace supersedes the legacy trace.
1715 + Added a configASSERT() into the vPortFree() function in heap_1.c as it is
1716 invalid for the function to be called.
1717 + Made the xRxLock and xTxLock members of the queue structure volatile.
1718 This is probably not necessary, and is included as a precautionary
1720 + Modify the assert() that checks to see if the priority passed into an
1721 xTaskCreate() function is within valid bounds to permit the assert to be
1722 used in the FreeRTOS MPU port.
1723 + The software timer service (daemon) task is now created in a way that
1724 to ensure compatibility with FreeRTOS MPU.
1726 Changes between V7.1.0 and V7.1.1 released May 1 2012
1730 The following ports are brand new:
1733 The following ports have been available as separate downloads for a number
1734 of months, but are now included in the main FreeRTOS download.
1737 + Cortex-M4F GCC (with full floating point support)
1742 The following demos are brand new:
1743 + Renesas RX63N RDK (Renesas compiler)
1745 The following demos have been available as separate downloads for a number
1746 of months, but are now included in the main FreeRTOS download.
1747 + NXP LPC1114 GCC/LPCXpresso
1749 + Infineon XMC4500 GCC/Atollic
1750 + Infineon XMC4500 IAR
1751 + Infineon XMC4500 Keil
1752 + Infineon XMC4500 Tasking
1755 Kernel miscellaneous / maintenance:
1757 + Introduced the portSETUP_TCB() macro to remove the requirement for the
1758 Windows simulator to use the traceTASK_CREATE() macro, leaving the trace
1759 macro available for use by FreeRTOS+Trace (https://www.FreeRTOS.org/trace).
1760 + Added a new trace macro, traceMOVE_TASK_TO_READY_STATE(), to allow future
1761 FreeRTOS+Trace versions to provide even more information to users.
1762 + Updated the FreeRTOS MPU port to be correct for changes that were
1763 introduced in FreeRTOS V7.1.0.
1764 + Introduced the xQueueReset() API function.
1765 + Introduced the xSemaphoreGetMutexHolder() API function.
1766 + Tidy up various port implementations to add the static key word where
1767 appropriate, and remove obsolete code.
1768 + Slight change to the initial stack frame given to the RX600 ports to allow
1769 them to be used in the Eclipse based E2Studio IDE without confusing GDB.
1770 + Correct the alignment given to the initial stack of Cortex-M4F tasks.
1771 + Added a NOP following each DINT instruction on MSP430 devices for strict
1772 conformance with the instructions on using DINT.
1773 + Changed the implementation of thread deletes in the Win32 port to prevent
1774 the port making use of the traceTASK_DELETE() trace macros - leaving this
1775 macro free for use by FreeRTOS+Trace.
1776 + Made some benign changes to the RX600 Renesas compiler port layer to
1777 ensure the code can be built to a library without essential code being
1778 removed by the linker.
1779 + Reverted the change in the name of the uxTaskNumber variable made in
1780 V7.1.0 as it broke the IAR plug-in.
1783 Demo miscellaneous / maintenance:
1785 + The command interpreter has now been formally released as FreeRTOS+CLI,
1786 and been moved out of the main FreeRTOS download, to instead be available
1787 from the FreeRTOS+ Ecosystem site https://www.FreeRTOS.org/plus.
1788 + flash_timer.c/h has been added to the list of standard demo tasks. This
1789 performs the same functionality as the flash.c tasks, but using software
1790 timers in place of tasks.
1791 + Upgraded the PIC32 demo as follows: Changes to how the library functions
1792 are called necessitated by the new compiler version, addition of MPLAB X
1793 project with PIC32MX360, PIC32MX460 and PIC32MX795 configurations,
1794 addition of simply blinky demo, updated FreeRTOSConfig.h to include more
1795 parameters, addition of hook function stubs.
1796 + The MSP430X IAR and CCS demos have been updated to ensure the power
1797 settings are correct for the configured CPU frequency.
1798 + Rowley CrossWorks projects have been updated to correct the "multiple
1799 definition of ..." warnings introduced when the toolchain was updated.
1800 + Updated various FreeRTOSConfig.h header files associated with projects
1801 that build with Eclipse to include a #error statement informing the user
1802 that the CreateProjectDirectoryStructure.bat batch file needs to be
1803 executed before the projects can be opened.
1804 + Renamed directories that included "CCS4" in their name to remove the '4'
1805 and instead just be "CCS". This is because the demo was updated and
1806 tested to also work with later Code Composer Studio versions.
1807 + Updated the TCP/IP periodic timer frequency in numerous uIP demos to be
1808 50ms instead of 500ms.
1810 Changes between V7.0.2 and V7.1.0 released December 13 2011
1814 + Cortex-M4F IAR port.
1815 + Cortex-M4F Keil/RVDS port.
1820 + NXP LPC4350 using the Keil MDK, and demonstrated on a Hitex development
1822 + ST STM32F407 using the IAR Embedded Workbench for ARM, and demonstrated on
1823 the IAR STM32F407ZG-SK starter kit.
1824 + Infineon TriCore TC1782, using the GCC compiler, demonstrated on the
1825 TriBoard TC1782 evaluation board.
1826 + Renesas RX630, using the Renesas compiler and HEW, demonstrated on an
1827 RX630 RSK (Renesas Starter Kit).
1829 Miscellaneous / maintenance:
1831 + Removed all calls to printf() from the K60/IAR Kinetis demo so the project
1832 can execute stand alone - without being connected to the debugger.
1833 + Completed the command interpreter framework. Command handlers now receive
1834 the entire command string, giving them direct access to parameters.
1835 Utility functions are provided to check the number of parameters, and
1836 return parameter sub-strings.
1837 + The previously documented fix for the bug in xTaskResumeFromISR() that
1838 effected (only) ports supporting interrupt nesting has now been
1839 incorporated into the main release.
1840 + The portALIGNMENT_ASSERT_pxCurrentTCB() definition has been added to allow
1841 specific ports to skip the second stack alignment check when a task is
1842 created. This is because the second check is not appropriate for some
1843 ports - including the new TriCore port where the checked pointer does not
1844 actually point to a stack.
1845 + The portCLEAN_UP_TCB() macro has been added to allow port specific clean
1846 up when a task is deleted - again this is required by the TriCore port.
1847 + Various other minor changes to ensure warning free builds on a growing
1848 number of microcontroller and toolchain platforms. This includes a
1849 (benign) correction to the prototype of the
1850 vApplicationStackOverflowHook() definition found in lots of recent demos.
1854 + The legacy trace mechanism has been completely removed - it has been
1855 obsolete for the years since the trace macros were introduced. The
1856 configuration constant configUSE_TRACE_FACILITY is now used to optionally
1857 include additional queue and task information. The additional information
1858 is intended to make the trace mechanism more generic, and allow the trace
1859 output to provide more information. When configUSE_TRACE_FACILITY is set
1861 - the queue structure includes an additional member to hold the queue
1862 type, which can be base, mutex, counting semaphore, binary semaphore
1864 - the queue structure includes an additional member to hold a queue
1865 number. A trace tool can set and query the queue number for its own
1866 purposes. The kernel does not use the queue number itself.
1867 - the TCB structure includes an additional member to hold a task number
1868 number. A trace tool can set and query the task number for its own
1869 purposes. The kernel does not use the task number itself.
1870 + Queues and all types of semaphores are now automatically allocated their
1871 type as they are created.
1872 + Added two new trace macros - traceTASK_PRIORITY_INHERIT() and
1873 traskTASK_PRIORITY_DISINHERIT().
1874 + Updated the traceQUEUE_CREATE_FAILED() macro to take a parameter that
1875 indicates the type of queue, mutex, or semaphore that failed to be
1877 + The position from which traceCREATE_MUTEX() is called has been moved from
1878 after the call to xQueueGenericSend() [within the same function] to before
1879 the call. This ensures the trace events occur in the correct order.
1880 + The value passed into tracePRIORITY_SET() has been corrected for the case
1881 where vTaskPrioritySet() is called with a null parameter.
1883 Changes between V7.0.1 and V7.0.2 released September 20 2011
1887 + The official FreeRTOS Renesas RX200 port and demo application have been
1888 incorporated into the main FreeRTOS zip file download.
1889 + The official FreeRTOS Renesas RL78 port and demo application have been
1890 incorporated into the main FreeRTOS zip file download.
1891 + The official FreeRTOS Freescale Kinetis K60 tower demo application has
1892 been incorporated into the main FreeRTOS zip file download. This includes
1893 an embedded web server example.
1894 + A new Microblaze V8 port layer has been created to replace the older, now
1895 deprecated, port layer. The V8 port supports V8.x of the Microblaze IP,
1896 including exceptions, caches, and the floating point unit. A new
1897 Microblaze demo has also been added to demonstrate the new Microblaze V8
1898 port layer. The demo application was created using V13.1 of the Xilinx
1899 EDK, and includes a basic embedded web server that uses lwIP V1.4.0.
1900 + The official FreeRTOS Fujitsu FM3 MB9A310 demo application has been
1901 incorporated into the main FreeRTOS zip file download. Projects are
1902 provided for both the IAR and Keil toolchains.
1907 + xTaskGetIdleTaskHandle() has been added.
1908 + xTaskGetTimerDaemonTaskHandle() has been added.
1909 + pcTaskGetTaskName() has been added.
1910 + vSemaphoreDelete() macro has been added to make it obvious how to delete
1911 a semaphore. In previous versions vQueueDelete() had to be used.
1912 + vTaskCleanUpResources() has been removed. It has been obsolete for a
1914 + portPOINTER_SIZE_TYPE has been introduced to prevent compiler warnings
1915 being generated when the size of a pointer does not match the size of
1916 the stack type. This will (has already) be used in new ports, but will
1917 not be retrofitted to existing ports until the existing port itself is
1920 Other updates and news:
1922 + The core files have all been modified to tighten the coding standard even
1923 further. These are style, not functional changes.
1924 + All ARM7 port layers have been slightly modified to prevent erroneous
1925 assert() failures when tasks are created and configASSERT() is defined.
1926 + All ARM IAR projects have been updated to build with the latest V6.2.x
1927 versions of the IAR Embedded Workbench for ARM tools (EWARM). This was
1928 necessary due to a change in the way EWARM uses the CMSIS libraries.
1929 + The PIC32 port layer has been updated in preparation for V2 of the C32
1931 + The old Virtex-4 Microblaze demo has been marked as deprecated. Please
1932 use the brand new Spartan-6 port and demo in its place.
1933 + The bones of a new generic command interpreter is located in
1934 FreeRTOS/Demo/Common/Utils/CommandInterpreter.c. This is still a work in
1935 progress, and not documented. It is however already in use. It will be
1936 documented in full when the projects that are already using it are
1938 + A couple of new standard demos have been included. First, a version of
1939 flop.c called sp_flop.c. This is similar to flop.c, but uses single
1940 precision floats in place of double precision doubles. This allows the
1941 for testing ports to processors that have only single precision floating
1942 point units, and revert to using emulated calculations whenever a double
1943 is used. Second, comtest_strings.c has been included to allow the test
1944 of UART drivers when an entire string is transmitted at once. The
1945 previous comtest.c only used single character transmission and reception.
1946 + lwIP V1.4.0 is now included in the FreeRTOS/Demo/Common directory, and
1947 used by a couple of new demos.
1949 Changes between V7.0.0 and V7.0.1 released May 13 2011
1951 + Added a Fujitsu FM3 demo application for both the IAR and Keil tool
1953 + Added a SmartFusion demo application for all of the IAR, Keil and
1954 SoftConsole (GCC/Eclipse) tool chains.
1955 + Updated the RX600 port and demo applications to take into account the
1956 different semantics required when using the latest (V1.0.2.0) version of
1957 the Renesas compiler.
1958 + Modified the RX600 Ethernet driver slightly to make it more robust under
1959 heavy load, and updated the uIP handling task to make use of the FreeRTOS
1961 + Slightly changed the PIC32 port layer to move an ehb instruction in line
1962 with the recommendations of the MIPS core manual, and ensure 8 byte stack
1963 alignment is truly always obtained.
1964 + Changed the behaviour when tasks are suspended before the scheduler has
1965 been started. Before, there needed to be at least one task that was not
1966 in the suspended state. This is no longer the case.
1968 Changes between V6.1.1 and V7.0.0 released April 8 2011
1970 FreeRTOS V7.0.0 is backward compatible with FreeRTOS V6.x.x
1974 + Introduced a new software timer implementation.
1975 + Introduced a new common demo application file to exercise the new timer
1977 + Updated the Win32/MSVC simulator project to include the new software timer
1978 demo tasks and software timer tick hook test. Much simpler software timer
1979 demonstrations are included in the demo projects for both of the new ports
1980 (MSP430X with CCS4 and STM32 with TrueStudio).
1981 + Various enhancements to the kernel implementation in tasks.c. These are
1982 transparent to users and do not effect the pre-existing API.
1983 + Added calls to configASSERT() within the kernel code. configASSERT() is
1984 functionally equivalent to the standard C assert() macro, but does not
1985 rely on the compiler providing assert.h.
1989 + Updated the MSP430X IAR port and demo project to include support for the
1990 medium memory model.
1991 + Added a demo project for the MSP430X that targets the MSP430X Discovery
1992 board and uses the Code Composer Studio 4 tools. This demo includes use
1993 of the new software timer implementation.
1994 + Added an STM32F100RB demo project that targets the STM32 Discovery Board
1995 and uses the TrueStudio Eclipse based IDE from Atollic.
1996 + Removed some compiler warnings from the PSoC demo application.
1997 + Updated the PIC32 port layer to ensure the
1998 configMAX_SYSCALL_INTERRUPT_PRIORITY constant works as expected no matter
1999 what its value is (within the valid range set by the microcontroller
2001 + Updated the PIC24, dsPIC and PIC32 projects so they work with the latest
2002 MPLAB compiler versions from Microchip.
2003 + Various cosmetic changes to prepare for a standards compliance statement
2004 that will be published after the software release.
2007 Changes between V6.1.0 and V6.1.1 released January 14 2011
2009 + Added two new Windows simulator ports. One uses the free Microsoft Visual
2010 Studio 2010 express edition, and the other the free MingW/Eclipse
2011 environment. Demo projects are provided for both.
2012 + Added three demo projects for the PSoC 5 (CYAC5588). These are for the
2013 GCC, Keil, and RVDS build tools, and all use the PSoC Creator IDE.
2014 + Added a demo for the low power STM32L152 microcontroller using the IAR
2016 + Added a new port for the MSP430X core using the IAR Embedded Workbench.
2017 + Updated all the RX62N demo projects that target the Renesas Demonstration
2018 Kit (RDK) to take into account the reversed LED wiring on later hardware
2019 revisions, and the new J-Link debug interface DLL.
2020 + Updated all the RX62N demo projects so the IO page served by the example
2021 embedded web server works with all web browsers.
2022 + Updated the Red Suite projects to work with the up coming Red Suite
2023 release, and to use a more recent version of the CMSIS libraries.
2024 + Added the traceTAKE_MUTEX_RECURSIVE_FAILED() trace macro.
2025 + Removed the (pointless) parameter from the traceTASK_CREATE_FAILED()
2027 + Introduced the portALT_GET_RUN_TIME_COUNTER_VALUE() macro to compliment
2028 the already existing portGET_RUN_TIME_COUNTER_VALUE(). This allows for
2029 more flexibility in how the time base for the run time statistics feature
2031 + Added a "cpsie i" instruction before the "svc 0" instruction used to start
2032 the scheduler in each of the Cortex M3 ports. This is to ensure that
2033 interrupts are globally enabled prior to the "svc 0" instruction being
2034 executed in cases where interrupts are left disabled by the C start up
2036 + Slight optimisation in the run time stats calculation.
2038 Changes between V6.0.5 and V6.1.0 released October 6 2010
2040 + Added xTaskGetTickCountFromISR() function.
2041 + Modified vTaskSuspend() to allow tasks that have just been created to be
2042 immediately suspended even when the kernel has not been started. This
2043 allows them to effectively start in the Suspended state - a feature that
2044 has been asked for on numerous occasions to assist with initialisation
2046 + Added ports for the Renesas RX62N using IAR, GCC and Renesas tool suites.
2047 + Added a STM32F103 demo application that uses the Rowley tools.
2048 + Under specific conditions xFreeBytesRemaining within heap_2.c could end up
2049 with an incorrect value. This has been fixed.
2050 + xTaskCreateGeneric() has a parameter that can be used to pass the handle
2051 of the task just created out to the calling task. The assignment to this
2052 parameter has been moved to ensure it is assigned prior to the newly
2053 created having any possibility of executing. This takes into account the
2054 case where the assignment is made to a global variable that is accessed by
2055 the newly created task.
2056 + Fixed some build time compiler warnings in various FreeTCPIP (based on
2058 + Fixed some build time compiler warnings in Demo/Common/Minimal/IntQueue.c.
2060 Changes between V6.0.4 and V6.0.5 released May 17 2010
2062 + Added port and demo application for the Cortus APS3 processor.
2064 Changes between V6.0.3 and V6.0.4 released March 14 2010
2066 + All the contributed files that were located in the Demo/Unsupported_Demos
2067 directory have been removed. These files are instead now available in the
2068 new Community Contributions section of the FreeRTOS website. See
2069 https://www.FreeRTOS.org/RTOS-contributed-ports.html
2070 + The project file located in the Demo/CORTEX_STM32F107_GCC_Rowley directory
2071 has been upgraded to use V2.x of the Rowley Crossworks STM32 support
2073 + An initial Energy Micro EFM32 demo has been included. This will be
2074 updated over the coming months to make better use of the low power modes
2077 Changes between V6.0.2 and V6.0.3 released February 26 2010
2079 + SuperH SH7216 (SH2A-FPU) port and demo application added.
2080 + Slight modification made to the default implementation of
2081 pvPortMallocAligned() and vPortFreeAligned() macros so by default they
2082 just call pvPortMalloc() and vPortFree(). The macros are only needed to
2083 be defined when a memory protection unit (MPU) is being used - and then
2084 only depending on other configuration settings.
2086 Changes between V6.0.1 and V6.0.2 released January 9th 2010
2088 + Changed all GCC ARM 7 ports to use 0 as the SWI instruction parameter.
2089 Previously the parameter was blank and therefore only an implicit 0 but
2090 newer GCC releases do not permit this.
2091 + Updated IAR SAM7S and SAM7X ports to work with IAR V5.40.
2092 + Changed the stack alignment requirement for PIC32 from 4 bytes to 8 bytes.
2093 + Updated prvListTaskWithinSingleList() is it works on processors where the
2094 stack grows up from low memory.
2095 + Corrected some comments.
2096 + Updated the startup file for the RVDS LPC21xx demo.
2098 Changes between V6.0.0 and V6.0.1 released November 15th 2009
2100 + Altered pxPortInitialiseStack() for all Cortex-M3 ports to ensure the
2101 stack pointer is where the compiler expects it to be when a task first
2104 The following minor changes only effect the Cortex-M3 MPU port:
2106 + portRESET_PRIVILEGE() assembly macro updated to include a clobber list.
2107 + Added prototypes for all the privileged function wrappers to ensure no
2108 compile time warnings are generated no matter what the warning level
2110 + Corrected the name of portSVC_prvRaisePrivilege to
2111 portSVC_RAISE_PRIVILEGE.
2112 + Added conditional compilation into xTaskGenericCreate() to prevent some
2113 compilers issuing warnings when portPRIVILEGE_BIT is defined as zero.
2116 Changes between V5.4.2 and V6.0.0 released October 16th 2009
2118 FreeRTOS V6 is backward compatible with FreeRTOS V5.x.
2122 + FreeRTOS V6 is the first version to include memory protection unit (MPU)
2123 support. Two ports now exist for the Cortex M3, the standard FreeRTOS
2124 which does not include MPU support, and FreeRTOS-MPU which does.
2125 + xTaskCreateRestricted() and vTaskAllocateMPURegions() API functions added
2126 in support of FreeRTOS-MPU.
2127 + Wording for the GPL exception has been (hopefully) clarified. Also the
2128 license.txt file included in the download has been fixed (the previous
2129 version contained some corruption).
2133 + New API function xPortGetFreeHeapSize() added to heap_1.c and heap_2.c.
2134 + ARM7 GCC demo interrupt service routines wrappers have been modified to
2135 call the C portion using an __asm statement. This prevents the function
2136 call being inlined at higher optimisation levels.
2137 + ARM7 ports now automatically set the THUMB bit if necessary when
2138 setting up the initial stack of a task - removing the need for
2139 THUMB_INTERWORK to be defined. This also allows THUMB mode and ARM mode
2140 tasks to be mixed more easily.
2141 + All ARM7/9 ports now have portBYTE_ALIGNMENT set to 8 by default.
2142 + Various demo application project files have been updated to be up to date
2143 with the latest IDE versions.
2144 + The linker scripts used with command line GCC demos have been updated to
2145 include an eh_frame section to allow their use with the latest Yagarto
2146 release. Likewise the demo makefiles have been updated to include
2147 command line options to reduce or eliminate the eh_frame section all
2149 + The definition of portBYTE_ALIGNMENT_MASK has been moved out of the
2150 various memory allocation files and into the common portable.h header
2152 + Removed unnecessary use of portLONG, portSHORT and portCHAR.
2153 + Added LM3Sxxxx demo for Rowley CrossWorks.
2154 + Posix simulator has been upgraded - see the corresponding WEB page on the
2158 Changes between V5.4.1 and V5.4.2 released August 9th 2009
2160 + Added a new port and demo app for the Altera Nios2 soft core.
2161 + Added LPC1768 demo for IAR.
2162 + Added a USB CDC demo to all LPC1768 demos (Code Red, CrossWorks and IAR).
2163 + Changed clock frequency of LPC1768 demos to 99MHz.
2165 Changes between V5.4.0 and V5.4.1 released July 25th 2009
2167 + New hook function added. vApplicationMallocFailedHook() is (optionally)
2168 called if pvPortMalloc() returns NULL.
2169 + Additional casting added to xTaskCheckForTimeOut(). This prevents
2170 problems that can arise should configUSE_16_BIT_TICKS be set to 1 on a
2171 32 bit architecture (which would probably be a mistake, anyway).
2172 + Corrected the parameter passed to NVIC_SetPriority() to set the MAC
2173 interrupt priority in both LPC1768 demos.
2174 + Decreased the default setting of configMINIMAL_STACK_SIZE in the PIC32
2175 demo application to ensure the heap space was not completely consumed
2176 before the scheduler was started.
2178 Changes between V5.3.1 and V5.4.0 released July 13th 2009
2180 + Added Virtex5 / PPC440 port and demos.
2181 + Replaced the LPC1766 Red Suite demo with an LPC1768 Red Suite demo. The
2182 original demo was configured to use engineering samples of the CPU. The
2183 new demo has an improved Ethernet driver.
2184 + Added LPC1768 Rowley demo with zero copy Ethernet driver.
2185 + Reworked byte alignment code to ensure 8 byte alignment works correctly.
2186 + Set configUSE_16_BIT_TICKS to 0 in the PPC405 demo projects.
2187 + Changed the initial stack setup for the PPC405 to ensure the small data
2188 area pointers are setup correctly.
2190 Changes between V5.3.0 and V5.3.1 released June 21st 2009
2192 + Added ColdFire V1 MCF51CN128 port and WEB server demo.
2193 + Added STM32 Connectivity Line STM32107 Cortex M3 WEB server demo.
2194 + Changed the Cortex M3 port.c asm statements to __asm so it can be
2195 compiled using Rowley CrossWorks V2 in its default configuration.
2196 + Updated the Posix/Linux simulator contributed port.
2198 Changes between V5.2.0 and V5.3.0 released June 1st 2009
2202 + Added new (optional) feature that gathers statistics on the amount of CPU
2203 time used by each task.
2204 + Added a new demo application for the Atmel AT91SAM3U Cortex-M3 based
2206 + Added a new demo application for the NXP LPC1766 Cortex-M3 based
2208 + Added a contributed port/demo that allows FreeRTOS to be 'simulated' in a
2212 + Updated the Stellaris uIP WEB server demos to include the new run time
2213 statistics gathering feature - and include a served WEB page that
2214 presents the information in a tabular format.
2215 + Added in the lwIP port layer for the Coldfire MCF52259.
2216 + Updated the CrossWorks LPC2368 WEB server to include an image in the
2218 + Changed some of the timing in the initialisation of the LPC2368 MAC to
2219 permit its use on all part revisions.
2220 + Minor modifications to the core uIP code to remove some compiler warnings.
2221 + Added xTaskGetApplicationTaskTag() function and updated the OpenWatcom
2222 demo to make use of the new function.
2223 + Added contributed demos for AVR32 AP7000, STM32 Primer 2 and STM32 using
2225 + Heap_1.c and Heap_2.c used to define structures for the purpose of data
2226 alignment. These have been converted to unions to save a few bytes of
2227 RAM that would otherwise be wasted.
2228 + Remove the call to strncpy() used to copy the task name into the TCB when
2229 the maximum task name is configured to be 1 byte long.
2231 Changes between V5.1.2 and V5.2.0 released March 14th 2009
2233 + Optimised the queue send and receive functions (also used by semaphores).
2234 + Replaced the standard critical sections used to protect BIOS calls in the
2235 PC port to instead use scheduler locks. This is because the BIOS calls
2236 always return with interrupts enabled.
2237 + Corrected unclosed comments in boot.s.
2239 Changes between V5.1.1 and V5.1.2 released February 9th 2009
2241 + Added NEC V850ES port and demo.
2242 + Added NEC 78K0R port and demo.
2243 + Added MCF52259 port and demo.
2244 + Added the AT91SAM9XE port and demo.
2245 + Updated the MCF52233 FEC driver to work around a silicon bug that
2246 prevents the part auto negotiating some network parameters.
2247 + Minor modifications to the MCF52233 makefile to permit it to be used
2249 + Updated the STM32 primer files to allow them to be built with the latest
2250 version of the RIDE tools.
2251 + Updated the threads.js Java script used for kernel aware debugging in
2252 the Rowley CrossWorks IDE.
2255 Changes between V5.1.0 and V5.1.1 released November 20, 2008
2257 + Added Coldfire MCF52233 WEB server demo using GCC and Eclipse.
2258 + Added IAR MSP430 port and demo.
2259 + Corrected several compiler time issues that had crept in as tool versions
2261 + Included FreeRTOS-uIP - a faster uIP. This is not yet complete.
2263 Changes between V5.0.4 and V5.1.0 released October 24, 2008
2265 + Added a new port and demo application for the ColdFire V2 core using the
2266 CodeWarrior development tools.
2267 + Replaced the ARM7 demo that used the old (and now no longer supported)
2268 Keil compiler with a new port that uses the new Keil/RVDS combo.
2269 + Stack overflow checking now works for stacks that grow up from low
2270 memory (PIC24 and dsPIC).
2271 + BUG FIX - set the PIC32 definition of portSTACK_GROWTH to the correct
2273 + MSP430 port layers have been updated to permit tasks to place the
2274 microcontroller into power down modes 1 to 3. The demo applications have
2275 likewise been updated to demonstrate the new feature.
2276 + Replaced the two separate MSP430/Rowley port layers with a single and more
2278 + Added more contributed ports, including ports for NEC and SAM9
2280 + Changed the linker script used in the LPC2368 Eclipse demo.
2282 Changes between V5.0.3 and V5.0.4 released September 22, 2008
2284 + Completely re-written port for ColdFire GCC.
2285 + Bug fix: All Cortex M3 ports have a minor change to the code that sets
2286 the pending interrupt.
2287 + Some header files require that FreeRTOS.h be included prior to their
2288 inclusion. #error message have been added to all such header file
2289 informing users to the cause of the compilation error should the headers
2290 not be included in the correct order.
2292 Changes between V5.0.2 and V5.0.3 released July 31, 2008
2294 Changes relating to the Cortex M3:
2296 + Added configMAX_SYSCALL_INTERRUPT_PRIORITY usage to all the Cortex M3
2297 ports and demos. See the port documentation pages on the FreeRTOS.org
2298 WEB site for full usage information.
2299 + Improved efficiency of Cortex M3 port even further.
2300 + Ensure the Cortex M3 port works no matter where the vector table is
2302 + Added the IntQTimer demo/test tasks to a demo project for each CM3 port
2303 (Keil, GCC and IAR) to test the new configMAX_SYSCALL_INTERRUPT_PRIORITY
2305 + Added the mainINCLUDE_WEB_SERVER definition to the LM3SXXXX IAR and Keil
2306 projects to allow the WEB server to be conditionally excluded from the
2307 build and therefore allow use of the KickStart (code size limited)
2312 + Moved the PIC24 and dsPIC versions of vPortYield() from the C file to
2313 an assembly file to allow use with all MPLAB compiler versions. This also
2314 allows the omit-frame-pointer optimisation to be turned off.
2316 Changes between V5.0.0 and V5.0.2 released May 30, 2008
2318 + Updated the PIC32 port to allow queue API calls to be used from
2319 interrupts above the kernel interrupt priority, and to allow full
2320 interrupt nesting. Task stack usages has also been reduced.
2321 + Added a new PowerPC port that demonstrates how the trace macros can be
2322 used to allow the use of a floating point co-processor. The
2323 traceTASK_SWITCHED_OUT() and traceTASK_SWITCHED_INT() macros are used to
2324 save and restore the floating point context respectively for those tasks
2325 that actually use floating point operations.
2326 + BUG FIX: The first PPC405 port contained a bug in that it did not leave
2327 adequate space above the stack for the backchain to be saved when a task
2328 started to execute for the first time.
2329 + Updated queue.c to add in the means to allow interrupt nesting and for
2330 queue API functions to be called from interrupts that have a priority
2331 above the kernel priority. This is only supported on PIC32 ports thus
2333 + Fixed the compiler warnings that were generated when the latest version
2335 + Remove all inline usage of 'inline' from the core kernel code.
2336 + Added the queue registry feature. The queue registry is provided as a
2337 means for kernel aware debuggers to locate queue definitions. It has no
2338 purpose unless you are using a kernel aware debugger. The queue registry
2339 will only be used when configQUEUE_REGISTRY_SIZE is greater than zero.
2340 + Added the ST Cortex-M3 drivers into the Demo/Common/Drivers directory to
2341 prevent them from having to be included in multiple demos.
2342 + Added a Keil STM32 demo application.
2343 + Changed the blocktim.c test files as it is no longer legitimate for all
2344 ports to call queue API functions from within a critical section.
2345 + Added the IntQueue.c test file to test the calling of queue API functions
2346 from different interrupt priority levels, and test interrupt nesting.
2348 Changes between V5.0.0 and V5.0.1
2350 + V5.0.1 was a customer specific release.
2352 Changes between V4.8.0 and V5.0.0 released April 15, 2008
2354 *** VERY IMPORTANT INFORMATION ON UPGRADING TO FREERTOS.ORG V5.0.0 ***
2356 The parameters to the functions xQueueSendFromISR(), xQueueSendToFrontFromISR(),
2357 xQueueSendToBackFromISR() and xSemaphoreGiveFromISR() have changed. You must
2358 update all calls to these functions to use the new calling convention! Your
2359 compiler might not issue any type mismatch warnings!
2364 + Support added for the new Luminary Micro LM3S3768 and LM3S3748 Cortex-M3
2366 + New task hook feature added.
2367 + PowerPC demo updated to use version 10.1 of the Xilinx EDK.
2368 + Efficiency gains within the PIC32 port layer.
2370 Changes between V4.7.2 and V4.8.0 released March 26 2008
2372 + Added a Virtex4 PowerPC 405 port and demo application.
2373 + Added optional stack overflow checking and new
2374 uxTaskGetStackHighWaterMark() function.
2375 + Added new xQueueIsQueueEmptyFromISR(), xQueueIsQueueFullFromISR() and
2376 uxQueueMessagesWaitingFromISR() API functions.
2377 + Efficiency improvements to the Cortex-M3 port layer. NOTE: This
2378 requires that an SVC handler be installed in the application.
2379 + Efficiency improvements to the queue send and receive functions.
2380 + Added new trace macros. These are application definable to provide
2381 a flexible trace facility.
2382 + Implemented the configKERNEL_INTERRUPT_PRIORITY within the Keil Cortex
2383 M3 port layer (bringing it up to the same standard as the IAR and GCC
2385 + Ports that used the arm-stellaris-eabi-gcc tools have been converted to
2386 use the arm-non-eabi-gcc tools.
2388 Changes between V4.7.1 and V4.7.2 released February 21, 2008
2390 + Added Fujitsu MB91460 port and demo.
2391 + Added Fujitsu MB96340 port and demo.
2392 + Tidied up the capitalisation of include files to facilitate builds on
2394 + Removed some redundant casting that was generating warnings - but was
2395 included to remove warnings on other compilers.
2397 Changes between V4.7.0 and V4.7.1 released February 3, 2008
2399 + Updated all IAR ARM projects to use V5.11 of the IAR Embedded Workbench
2401 + Introduced recursive semaphore feature.
2402 + Updated LPC2368 demos to take into account silicon bugs in old chip
2404 + Updated STR9 uIP port to manually set the net mask and gateway addresses.
2405 + Updating demos to allow more to run with the co-operative scheduler.
2406 + Fixed co-operative scheduler behaviour upon the occurrence of a tick
2407 interrupt while the scheduler was suspended.
2408 + Updated documentation contained within semphr.h.
2409 + ARM7 GCC ports no longer use the IRQ attribute.
2411 Changes between V4.6.1 and V4.7.0 released December 6, 2007
2413 + Introduced the counting semaphore macros and demo source files. The
2414 Open Watcom PC project has been updated to include the new demo. See
2415 the online documentation for more information.
2416 + Introduced the 'alternative' queue handling API and demo source files.
2417 The Open Watcom PC project has been updated to include the new demo
2418 source files. See the online documentation for more information.
2419 + Added AT91SAM7X Eclipse demo project.
2420 + Added the STM32 primer demo project for the GCC compiler and Ride IDE.
2421 + Removed the .lock files that were mistakenly included in the V4.6.1
2424 Changes between V4.6.0 and V4.6.1 released November 5 2007
2426 + Added support for the MIPS M4K based PIC32.
2427 + Added 'extern "C"' to all the header files to facilitate use with C++.
2429 Changes between V4.5.0 and V4.6.0 released October 28 2007
2431 + Changed the method used to force a context switch within an ISR for the
2432 ARM7/9 GCC ports only. The portENTER_SWITCHING_ISR() and
2433 portEXIT_SWITCHING_ISR() macros are no longer supported. This is to
2434 ensure correct behaviour no matter which GCC version is used, with or
2435 without the -fomit-frame-pointer option, and at all optimisation levels.
2436 + Corrected the prototype for xQueueGenericSend() within queue.h.
2438 Changes between V4.4.0 and V4.5.0 released September 17 2007
2440 + Added the xQueueSendToFront(), xQueueSendToBack() and xQueuePeek()
2441 functionality. These should now be used in preference to the old
2442 xQueueSend() function - which is maintained for backward compatibility.
2443 + Added Mutex functionality. The behaviour of mutexes is subtly different
2444 to the already existing binary semaphores as mutexes automatically
2445 include a priority inheritance mechanism.
2446 + Added the GenQTest.c and QPeek.c to test and demonstrate the behaviour
2447 of the new functionality.
2448 + Updated the LM3Sxxxx and PC ports to include the new GenQTest.c and
2450 + Updated the GCC port for the Cortex M3 to include the
2451 configKERNEL_INTERRUPT_PRIORITY functionality. This was previously only
2452 included in the IAR port.
2453 + Optimised the GCC and IAR port layer code - specifically the context
2455 + Consolidated the LM3Sxxxx EK demos for all development tools into a
2456 single project that automatically detects which version of the EK the
2457 application is executing on.
2458 + Added Eclipse support for LM3Sxxxx evaluation kits.
2459 + Added Eclipse support for the Keil LPC2368 evaluation kit.
2460 + Added the Demo/Drivers directory to hold code that is common to multiple
2461 demo application projects.
2462 + Included some minor bug fixes in the uIP 1.0 code.
2463 + Added an lwIP demo for the STR9 - thanks ST for assistance.
2464 + Updated the AVR32 port to ensure correct behaviour with full compiler
2466 + Included binaries for OpenOCD FTDI and parallel port interfaces.
2468 Changes between V4.4.0 and V4.3.1 released July 31, 2007
2470 + Added AVR32 UC3B demo application.
2471 + Updated AVR32 UC3A port and demo applications.
2472 + Added IAR lwIP demo for AVR32 UC3A.
2473 + Updated listGET_OWNER_OF_NEXT_ENTRY() to assist compiler optimisation
2474 (thanks Niu Yong for making the suggestion).
2475 + Added xTaskGetSchedulerState() API function.
2476 + BUG FIX: Corrected behaviour when tasks that are blocked indefinitely
2477 have their block time adjusted (within xQueueSend() and xQueueReceive()),
2478 and are the subject of a call the vTaskResume() when they are not
2479 actually in the Suspended state (thanks Dan Searles for reporting the
2483 Changes between V4.3.0 and V4.3.1 released June 11, 2007
2485 + Added STMicroelectronics STM32 Cortex-M3 demo application.
2486 + Updated ustdlib.c for the GCC LM3S6965 demo.
2488 Changes between V4.2.1 and V4.3.0 released June 5, 2007
2490 + Introduced configKERNEL_INTERRUPT_PRIORITY to the IAR Cortex-M3, PIC24
2491 and dsPIC ports. See the LM3S6965 and PIC24 demo application
2492 documentation pages for more information.
2493 + Updated the PIC24 and dsPIC demos to build with V3.0 of the PIC30 GCC
2494 tools, and changed the demo applications.
2495 + Added demos for the new Ethernet and CAN enabled Luminary Micro Stellaris
2497 + Corrected bug in uIP the demos that prevented frames of approximately 1480
2498 bytes and over from being transmitted.
2499 + Included the LPC2368/uIP/Rowley demo into the main FreeRTOS.org
2501 + Update to WizC PIC18 port to permit its use with version 14 of the
2502 compiler. Thanks Marcel!
2504 Changes between V4.2.1 and V4.2.0 released April 2, 2007
2506 + Added AVR32 AT32UC3A ports for GCC and IAR.
2507 + Added -fomit-frame-pointer option to lwIP SAM7X demo makefile.
2508 + Moved location of call to LCD_Init() in STR9 demo to ensure it is only
2509 called after the scheduler has been started.
2511 Changes between V4.1.3 and V4.2.0 released February 8, 2007
2513 + Changes to both task.c and queue.c as a result of testing performed on
2514 the SafeRTOS code base.
2515 + Added Cortex-M3 LM3S811 demos for GCC and IAR tools.
2517 Changes between V4.1.2 and V4.1.3 released November 19, 2006
2519 + Added STR750 ARM7 port using the Raisonance RIDE/GCC tools.
2520 + Added -fomit-frame-pointer option to Rowley ARM7 demos as work around
2521 to GCC bug at some optimisation levels.
2522 + Altered the way the heap is defined in the LM3S811 Keil demo to prevent
2523 the RAM usage from counting toward the code size limit calculation.
2524 + CO-ROUTINE BUG FIX: Removed the call to prvIsQueueEmpty from within
2525 xQueueCRReceive as it exited with interrupts enabled. Thanks Paul Katz.
2526 + Tasks that block on events with a timeout of portMAX_DELAY are now
2527 blocked indefinitely if configINCLUDE_vTaskSuspend is defined.
2528 Previously portMAX_DELAY was just the longest block time possible. This
2529 is still the case if configINCLUDE_vTaskSuspend is not defined.
2530 + Minor changes to some demo application files.
2532 Changes between V4.1.1 and V4.1.2 released October 21, 2006
2534 + Added 16bit PIC ports and demos.
2535 + Added STR750 port and demo.
2538 Changes between V4.1.0 and V4.1.1 released September 24, 2006
2540 + Added the Luminary Micro Stellaris LM3S811 demo application.
2542 Changes between V4.0.5 and V4.1.0 released August 28, 2006
2544 + Prior to V4.1.0, under certain documented circumstances, it was possible
2545 for xQueueSend() and xQueueReceive() to return without having completed
2546 and without their block time expiring. The block time effectively
2547 stated a maximum block time, and the return value of the function needed
2548 to be checked to determine the reason for returning. This is no longer
2549 the case as the functions will only return once the block time has
2550 expired or they are able to complete their operation. It is therefore no
2551 longer necessary to wrap calls within loops.
2552 + Changed the critical section handling in the IAR AVR port to correct the
2553 behaviour when used with later compiler versions.
2554 + Added the LPC2138 CrossWorks demo into the zip file. Previously this was
2555 only available as a separate download.
2556 + Modified the AVR demo applications to demonstrate the use of co-routines.
2558 Changes between V4.0.4 and V4.0.5 released August 13, 2006
2560 + Introduced API function xTaskResumeFromISR(). Same functionality as
2561 xTaskResume(), but can be called from within an interrupt service routine.
2562 + Optimised vListInsert() in the case when the wake time is the maximum
2564 + Bug fix: The 'value' of the event list item is updated when the priority
2565 of a task is changed. Previously only the priority of the TCB itself was
2567 + vTaskPrioritySet() and vTaskResume() no longer use the event list item.
2568 This has not been necessary since V4.0.1 when the xMissedYield handling
2570 + Lowered the PCLK setting on the ARM9 STR9 demo from 96MHz to 48MHz.
2571 + When ending the scheduler - do not try to attempt a context switch when
2572 deleting the current task.
2573 + SAM7X EMAC drivers: Corrected the Rx frame length mask when obtaining
2574 the length from the rx descriptor.
2577 Changes between V4.0.3 and V4.0.4 released June 22, 2006
2579 + Added a port and demo application for the STR9 ARM9 based processors from
2581 + Slight optimisation to the vTaskPrioritySet() function.
2582 + Included the latest uIP version (1.0) in the demo/common/ethernet
2585 Changes between V4.0.2 and V4.0.3 released June 7, 2006
2587 + Added a port and demo application for the Cortex-M3 target using the IAR
2589 + The ARM Cortex-m3 Rowley projects have been updated to use V1.6 of the
2591 + The heap size defined for the lwIP Rowley demo has been reduced so that
2592 the project will link correctly when using the command line GCC tools
2593 also. The makefile has also been modified to allow debugging.
2594 + The lwIP Rowley demo not includes a 'kernel aware' debug window.
2595 + The uIP Rowley project has been updated to build with V1.6 of CrossWorks.
2596 + The second set of tasks in the blockQ demo were created the wrong way
2597 around (inconsistent to the description in the file). This has been
2600 Changes between V4.0.1 and V4.0.2 released May 28, 2006
2602 + Port and demo application added for the Tern Ethernet Engine controller.
2603 + Port and demo application added for MC9S12 using GCC, thanks to
2604 Jefferson "imajeff" Smith.
2605 + The function vTaskList() now suspends the scheduler rather than disabling
2606 interrupts during the creation of the task list.
2607 + Allow a task to delete itself by passing in its own handle. Previously
2608 this could only be done by passing in NULL.
2609 + Corrected the value passed to the WDG_PeriodValueConfig() library
2610 function in the STR71x demo.
2611 + The tick hook function is now called only within a tick isr. Previously
2612 it was also called when the tick function was called during the scheduler
2614 + The EMAC driver in the SAM7X lwIP demo has been made more robust as per
2615 the thread: https://sourceforge.net/forum/message.php?msg_id=3714405
2616 + In the PC ports: Add function prvSetTickFrequencyDefault() to set the
2617 DOS tick back to its proper value when the scheduler exits. Thanks
2619 + In the Borland x86 ports there was a mistake in the portFIRST_CONTEXT
2620 macro where the BP register was not popped from the stack correctly. The
2621 BP value would never get used so this did not cause a problem, but it has
2622 been corrected all the same.
2625 Changes between V4.0.0 and V4.0.1 released April 7 2006
2627 + Improved the ARM CORTEX M3 ports so they now only have to service
2629 + Added a Luminary Micro port and demo for use with Rowley CrossWorks.
2630 + Added the xMissedYield handling to tasks.c.
2632 Changes between V3.2.4 and V4.0.0
2636 + Added new RTOS port for Luminary Micros ARM CORTEX M3 microcontrollers.
2637 + Added new co-routine functionality.
2639 Other kernel changes:
2641 + An optional tick hook call is now included in the tick function.
2642 + Introduced the xMiniListItem structure and removed the list pxHead
2643 member in order to reduce RAM usage.
2644 + Added the following definitions to the FreeRTOSConfig.h file included
2647 configUSE_CO_ROUTINES
2648 configMAX_CO_ROUTINE_PRIORITIES
2649 + The volatile qualification has been changed on the list members to allow
2650 the task.c code to be tidied up a bit.
2651 + The scheduler can now be started even if no tasks have been created!
2652 This is to allow co-routines to run when there are no tasks.
2653 + A task being woken by an event will now preempt the currently running task
2654 even if its priority is only equal to the currently running task.
2656 Port and demo application changes:
2658 + Updated the WinAVR demo to compile with the latest version of WinAVR
2659 with no warnings generated.
2660 + Changed the WinAVR makefile to make chars signed - needed for the
2661 co-routine code if BaseType_t is set to char.
2662 + Added new demo application file crflash.c. This demonstrates co-routine
2663 functionality including passing data between co-routines.
2664 + Added new demo application file crhook.c. This demonstrates co-routine
2665 and tick hook functionality including passing data between and ISR and
2667 + Some NOP's were missing following stmdb{}^ instructions in various ARM7
2668 ports. These have been added.
2669 + Updated the Open Watcom PC demo project to include the crflash and crhook
2670 demo co-routines as an example of their use.
2671 + Updated the H8S demo to compile with the latest version of GCC.
2672 + Updated the SAM7X EMAC drivers to take into account the hardware errata
2673 regarding lost packets.
2674 + Changed the default MAC address used by some WEB server demos as the
2675 original addresses used was not liked by some routers.
2676 + Modified the SAM7X/IAR startup code slightly to prevent it hanging on
2677 some systems when the code is executed using a j-link debugger. The
2678 j-link macro file configures the PLL before the code executes so
2679 attempting to configure it again in the startup code was causing a
2680 problem for some user. Now a check is performed first to see if the
2681 PLL is already set up.
2682 + GCC port now contain all assembler code in a single asm block rather than
2683 individual blocks as before.
2684 + GCC LPC2000 code now explicitly uses R0 rather than letting the assembler
2685 choose the register to use as a temporary register during the context
2687 + Added portNOP() macro.
2688 + The compare match load value on LPC2000 ports now has 1 added to correct
2690 + The minimal stack depth has been increased slightly on the WIZC PIC18
2693 Changes between V3.2.3 and V3.2.4
2695 + Modified the GCC ARM7 port layer to allow use with GCC V4.0.0 and above.
2696 Many thanks to Glen Biagioni for the provided update.
2697 + Added a new Microblaze port and demo application.
2698 + Modified the SAM7X EMAC demo to default to use the MII interface rather
2699 than the RMII interface.
2700 + Modified the startup sequence of the SAM7X demo slightly to allow the
2701 EMAC longer to auto negotiate.
2703 Changes between V3.2.2 and V3.2.3
2705 + Added MII interface support to the SAM7X EMAC peripheral driver.
2706 Previously versions worked with the RMII interface only.
2707 + Added command line GCC support to the SAM7X lwIP demo. Previously the
2708 project could only be built using the CrossWorks IDE. Modifications to
2709 this end include the addition of a standard makefile and linker script to
2710 the download, and some adjustments to the stacks allocated to each task.
2711 + Changed the page returned by the lwIP WEB server demo to display the
2712 task status table rather than the TCP/IP statistics.
2713 + Corrected the capitalisation of some header file includes and makefile
2714 dependencies to facilitate use on Linux host computers.
2715 + The various LPC2000 ports had a mistake in the timer setup where the
2716 prescale value was written to T0_PC instead of T0_PR. This would have
2717 no effect unless a prescale value was actually required. This has been
2720 Changes between V3.2.1 and V3.2.2 - Released 23 September, 2005
2722 + Added an IAR port for the Philips LPC2129
2723 + The Atmel ARM7 IAR demo project files are now saved in the IAR Embedded
2724 Workbench V4.30a format.
2725 + Updated the J-Link macro file included with the SAM7X uIP demo project
2726 to allow the demo board to be reset over the J-Link.
2728 Changes between V3.2.0 and V3.2.1 - Released 1 September, 2005
2730 + Added lwIP demo for AT91SAM7X using Rowley tools.
2731 + Added uIP demo for AT91SAM7X using IAR tools.
2732 + Added function xTaskGetCurrentTaskHandle().
2733 + Renamed events.h to mevents.h to prevent it conflicting with the events.h
2734 generated automatically by the HCS12 processor expert utility. events.h
2735 is only used by the PC demo application.
2736 + Both PIC18 ports now initialise the TBLPTRU to 0 as this is the value
2737 expected by the compiler, and the compilers do not write to this
2739 + The HCS12 banked model demo now creates the 'suicide' tasks immediately
2740 prior to starting the scheduler. These tasks should be the last tasks to
2741 get started in order for the test to function correctly.
2743 Changes between V3.1.1 and V3.2.0 - Released 29 June, 2005
2745 V3.2.0 introduces two new MSP430 ports and corrects a minor kernel
2746 issues. Thanks to Ares.qi for his input.
2748 + Added two MSP430 ports that use the Rowley CrossWorks development tools.
2749 One port just mirrors the existing GCC port. The other port was provided
2750 by Milos Prokic. Thanks!
2751 + V3.2.0 corrects the behavior when vTaskPrioritySet() or vTaskResume()
2752 are called while the scheduler is locked (by a call to
2753 vTaskSuspendAll()). When this is done the subject task now starts to
2754 execute immediately when the scheduler is unlocked if it has the highest
2755 priority that is ready to run. Previously there was a possibility that
2756 the task would not run until the next RTOS tick or call to portYIELD().
2757 + Another similar small correction ensures that in the case where more than
2758 one task is blocked on a semaphore or queue, the task with the highest
2759 priority is guaranteed to be unblocked first.
2760 + Added a couple of more test tasks to the PC demo which cover the points
2763 Changes between V3.1.0 and V3.1.1 - Released 21st June, 2005
2765 This release updates the HCS12 port. The common kernel code
2768 + Updated the HCS12 port to support banking and introduced a demo
2769 application for the MC9S12DP256. The new demo application is
2770 located in the Demo/HCS12_CodeWarrior_banked directory.
2771 + The name of the directory containing the MC9S12F32 demo application
2772 has been changed to Demo/HCS12_CodeWarrior_small (as in 'small'
2774 + MC9S12F32 demo updated slightly to use the PLL. The CPU speed for the
2775 demo application is now 24MHz. Previously it was 8MHz.
2776 + The demo application file Demo/Common/Minimal/death.c has a slight
2777 alteration to prevent it using floating point variables.
2780 Changes between V3.0.0 and V3.1.0 - Released 11th June, 2005
2782 + Added new ports for ST Microsystems STR71x, and Freescale HCS12
2783 microcontrollers. Currently the HCS12 port is limited to the small
2784 memory model. Large memory models will be supported in the next
2786 + PIC18 wizC port updated. Thanks to Marcel van Lieshout for his
2787 continuing contribution.
2788 + The accuracy of the AVR port timer setup has been improved. Thanks to
2789 Thomas Krutmann for this contribution.
2790 + Added a new conditional compilation macro configIDLE_SHOULD_YIELD.
2791 See the WEB documentation for details.
2792 + Updated the CrossWorks uIP demo to build with V1.4 of CrossWorks.
2793 + Slight modification to the SAM7 release build configuration to correct
2794 an include path definition.
2795 + Updated the MPLAB PIC18 documentation to provide extra details on linker
2798 Changes between V3.0.0 and V2.6.1 - Released 23rd April, 2005
2800 V3.0.0 includes many enhancements, so this history list is broken into
2801 subsections as follows:
2805 Directory name changes
2806 Kernel and miscellaneous changes changes
2810 + Each port now defines BaseType_t as the data type that is most
2811 efficient for that architecture. The type BaseType_t is used
2812 extensively in API calls necessitating the following changes to the
2813 FreeRTOS API function prototypes.
2815 See the "New for V3.0.0" section of the FreeRTOS online
2816 documentation for full details of API changes.
2820 + The AT91FR40008 ARM7 port contributed by John Feller is now included
2821 in the download (thanks John!).
2822 + The PIC18 port for the wizC/fedC compiler contributed by Marcel van
2823 Lieshout is now included in the download (thanks Marcel!).
2824 + The IAR port for the AVR microcontroller has been upgraded to V3.0.0
2825 and is now a supported port.
2827 - Directory name changes
2829 For consistency, and to allow integration of the new ports, the
2830 following directory names have been changed.
2832 + The source/portable/GCC/ARM7 directory has been renamed
2833 source/portable/GCC/ARM7_LPC2000 so it is compatible with the naming
2834 of other GCC ARM7 ports.
2835 + The Demo/PIC directory has been renamed Demo/PIC18_MPLAB to
2836 accommodate the wizC/fedC PIC port.
2837 + The demo applications for the two AVR ports no longer share the same
2838 directory. The WinAVR demo is in the Demo/AVR_ATMega323_WinAVR
2839 directory and the IAR port in the Demo/AVR_ATMega323_IAR directory.
2842 - Kernel and miscellaneous changes changes
2844 See the "New for V3.0.0" section of the FreeRTOS online
2845 documentation for more information.
2847 + Previously 'portmacro.h' contained some user editable definitions
2848 relating to the user application, and some fixed definitions relating
2849 specifically to the port being used. The application specific
2850 definitions have been removed from 'portmacro.h' and placed inside a
2851 new header file called 'FreeRTOSConfig.h'. 'portmacro.h' should now
2852 never be modified by the user. A 'FreeRTOSConfig.h' is now included
2853 in each of FreeRTOS/Demo subdirectories - as it's settings relate to
2854 the demo application rather than being specific to the port.
2855 + Introduced configUSE_IDLE_HOOK in idle task.
2856 + The idle task will yield when another idle priority task is ready to
2857 run. Previously the idle task would run to the end of its time slice
2859 + The idle task is now created when the scheduler is started. This
2860 requires less stack than the previous scheme where it was created upon
2861 creation of the first application task.
2862 + The function usPortCheckFreeStackSpace() has been renamed
2863 usTaskCheckFreeStackSpace() and moved from the portable layer to
2865 + Corrected spelling of portMINMAL_STACK_SIZE to portMINIMAL_STACK_SIZE.
2866 + The portheap.c file included with the AVR port has been deleted. The
2867 AVR demo now uses the standard heap1 sample memory allocator.
2868 + The GCC AVR port is now build using the standard make utility. The
2869 batch files used previously have been deleted. This means a recent
2870 version of WinAVR is required in order to create a binary suitable for
2871 source level debugging.
2872 + vTaskStartScheduler() no longer takes the configUSE_PREEMPTION
2873 constant as a parameter. Instead the constant is used directly within
2874 tasks.c and no parameter is required.
2875 + The header file 'FreeRTOS.h' has been created and is used to include
2876 'projdefs.h', 'FreeRTOSConfig.h' and 'portable.h' in the necessary
2877 order. FreeRTOS.h can now be included in place of these other
2879 + The header file 'errors.h' has been deleted. The definitions it
2880 contained are now located within 'projdefs.h'.
2881 + pvPortMalloc() now takes a size_t parameter as per the ANSI malloc().
2882 Previously an unsigned short was used.
2883 + When resuming the scheduler a yield is performed if either a tick has
2884 been missed, or a task is moved from the pending ready list into a
2885 ready list. Previously a yield was not performed on this second
2887 + In heap1.c an overflow check has been added to ensure the next free
2888 byte variable does not wrap around.
2889 + Introduced the portTASK_FUNCTION() and portTASK_FUNCTION_PROTO()
2891 + The MPLAB PIC port now saved the TABLAT register in interrupt service
2894 Changes between V2.6.0 and V2.6.1 - Released Feb 22, 2005
2896 This version adds support for the H8 processor.
2900 + tskMAX_TASK_NAME_LEN removed from the task.h header and added to each
2901 individual portmacro.h file as portMAX_TASK_NAME_LEN. This allows RAM
2902 limited ports to allocate fewer characters to the task name.
2903 + AVR port - Replaced the inb() and outb() functions with direct memory
2904 access. This allows the port to be built with the 20050414 build of
2906 + GCC LPC2106 port - removed the 'static' from the definition of
2907 vNonPreemptiveTick() to allow the demo to link when using the cooperative
2909 + GCC LPC2106 port - Corrected the optimisation options in the batch files
2910 ROM_THUMB.bat, RAM_THUMB.bat, ROM_ARM.bat and RAM_ARM.bat. The lower case
2911 -o is replaced by an uppercase -O.
2912 + Tasks.c - The strcpy call has been removed when copying across the task
2914 + Updated the trace visualisation to always be 4 byte aligned so it can be
2915 used on ARM architectures.
2916 + There are now two tracecon executables (that convert the trace file binary
2917 into an ASCII file). One for big endian targets and one for little endian
2919 + Added ucTasksDeleted variable to prevent vTaskSuspendAll() being called
2920 too often in the idle task.
2921 + SAM7 USB driver - Replaced the duplicated RX_DATA_BK0 in the interrupt
2922 mask with the RX_DATA_BK1.
2925 Changes between V2.5.5 and V2.6.0 - Released January 16, 2005
2927 + Added the API function vTaskDelayUntil(). The demo app file
2928 Demo/Common/Minimal/flash.c has been updated to demonstrate its use.
2929 + Added INCLUDE_vTaskDelay conditional compilation.
2930 + Changed the name of the Demo/ARM7_AtmelSAM7S64_IAR directory to
2931 Demo/ARM7_AT91SAM7S64_IAR for consistency.
2932 + Modified the AT91SAM7S USB driver to allow descriptors that have
2933 a length that is an exact multiple of the FIFO to be transmitted.
2935 Changes between V2.5.4 and V2.5.5 - Released January 3, 2005
2937 This version adds support for the Atmel SAM7 ARM7 microcontrollers
2938 along with the IAR development tools.
2942 + Renamed the Demo/ARM7 directory to Demo/ARM7_LPC2106_GCC.
2943 + Renamed the Demo/ARM7_Keil directory to Demo/ARM7_LPC2129_Keil.
2944 + Modified the Philips ARM7 serial interrupt service routines to only
2945 process one interrupt per call. This seems to enable the ISR to
2946 operate more quickly.
2947 + Removed the 'far' keyword from the Open Watcom portable layer source
2948 files. This allows their use with V1.3 of Open Watcom.
2949 + Minor modifications to the SDCC build files to allow their use under
2950 Linux. Thanks to Frieder Ferlemann for this contribution.
2951 + Small change to sTaskCreate() to allow a context switch even when
2952 pxCreatedTask is NULL. Thanks to Kamil for this contribution.
2953 + inline keyword removed from vTaskSwitchContext() and VTaskIncrementTick()
2956 Changes between V2.5.3 and V2.5.4 - Released Dec 1, 2004
2958 This is an important maintenance release.
2960 The function cTaskResumeAll() has been modified so it can be used safely
2961 prior to the kernel being initialised. This was an issue as
2962 cTaskResumeAll() is called from pvPortMalloc(). Thanks to Daniel Braun
2963 for highlighting this issue.
2965 Changes between V2.5.2 and V2.5.3 - Released Nov 2, 2004
2967 The critical section handling functions have been changed for the GCC ARM7
2968 port. Some optimisation levels use the stack differently to others. This
2969 means the interrupt flags cannot always be stored on the stack and are
2970 instead now stored in a variable, which is then saved as part of the
2971 tasks context. This allows the GCC ARM7 port to be used at all
2972 optimisation levels - including -Os.
2974 Other minor changes:
2976 + MSP430 definition of usCriticalNesting now uses the volatile qualifier.
2977 This is probably not required but added just in case.
2979 Changes between V2.5.1 and V2.5.2 - Released Oct 26, 2004
2981 + Added the Keil ARM7 port.
2982 + Slight modification to comtest.c to make the delay periods more random.
2983 This creates a better test condition.
2985 Changes between V2.5.0 and V2.5.1 - Released Oct 9, 2004
2987 + Added the MSP430 port.
2988 + Extra comments added to the GCC ARM7 port.c and portISR.c files.
2989 + The memory pool allocated within heap_1.c has been placed within a
2990 structure to ensure correct memory alignment on 32bit systems.
2991 + Within the GCC ARM7 serial drivers an extra check is made to ensure
2992 the post to the queue was successful if then attempting immediately
2993 retrieve the posted character.
2994 + Changed the name of the constant portTICKS_PER_MS to portTICK_PERIOD_MS
2995 as the old name was misleading.
2998 Changes between V2.4.2 and V2.5.0 - Released Aug 12, 2004
3000 The RTOS source code download now includes three separate memory allocation
3001 schemes - so you can choose the most appropriate for your application.
3002 These are found in the Source/Portable/MemMang directory. The demo
3003 application projects have also been updated to demonstrate the new schemes.
3004 See the "Memory Management" page of the API documentation for more details.
3006 + Added heap_1.c, heap_2.c and heap_3.c in the Source/Portable/MemMang
3008 + Replaced the portheap.c files for each demo application with one of the
3009 new memory allocation files.
3010 + Updated the portmacro.h file for each demo application to include the
3011 constants required for the new memory allocators: portTOTAL_HEAP_SIZE and
3013 + Added a new test to the ARM7 demo application that tests the operation
3014 of the heap_2 memory allocator.
3017 Changes between V2.4.1 and V2.4.2 - Released July 14, 2004
3019 + The ARM7 port now supports THUMB mode.
3020 + Modification to the ARM7 demo application serial port driver.
3022 Changes between V2.4.0 and V2.4.1 - Released July 2, 2004
3024 + Rationalised the ARM7 port version of portEXIT_CRITICAL() -
3025 improvements provided by Bill Knight.
3026 + Made demo serial driver more complete and robust.
3029 Changes between V2.4.0 and V2.3.1 - Released June 30, 2004
3031 + Added the first ARM7 port - thanks to Bill Knight for the assistance
3033 + Added extra files to the Demo/Common/Minimal directory. These are
3034 equivalent to their Demo/Common/Full counterparts but with the
3035 calls to the functions defined in print.c removed.
3036 + Added TABLAT to the list of registers saved as part of a PIC18 context.
3038 Changes between V2.3.0 and V2.3.1 - Released June 25, 2004
3040 + Changed the way the vector table is defined to be more portable.
3041 + Corrected the definitions of SPH and SPL in portmacro.s90.
3042 The previous definitions prevented V2.3.0 operating if the iom323.h
3043 header file was included in portmacro.s90.
3045 Changes between V2.2.0 and V2.3.0 - Released June 19, 2004
3047 + Added an AVR port that uses the IAR compiler.
3048 + Explicit use of 'signed' qualifier on plain char types.
3049 + Modified the Open Watcom project files to use 'signed' as the
3051 + Changed odd calculation of initial pxTopOfStack value when
3052 portSTACK_GROWTH < 0.
3053 + Added inline qualifier to context switch functions within task.c.
3054 Ports that do not support the (non ANSI) inline keyword have the
3055 inline #define'd away in their respective portmacro.h files.
3057 Changes between V2.1.1 and V2.2.0 - Released May 18, 2004
3059 + Added Cygnal 8051 port.
3060 + PCLATU and PCLATH are now saved as part of the PIC18 context. This
3061 allows function pointers to be used within tasks. Thanks to Javier
3062 Espeche for the enhancement.
3063 + Minor changes to demo application files to reduce stack usage.
3064 + Minor changes to prevent compiler warnings when compiling the new port.
3066 Changes between V2.1.0 and V2.1.1 - Released March 12, 2004
3068 + Bug fix - pxCurrentTCB is now initialised before the call to
3069 prvInitialiseTaskLists(). Previously pxCurrentTCB could be accessed
3070 while null during the initialisation sequence. Thanks to Giuseppe
3071 Franco for the correction.
3073 Changes between V2.0.0 and V2.1.0 - Released Feb 29, 2004
3075 V2.1.0 has significant reworks that greatly reduce the amount of time
3076 the kernel has interrupts disabled. The first section of modifications
3077 listed here must be taken into account by users. The second section
3078 are related to the kernel implementation and as such are transparent.
3082 + The typedef TickType_t has been introduced. All delay times should
3083 now use a variable of type TickType_t in place of the unsigned long's
3084 used previously. API function prototypes have been updated
3086 + The configuration macro USE_16_BIT_TICKS has been introduced. If set
3087 to 1 TickType_t is defined as an unsigned short. If set to 0
3088 TickType_t is defined as an unsigned long. See the configuration
3089 section of the API documentation for more details.
3090 + The configuration macro INCLUDE_vTaskSuspendAll is now obsolete.
3091 + vTaskResumeAll() has been renamed cTaskResumeAll() as it now returns a
3092 value (see the API documentation).
3093 + ulTaskGetTickCount() has been renamed xTaskGetTickCount() as the type
3094 it returns now depends on the USE_16_BIT_TICKS definition.
3095 + cQueueReceive() must now >never< be used from within an ISR. Use the new
3096 cQueueReceiveFromISR() function instead.
3100 + A mechanism has been introduced that allows a queue to be accessed by
3101 a task and ISR simultaneously.
3102 + A "pending ready" queue has been introduced that enables interrupts to
3103 be processed when the scheduler is suspended.
3104 + The list implementation has been improved to provide faster item
3106 + The scheduler now makes use of the scheduler suspend mechanism in places
3107 where previously interrupts were disabled.
3109 Changes between V1.2.6 and V2.0.0 - Released Jan 31, 2004
3111 + Introduced new API functions:
3118 + Added conditional compilation options that allow the components of the
3119 kernel that are unused by an application to be excluded from the build.
3120 See the Configuration section on the WEB site for more information (on
3121 the API pages). The macros have been added to each portmacro.h file (
3122 sometimes called prtmacro.h).
3123 + Rearranged tasks.c.
3124 + Added demo application file dynamic.c.
3125 + Updated the PC demo application to make use of dynamic.c.
3126 + Updated the documentation contained in the kernel header files.
3127 + Creating a task now causes a context switch if the task being created
3128 has a higher priority than the calling task - assuming the kernel is
3130 + vTaskDelete() now only causes a context switch if the calling task is
3131 the task being deleted.
3133 Changes between V1.2.5 and V1.2.6 - Released December 31, 2003
3135 Barring the change to the interrupt vector (PIC port) these are minor
3138 + The interrupt vector used for the PIC master ISR has been changed from
3139 0x18 to 0x08 - where it should have always been. The incorrect address
3140 still works but probably executes a number of NOP's before getting to the
3142 + Changed the baud rate used by the AVR demo application to 38400. This
3143 has an error percentage of less than one percent with an 8MHz clock.
3144 + Raised the priority of the Rx task in demo\full\comtest.c. This only
3145 affects the Flashlite and PC ports. This was done to prevent the Rx
3146 buffer becoming full.
3147 + Reverted the Flashlite COM port driver back so it does not use the DMA.
3148 The DMA appears to miss characters under stress. The Borland Flashlite
3149 port was also calculating a register value incorrectly resulting in the
3150 wrong DMA source address being used. The same code worked fine when
3151 compiling with Open Watcom. Other minor enhancements were made to the
3153 + Modified the PIC serial Rx ISR to check for and clear overrun errors.
3154 Overrun errors seem to prevent any further characters being received.
3155 + The PIC demo projects now have some optimisation switched on.
3158 Changes between V1.2.4 and V1.2.5
3160 Small fix made to the PIC specific port.c file described below.
3162 + Introduced portGLOBAL_INTERRUPT_FLAG definition to test the global
3163 interrupt flag setting. Using the two bits defined within
3164 portINITAL_INTERRUPT_STATE was causing the w register to get clobbered
3165 before the test was performed.
3167 Changes between V1.2.3 and V1.2.4
3169 V1.2.4 contains a release version of the PIC18 port.
3170 An optional exception has been included with the GPL. See the licensing
3171 section of www.FreeRTOS.org for details.
3173 + The function xPortInitMinimal() has been renamed to
3174 xSerialPortInitMinimal() and the function xPortInit() has been renamed
3175 to xSerialPortInit().
3176 + The function sSerialPutChar() has been renamed cSerialPutChar() and
3177 the function return type changed to portCHAR.
3178 + The integer and flop tasks now include calls to tskYIELD(), allowing
3179 them to be used with the cooperative scheduler.
3180 + All the demo applications now use the integer and comtest tasks when the
3181 cooperative scheduler is being used. Previously they were only used with
3182 the preemptive scheduler.
3183 + Minor changes made to operation of minimal versions of comtest.c and
3185 + The ATMega port definition of portCPU_CLOSK_HZ definition changed to
3186 8MHz base 10, previously it base 16.
3190 Changes between V1.2.2a and V1.2.3
3192 The only change of any significance is to the license, which has changed
3193 from the Open Software License to the GNU GPL.
3195 The zip file also contains a pre-release version of the PIC18 port. This
3196 has not yet completed testing and as such does not constitute part of the
3197 V1.2.3 release. It is still however covered by the GNU GPL.
3199 There are minor source code changes to accommodate the PIC C compiler.
3200 These mainly involve more explicit casting.
3202 + sTaskCreate() has been modified slightly to make use of the
3203 portSTACK_GROWTH macro. This is required for the PIC port where the
3204 stack grows in the opposite direction to the other existing ports.
3205 + prvCheckTasksWaitingTermination() has been modified slightly to bring
3206 the decrementing of usCurrentNumberOfTasks within the critical section,
3207 where it should have been since the creation of an eight bit port.
3209 Changes between V1.2.2 and V1.2.2a
3211 The makefile and buildcoff.bat files included with the AVR demo application
3212 have been modified for use with the September 2003 build of WinAVR. No
3213 source files have changed.
3215 Changes between V1.2.1 and V1.2.2
3217 There are only minor changes here to allow the PC and Flashlite 186 ports
3218 to use the Borland V4.52 compiler, as supplied with the Flashlite 186
3221 + Introduced a BCC directory under source\portable. This contains all the
3222 files specific to the Borland compiler port.
3223 + Corrected the macro naming of portMS_PER_TICK to portTICKS_PER_MS.
3224 + Modified comtest.c to increase the rate at which the string is
3225 transmitted and received on the serial port. The Flashlite 186 demo
3226 app baud rate has also been increased.
3227 + The values of the constants used in both integer.c files have been
3228 increased to force the Borland compiler to use 32 bit values. The
3229 Borland optimiser placed the previous values in 16 bit registers, and in
3230 So doing invalidated the test.
3232 Changes between V1.2.0 and V1.2.1
3234 This version includes some minor changes to the list implementation aimed
3235 at improving the context switch time - with is now approximately 10% faster.
3236 Changes include the removal of some null pointer assignment checks. These
3237 were redundant where the scheduler uses the list functions, but means any
3238 user application choosing to use the same list functions must now check
3239 that no NULL pointers are passed as a parameter.
3241 The Flashlite 186 serial port driver has also been modified to use a DMA
3242 channel for transmissions. The serial driver is fully functional but still
3243 under development. Flashlite users may prefer to use V1.2.0 for now.
3247 + Changed the baud rate for the ATMega323 serial test from 19200 to 57600.
3248 + Use vSerialPutString() instead of single character puts in
3249 Demo\Full\Comtest.c. This allows the use of the flashlite DMA serial
3250 driver. Also the check variable only stops incrementing after two
3251 consecutive failures.
3252 + semtest.c creates four tasks, two of which operate at the idle priority.
3253 The tasks that operate at the idle priority now use a lower expected
3254 count than those running at a higher priority. This prevents the low
3255 priority tasks from signalling an error because they have not been
3256 scheduled enough time for each of them to count the shared variable to
3257 the higher original value.
3258 + The flashlite 186 serial driver now uses a DMA channel for transmissions.
3259 + Removed the volatile modifier from the list function parameters. This was
3260 only ever included to prevent compiler warnings. Now warnings are
3261 removed by casting parameters where the calls are made.
3262 + prvListGetOwnerOfNextEntry() and prvListGetOwnerOfHeadEntry() have been
3263 removed from list.c and added as macros in list.h.
3264 + usNumberOfItems has been added to the list structure. This removes the
3265 need for a pointer comparison when checking if a list is empty, and so
3267 + Removed the NULL check in vListRemove(). This makes the call faster but
3268 necessitates any application code utilising the list implementation to
3269 ensure NULL pointers are not passed.
3270 + Renamed portTICKS_PER_MS definition to portMS_PER_TICK (milli seconds
3271 per tick). This is what it always should have been.
3273 Changes between V1.01 and V1.2.0
3275 The majority of these changes were made to accommodate the 8bit AVR port.
3276 The scheduler workings have not changed, but some of the data types used
3277 have been made more friendly to an eight bit environment.
3281 + Changed the version numbering format.
3283 + Split the directory demo\common into demo\common\minimal and
3284 demo\common\full. The files in the full directory are for systems with
3285 a display (currently PC and Flashlite 186 demo's). The files in the
3286 minimal directory are for systems with limited RAM and no display
3287 (currently MegaAVR).
3288 + Minor changes to demo application function prototypes to make more use
3290 + Within the scheduler itself the following functions have slightly
3291 modified declarations to make use of 8bit data types where possible:
3295 usQueueMessageWaiting(),
3296 sQueueSendFromISR(),
3299 sSemaphoreGiveFromISR(),
3301 sTaskMoveFromEventList().
3303 Where the return type has changed the function name has also changed in
3304 accordance with the naming convention. For example
3305 usQueueMessageWaiting() has become ucQueueMessageWaiting().
3306 + The definition tskMAX_PRIORITIES has been moved from task.h to
3307 portmacro.h and renamed portMAX_PRIORITIES. This allows different
3308 ports to allocate a different maximum number of priorities.
3309 + By default the trace facility is off, previously USE_TRACE_FACILITY
3311 + comtest.c now uses a pseudo random delay between sends. This allows for
3312 better testing as the interrupts do not arrive at regular intervals.
3313 + Minor change to the Flashlite serial port driver. The driver is written
3314 to demonstrate the scheduler and is not written to be efficient.
3318 Changes between V1.00 and V1.01
3320 These changes improve the ports. The scheduler itself has not changed.
3322 Improved context switch mechanism used when performing a context
3323 switch from an ISR (both the tick ISR and the serial comms ISR's within
3324 the demo application). The new mechanism is faster and uses less stack.
3326 The assembler file portasm.asm has been replaced by a header file
3327 portasm.h. This includes a few assembler macro definitions.
3329 All saving and restoring of registers onto/off of the stack is now handled
3330 by the compiler. This means the initial stack setup for a task has to
3331 mimic the stack used by the compiler, which is different for debug and
3334 Slightly changed the operation of the demo application, details below.
3338 + portSWITCH_CONTEXT() replaced by vPortFirstContext().
3339 + pxPortInitialiseStack() modified to replicate the stack used by the
3341 + portasm.asm file removed.
3342 + portasm.h introduced. This contains macro definitions for
3343 portSWITCH_CONTEXT() and portFIRST_CONTEXT().
3344 + Context switch from ISR now uses the compiler generated interrupt
3345 mechanism. This is done simply by calling portSWITCH_CONTEXT and leaving
3346 the save/restore to compiler generated code.
3347 + Calls to taskYIELD() during ISR's have been replaced by calling the
3348 simpler and faster portSWITCH_CONTEXT().
3349 + The Flashlite 186 port now uses 186 instruction set (used to use 80x86
3351 + The blocking queue tasks within the demo application did not operate
3352 quite as described. This has been corrected.
3353 + The priority of the comtest Rx task within the demo application has been
3354 lowered. Received characters are now processed (read from the queue) at
3355 the idle priority, allowing low priority tasks to run evenly at times of
3356 a high communications overhead.
3357 + Prevent the call to kbhit() in main.c for debug builds as the debugger
3358 seems to have problems stepping over the call. This if for the PC port
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