1 Documentation and download available at https://www.FreeRTOS.org/
3 + Update all the APIs to use configSTACK_DEPTH_TYPE for stack type. If left
4 undefined, configSTACK_DEPTH_TYPE defaults to StackType_t.
6 Changes between FreeRTOS V11.0.0 and FreeRTOS V11.0.1 released December 21, 2023
8 + Updated the SBOM file.
10 Changes between FreeRTOS V10.6.2 and FreeRTOS V11.0.0 released December 18, 2023
12 + SMP merged into the mainline: While FreeRTOS introduced Asymmetric
13 Multiprocessing (AMP) support in 2017, FreeRTOS Version 11.0.0 is the
14 first to merge Symmetric Multiprocessing (SMP) support into the mainline
15 release. SMP enables one instance of the FreeRTOS Kernel to schedule tasks
16 across multiple identical processor cores. We thank Mike Bruno and Jerry
17 McCarthy of XMOS and, Darian Liang, Sudeep Mohanty and Zim Kalinowski of
18 Espressif Systems for their contributions.
19 + Switch MISRA compliance checking from PC Lint to Coverity, and update from
20 MISRA C:2004 to MISRA C:2012.
21 + Add a template FreeRTOSConfig.h, inclusive of an abbreviated explanation of
22 each configuration item. Application writers can use this template as a
23 starting point to create the FreeRTOSConfig.h file for their application.
24 + Add a template FreeRTOS port which can be used as a starting point for
25 developing a new FreeRTOS port.
26 + Add bounds checking and obfuscation to internal heap block pointers in
27 heap_4.c and heap_5.c to help catch pointer corruptions. The application can
28 enable these checks by setting configENABLE_HEAP_PROTECTOR to 1 in their
29 FreeRTOSConfig.h. We thank @oliverlavery for their contribution.
30 + Update vTaskList and vTaskGetRunTimeStats APIs to replace the use of sprintf
32 + Add trace macros to ports that enable tracing the interaction of ISRs with
33 scheduler events. We thank @conara for their contribution.
34 + Add trace macros that enable tracing of entering and exiting all APIs. We
35 thank @Techcore123 for their contribution.
36 + Add uxTaskBasePriorityGet and uxTaskBasePriorityGetFromISR APIs to get the
37 base priority of a task. The base priority of a task is the priority that
38 was last assigned to the task - which due to priority inheritance, may not
39 be the current priority of the task.
40 + Add pdTICKS_TO_MS macro to convert time in FreeRTOS ticks to time in
41 milliseconds. We thank @Dazza0 for their contribution.
42 + Add default implementations of vApplicationGetIdleTaskMemory and
43 vApplicationGetTimerTaskMemory. The application can enable these default
44 implementations by setting configKERNEL_PROVIDED_STATIC_MEMORY to 1 in their
45 FreeRTOSConfig.h. We thank @mdnr-g for their contribution.
46 + Update vTaskGetInfo to include start and end of the stack whenever both
47 values are available. We thank @vinceburns for their contribution.
48 + Prevent tasks waiting for a notification from being resumed by calls to
49 vTaskResume or vTaskResumeFromISR. We thank @Moral-Hao for their
51 + Add asserts to validate that the application has correctly installed
52 FreeRTOS handlers for PendSV and SVCall interrupts on Cortex-M devices.
53 We thank @jefftenney for their contribution.
54 + Rename ARM_CA53_64_BIT and ARM_CA53_64_BIT_SRE ports to Arm_AARCH64 and
55 Arm_AARCH64_SRE respectively as these ports are applicable to all AArch64
56 architecture. We thank @urutva for their contribution.
57 + Add CMake support to allow the application writer to select the RISC-V
58 chip extension. We thank @JoeBenczarski for their contribution.
59 + Add CMake support to allow the application writer to build an application
60 with static allocation only. We thank @conara for their contribution.
61 + Make taskYIELD available to unprivileged tasks for ARMv8-M ports.
62 + Update Cortex-M23 ports to not use PSPLIM_NS. We thank @urutva for their
64 + Update the SysTick setup code for ARMv8-M ports to first configure the clock
65 source and then enable SysTick. This is needed to address a bug in QEMU
66 versions older than 7.0.0, which causes an emulation error if SysTick is
67 enabled without first selecting a valid clock source. We thank @jefftenney
68 for their contribution.
69 + Add the port-optimized task selection algorithm optionally available for
70 ARMv7-M ports to the ARMv8-M ports. We thank @jefftenney for their
72 + Improve the speed of pvPortMalloc in heap_4.c and heap_5.c by removing
73 unnecessary steps while splitting a large memory block into two. We thank
74 @Moral-Hao for their contribution.
75 + Shorten the critical section in pvPortMalloc in heap_2.c, heap_4.c and
76 heap_5.c by moving the size calculation out of the critical section. We thank
77 @Moral-Hao for their contribution.
78 + Update xTaskNotifyWait and ulTaskNotifyTake to remove the non-deterministic
79 operation of traversing a linked link from a critical section. We thank
80 @karver8 for their contribution.
81 + Fix stack end and stack size computation in POSIX port to meet the stack
82 alignment requirements on MacOS. We thank @tegimeki for their contribution.
83 + Update the vTaskPrioritySet implementation to use the new priority when the
84 task has inherited priority from a mutex it is holding, and the new priority
85 is bigger than the inherited priority. We thank @Moral-Hao for their
87 + Add stack alignment adjustment if stack grows upwards. We thank @ivq for
89 + Fix pxTopOfStack calculation in configINIT_TLS_BLOCK when picolib C is
90 selected as the C library implementation to ensure that
91 pxPortInitialiseStack does not overwrite the data in the TLS block portion
92 of the stack. We thank @bebebib-rs for their contribution.
93 + Fix vPortEndScheduler() for the MSVC port so that the function
94 prvProcessSimulatedInterrupts is not stuck in an infinite loop when the
95 scheduler is stopped. We thank @Ju1He1 for their contribution.
96 + Add the Pull Request (PR) Process explaining the stages a PR goes through.
98 Changes between FreeRTOS V10.6.1 and FreeRTOS V10.6.2 released November 29, 2023
100 + Add the following improvements to the new MPU wrapper (mpu_wrappers_v2.c)
101 introduced in version 10.6.0:
102 - Introduce Access Control List (ACL) feature to allow the application
103 writer to control an unprivileged task’s access to kernel objects.
104 - Update the system call entry mechanism to only require one Supervisor
105 Call (SVC) instruction.
106 - Wrap parameters for system calls with more than four parameters in a
107 struct to avoid special handling during system call entry.
108 - Fix 2 possible integer overflows.
109 - Convert some asserts to run time parameter checks.
111 Changes between FreeRTOS V10.6.0 and FreeRTOS V10.6.1 released August 17, 2023
113 + Add runtime parameter checks to functions in mpu_wrappers_v2.c file.
114 The same checks are already performed in API implementations using
116 We thank the following people for their inputs in these changes:
117 - Lan Luo, Zixia Liu of School of Computer Science and Technology,
118 Anhui University of Technology, China.
119 - Xinwen Fu of Department of Computer Science, University of
120 Massachusetts Lowell, USA.
121 - Xinhui Shao, Yumeng Wei, Huaiyu Yan, Zhen Ling of School of
122 Computer Science and Engineering, Southeast University, China.
124 Changes between FreeRTOS V10.5.1 and FreeRTOS 10.6.0 released July 13, 2023
126 + Add a new MPU wrapper that places additional restrictions on unprivileged
127 tasks. The following is the list of changes introduced with the new MPU
130 1. Opaque and indirectly verifiable integers for kernel object handles:
131 All the kernel object handles (for example, queue handles) are now
132 opaque integers. Previously object handles were raw pointers.
133 2. Save the task context in Task Control Block (TCB): When a task is
134 swapped out by the scheduler, the task's context is now saved in its
135 TCB. Previously the task's context was saved on its stack.
136 3. Execute system calls on a separate privileged only stack: FreeRTOS
137 system calls, which execute with elevated privilege, now use a
138 separate privileged only stack. Previously system calls used the
139 calling task's stack. The application writer can control the size of
140 the system call stack using new configSYSTEM_CALL_STACK_SIZE config
142 4. Memory bounds checks: FreeRTOS system calls which accept a pointer
143 and de-reference it, now verify that the calling task has required
144 permissions to access the memory location referenced by the pointer.
145 5. System calls restrictions: The following system calls are no longer
146 available to unprivileged tasks:
149 - xQueueCreateMutexStatic
150 - xQueueCreateCountingSemaphore
151 - xQueueCreateCountingSemaphoreStatic
152 - xQueueGenericCreate
153 - xQueueGenericCreateStatic
155 - xQueueRemoveFromSet
164 - xTaskCallApplicationTaskHook
166 - vTaskGetRunTimeStats
169 - xEventGroupCreateStatic
171 - xStreamBufferGenericCreate
172 - xStreamBufferGenericCreateStatic
173 - vStreamBufferDelete
175 Also, an unprivileged task can no longer use vTaskSuspend to suspend
176 any task other than itself.
178 We thank the following people for their inputs in these enhancements:
179 - David Reiss of Meta Platforms, Inc.
180 - Lan Luo, Xinhui Shao, Yumeng Wei, Zixia Liu, Huaiyu Yan and Zhen Ling
181 of School of Computer Science and Engineering, Southeast University,
183 - Xinwen Fu of Department of Computer Science, University of
184 Massachusetts Lowell, USA.
185 - Yueqi Chen, Zicheng Wang, Minghao Lin, Jiahe Wang of University of
186 Colorado Boulder, USA.
187 + Add Cortex-M35P port. Contributed by @urutva.
188 + Add embedded extension (RV32E) support to the IAR RISC-V port.
189 + Add ulTaskGetRunTimeCounter and ulTaskGetRunTimePercent APIs. Contributed by
191 + Add APIs to get the application supplied buffers from statically
192 created kernel objects. The following new APIs are added:
193 - xTaskGetStaticBuffers
194 - xQueueGetStaticBuffers
195 - xQueueGenericGetStaticBuffers
196 - xSemaphoreGetStaticBuffer
197 - xEventGroupGetStaticBuffer
198 - xStreamBufferGetStaticBuffers
199 - xMessageBufferGetStaticBuffers
200 These APIs enable the application writer to obtain static buffers from
201 the kernel object and free/reuse them at the time of deletion. Earlier
202 the application writer had to maintain the association of static buffers
203 and the kernel object in the application. Contributed by @Dazza0.
204 + Add Thread Local Storage (TLS) support using picolibc function. Contributed
206 + Add configTICK_TYPE_WIDTH_IN_BITS to configure TickType_t data type. As a result,
207 the number of bits in an event group also increases with big data type. Contributed
209 + Update eTaskGetState and uxTaskGetSystemState to return eReady for pending ready
210 tasks. Contributed by @Dazza0.
211 + Update heap_4 and heap_5 to add padding only if the resulting block is not
213 + Fix the scheduler logic in a couple of places to not preempt a task when an
214 equal priority task becomes ready.
215 + Add macros used in FreeRTOS-Plus libraries. Contributed by @Holden.
216 + Fix clang compiler warnings. Contributed by @phelter.
217 + Add assertions to ARMv8-M ports to detect when FreeRTOS APIs are called from
218 interrupts with priority higher than the configMAX_SYSCALL_INTERRUPT_PRIORITY.
219 Contributed by @urutva.
220 + Add xPortIsInsideInterrupt API to ARM_CM0 ports.
221 + Fix build warning in MSP430X port when large data model is used.
222 + Add the ability to use Cortex-R5 port on the parts without FPU.
223 + Fix build warning in heap implementations on PIC24/dsPIC.
224 + Update interrupt priority asserts for Cortex-M ports so that these do not fire
225 on QEMU which does not implement PRIO bits.
226 + Update ARMv7-M ports to ensure that kernel interrupts run at the lowest priority.
227 configKERNEL_INTERRUPT_PRIORITY is now obsolete for ARMv7-M ports and brings
228 these ports inline with the newer ARMv8-M ports. Contributed by @chrisnc.
229 + Fix build issue in POSIX GCC port on Windows Subsystem for Linux (WSL). Contributed
231 + Add portMEMORY_BARRIER to Microblaze port. Contributed by @bbain.
232 + Add portPOINTER_SIZE_TYPE definition for ATmega port. Contributed by @jputcu.
233 + Multiple improvements in the CMake support. Contributed by @phelte and @cookpate.
235 Changes between FreeRTOS V10.5.0 and FreeRTOS V10.5.1 released November 16 2022
236 + Updated the kernel version in manifest and SBOM
238 Changes between FreeRTOS V10.4.6 and FreeRTOS V10.5.0 released September 16 2022
240 + ARMv7-M and ARMv8-M MPU ports: It was possible for a third party that
241 already independently gained the ability to execute injected code to
242 read from or write to arbitrary addresses by passing a negative argument
243 as the xIndex parameter to pvTaskGetThreadLocalStoragePointer() or
244 vTaskSetThreadLocalStoragePointer respectively. A check has been added to
245 ensure that passing a negative argument as the xIndex parameter does not
246 cause arbitrary read or write.
247 We thank Certibit Consulting, LLC for reporting this issue.
248 + ARMv7-M and ARMv8-M MPU ports: It was possible for an unprivileged task
249 to invoke any function with privilege by passing it as a parameter to
250 MPU_xTaskCreate, MPU_xTaskCreateStatic, MPU_xTimerCreate,
251 MPU_xTimerCreateStatic, or MPU_xTimerPendFunctionCall. MPU_xTaskCreate
252 and MPU_xTaskCreateStatic have been updated to only allow creation of
253 unprivileged tasks. MPU_xTimerCreate, MPU_xTimerCreateStatic and
254 MPU_xTimerPendFunctionCall APIs have been removed.
255 We thank Huazhong University of Science and Technology for reporting
257 + ARMv7-M and ARMv8-M MPU ports: It was possible for a third party that
258 already independently gained the ability to execute injected code to
259 achieve further privilege escalation by branching directly inside a
260 FreeRTOS MPU API wrapper function with a manually crafted stack frame.
261 The local stack variable `xRunningPrivileged` has been removed so that
262 a manually crafted stack frame cannot be used for privilege escalation
263 by branching directly inside a FreeRTOS MPU API wrapper.
264 We thank Certibit Consulting, LLC, Huazhong University of Science and
265 Technology and the SecLab team at Northeastern University for reporting
267 + ARMv7-M MPU ports: It was possible to configure overlapping memory
268 protection unit (MPU) regions such that an unprivileged task could access
269 privileged data. The kernel now uses highest numbered MPU regions for
270 kernel protections to prevent such MPU configurations.
271 We thank the SecLab team at Northeastern University for reporting this
273 + Add support for ARM Cortex-M55.
274 + Add support for ARM Cortex-M85. Contributed by @gbrtth.
275 + Add vectored mode interrupt support to the RISC-V port.
276 + Add support for RV32E extension (Embedded Profile) in RISC-V GCC port.
277 Contributed by @Limoto.
279 - Add a check to heap_2 to track if a memory block is allocated to
280 the application or not. The MSB of the size field is used for this
281 purpose. The same check already exists in heap_4 and heap_5. This
282 check prevents double free errors.
283 - Add a new flag configHEAP_CLEAR_MEMORY_ON_FREE to heap_2, heap_4
284 and heap_5. If the flag is set in FreeRTOSConfig.h then memory freed using
285 vPortFree() is automatically cleared to zero.
286 - Add a new API pvPortCalloc to heap_2, heap_4 and heap_5 which has the same
287 signature as the standard library calloc function.
288 - Update the pointer types to portPOINTER_SIZE_TYPE. Contributed by
290 + Add the ability to override send and receive completed callbacks for each
291 instance of a stream buffer or message buffer. Earlier there could be
292 one send and one receive callback for all instances of stream and message
293 buffers. Having separate callbacks per instance allows different message
294 and stream buffers to be used differently - for example, some for inter core
295 communication and others for same core communication.
296 The feature can be controlled by setting the configuration option
297 configUSE_SB_COMPLETED_CALLBACK in FreeRTOSConfig.h. When the option is set to 1,
298 APIs xStreamBufferCreateWithCallback() or xStreamBufferCreateStaticWithCallback()
299 (and likewise APIs for message buffer) can be used to create a stream buffer
300 or message buffer instance with application provided callback overrides. When
301 the option is set to 0, then the default callbacks as defined by
302 sbSEND_COMPLETED() and sbRECEIVE_COMPLETED() macros are invoked. To maintain
303 backwards compatibility, configUSE_SB_COMPLETED_CALLBACK defaults to 0. The
304 functionality is currently not supported for MPU enabled ports.
305 + Generalize the FreeRTOS's Thread Local Storage (TLS) support so that it
306 is not tied to newlib and can be used with other c-runtime libraries also.
307 The default behavior for newlib support is kept same for backward
309 + Add support to build and link FreeRTOS using CMake build system. Contributed
311 + Add support to generate Software Bill of Materials (SBOM) for every release.
312 + Add support for 16 MPU regions to the GCC Cortex-M33 ports.
313 + Add ARM Cortex-M7 r0p0/r0p1 Errata 837070 workaround to ARM CM4 MPU ports.
314 The application writer needs to define configENABLE_ERRATA_837070_WORKAROUND
315 when using CM4 MPU ports on a Cortex-M7 r0p0/r0p1 core.
316 + Add configSYSTICK_CLOCK_HZ to Cortex-M0 ports. This is needed to support
317 the case when the SysTick timer is not clocked from the same source as the CPU.
318 + Add hardware stack protection support to MicroBlazeV9 port. This ensures that
319 the CPU immediately raises Stack Protection Violation exception as soon as any
320 task violates its stack limits. Contributed by @uecasm.
321 + Introduce the configUSE_MINI_LIST_ITEM configuration option. When this
322 option is set to 1, ListItem_t and MiniLitItem_t remain separate types.
323 However, when configUSE_MINI_LIST_ITEM == 0, MiniLitItem_t and ListItem_t
324 are both typedefs of the same struct xLIST_ITEM. This addresses some issues
325 observed when strict-aliasing and link time optimization are enabled.
326 To maintain backwards compatibility, configUSE_MINI_LIST_ITEM defaults to 1.
327 + Simplify prvInitialiseNewTask to memset newly allocated TCB structures
328 to zero, and remove code that set individual structure members to zero.
329 + Add prototype for prvPortYieldFromISR to the POSIX port so that it builds
330 without any warning with -Wmissing-prototypes compiler option.
331 + Add top of stack and end of stack to the task info report obtained using
332 vTaskGetInfo(). Contributed by @shreyasbharath.
333 + Add a cap to the cRxLock and cTxLock members of the queue data structure.
334 These locks count the number items received and sent to the queue while
335 the queue was locked. These are later used to unblock tasks waiting on
336 the queue when the queue is unlocked. This PR caps the values of the
337 cRxLock and cTxLock to the number of tasks in the system because we cannot
338 unblock more tasks than there are in the system. Note that the same assert
339 could still be triggered is the application creates more than 127 tasks.
340 + Changed uxAutoReload parameter in timer functions to xAutoReload. The
341 type is now BaseType_t. This matches the type of pdTRUE and pdFALSE.
342 The new function xTimerGetAutoReload() provides the auto-reload state as
343 a BaseType_t. The legacy function uxTimerGetAutoReload is retained with the
344 original UBaseType_t return value.
345 + Fix support for user implementations of tickless idle that call
346 vTaskStepTick() with xExpectedIdleTime ticks to step. The new code
347 ensures xTickCount reaches xNextTaskUnblockTime inside xTaskIncrementTick()
348 instead of inside vTaskStepTick(). This fixes the typical case where a task
349 wakes up one tick late and a rare case assertion failure when xTickCount\
350 rolls over. Contributed by @jefftenney.
351 + Fix deadlock in event groups when pvPortMalloc and vPortFree functions
352 are protected with a mutex. Contributed by @clemenskresser.
353 + Fix a warning in tasks.c when compiled with -Wduplicated-branches
354 GCC option. Contributed by @pierrenoel-bouteville-act.
355 + Fix compilation error in tasks.c when configSUPPORT_DYNAMIC_ALLOCATION
356 is set to zero. Contributed by @rdpoor.
357 + Fix prvWriteMessageToBuffer() function in stream_buffer.c so that it correctly
358 copies length on big endian platforms too.
359 + Remove the need for INCLUDE_vTaskSuspend to be set to 1
360 when configUSE_TICKLESS_IDLE is enabled. Contributed by @pramithkv.
361 + Update the RL78 IAR port to the latest version of IAR which uses the
362 industry standard ELF format as opposed to earlier UBROF object format.
363 Contributed by @felipe-iar.
364 + Add tick type is atomic flag when tick count is 16-bit to PIC24 port. This
365 allows the PIC24 family of 16 bit processors to read the tick count without
366 a critical section when the tick count is also 16 bits.
367 + Fix offset-out-of-range errors for GCC CM3/CM4 mpu ports when
368 Link Time Optimization is enabled. Contributed by @niniemann.
369 + Remove #error when RISC-V port is compiled on a 64-bit RISC-V platform.
370 Contributed by @cmdrf.
371 + Fix ullPortInterruptNesting alignment in Cortex-A53 port so that it is
372 8-byte aligned. This fixes the unaligned access exception. Contributed
374 + Fix Interrupt Handler Register Function and Exception Process in NiosII
375 Port. Contributed by @ghost.
376 + Change FreeRTOS IRQ Handler for Cortex-A53 SRE port to store and restore
377 interrupt acknowledge register. This ensures that the SRE port behavior
378 matches the Memory Mapped IO port. Contributed by @sviaunxp.
379 + Update the uncrustify config file to match the version of the uncrustify
380 used in the CI Action. Also, pin the version of uncrustify in CI. Contributed
383 Changes between FreeRTOS V10.4.5 and FreeRTOS V10.4.6 released November 12 2021
385 + ARMv7-M and ARMv8-M MPU ports – prevent non-kernel code from calling the
386 internal functions xPortRaisePrivilege and vPortResetPrivilege by changing
388 + Introduce a new config configALLOW_UNPRIVILEGED_CRITICAL_SECTIONS which
389 enables developers to prevent critical sections from unprivileged tasks.
390 It defaults to 1 for backward compatibility. Application should set it to
391 0 to disable critical sections from unprivileged tasks.
393 Changes between FreeRTOS V10.4.4 and FreeRTOS V10.4.5 released September 10 2021
395 See https://www.FreeRTOS.org/FreeRTOS-V10.4.5.html
397 + Introduce configRUN_TIME_COUNTER_TYPE which enables developers to define
398 the type used to hold run time statistic counters. Defaults to uint32_t
399 for backward compatibility. #define configRUN_TIME_COUNTER_TYPE to a type
400 (for example, uint64_t) in FreeRTOSConfig.h to override the default.
401 + Introduce ulTaskGetIdleRunTimePercent() to complement the pre-existing
402 ulTaskGetIdleRunTimeCounter(). Whereas the pre-existing function returns
403 the raw run time counter value, the new function returns the percentage of
404 the entire run time consumed by the idle task. Note the amount of idle
405 time is only a good measure of the slack time in a system if there are no
406 other tasks executing at the idle priority, tickless idle is not used, and
407 configIDLE_SHOULD_YIELD is set to 0.
408 + ARMv8-M secure-side port: Tasks that call secure functions from the
409 non-secure side of an ARMv8-M MCU (ARM Cortex-M23 and Cortex-M33) have two
410 contexts - one on the non-secure side and one on the secure-side. Previous
411 versions of the FreeRTOS ARMv8-M secure-side ports allocated the structures
412 that reference secure-side contexts at run time. Now the structures are
413 allocated statically at compile time. The change necessitates the
414 introduction of the secureconfigMAX_SECURE_CONTEXTS configuration constant,
415 which sets the number of statically allocated secure contexts.
416 secureconfigMAX_SECURE_CONTEXTS defaults to 8 if left undefined.
417 Applications that only use FreeRTOS code on the non-secure side, such as
418 those running third-party code on the secure side, are not affected by
421 Changes between FreeRTOS V10.4.3 and FreeRTOS V10.4.4 released May 28 2021
422 + Minor performance improvements to xTaskIncrementTick() achieved by providing
423 macro versions of uxListRemove() and vListInsertEnd().
424 + Minor refactor of timers.c that obsoletes the need for the
425 tmrCOMMAND_START_DONT_TRACE macro and removes the need for timers.c to
426 post to its own event queue. A consequence of this change is that auto-
427 reload timers that miss their intended next execution time will execute
428 again immediately rather than executing again the next time the command
429 queue is processed. (thanks Jeff Tenney).
430 + Fix a race condition in the message buffer implementation. The
431 underlying cause was that length and data bytes are written and read as
432 two distinct operations, which both modify the size of the buffer. If a
433 context switch occurs after adding or removing the length bytes, but
434 before adding or removing the data bytes, then another task may observe
435 the message buffer in an invalid state.
436 + The xTaskCreate() and xTaskCreateStatic() functions accept a task priority
437 as an input parameter. The priority has always been silently capped to
438 (configMAX_PRIORITIES - 1) should it be set to a value above that priority.
439 Now values above that priority will also trigger a configASSERT() failure.
440 + Replace configASSERT( pcQueueName ) in vQueueAddToRegistry with a NULL
442 + Introduce the configSTACK_ALLOCATION_FROM_SEPARATE_HEAP configuration
443 constant that enables the stack allocated to tasks to come from a heap other
444 than the heap used by other memory allocations. This enables stacks to be
445 placed within special regions, such as fast tightly coupled memory.
446 + If there is an attempt to add the same queue or semaphore handle to the
447 queue registry more than once then prior versions would create two separate
448 entries. Now if this is done the first entry is overwritten rather than
450 + Update the ESP32 port and TF-M (Trusted Firmware M)code to the latest from
451 their respective repositories.
452 + Correct a build error in the POSIX port.
453 + Additional minor formatting updates, including replacing tabs with spaces
455 + Other minor updates include adding additional configASSERT() checks and
456 correcting and improving code comments.
457 + Go look at the smp branch to see the progress towards the Symetric
458 Multiprocessing Kernel. https://github.com/FreeRTOS/FreeRTOS-Kernel/tree/smp
460 Changes between FreeRTOS V10.4.2 and FreeRTOS V10.4.3 released December 14 2020
462 V10.4.3 is included in the 202012.00 LTS release. Learn more at https:/freertos.org/lts-libraries.html
464 See https://www.FreeRTOS.org/FreeRTOS-V10.4.x.html
466 + Changes to improve robustness and consistency for buffer allocation in
467 the heap, queue and stream buffer.
468 + The following functions can no longer be called from unprivileged code.
469 - xTaskCreateRestricted
470 - xTaskCreateRestrictedStatic
471 - vTaskAllocateMPURegions
474 Changes between FreeRTOS V10.4.1 and FreeRTOS V10.4.2 released November 10 2020
476 See https://www.FreeRTOS.org/FreeRTOS-V10.4.x.html
478 + Fix an issue in the ARMv8-M ports that caused BASEPRI to be masked
479 between the first task starting to execute and that task making
481 + Introduced xTaskDelayUntil(), which is functionally equivalent to
482 vTaskDelayUntil(), with the addition of returning a value to
483 indicating whether or not the function placed the calling task into
484 the Blocked state or not.
485 + Update WolfSSL to 4.5.0 and add the FIPS ready demo.
486 + Add support for ESP IDF 4.2 to ThirdParty Xtensa port.
487 + Re-introduce uxTopUsedPriority to support OpenOCD debugging.
488 + Convert most dependent libraries in FreeRTOS/FreeRTOS to submodules.
489 + Various general maintenance and improvements to MISRA compliance.
492 Changes between FreeRTOS V10.4.0 and FreeRTOS V10.4.1 released September 17 2020
494 See https://www.FreeRTOS.org/FreeRTOS-V10.4.x.html
496 + Fixed an incorrectly named parameter that prevented the
497 ulTaskNotifyTakeIndexed macro compiling, and the name space clash in the
498 test code that prevented this error causing test failures.
501 Changes between FreeRTOS V10.3.1 and FreeRTOS V10.4.0 released September 10 2020
503 See https://www.FreeRTOS.org/FreeRTOS-V10.4.x.html
507 + Task notifications: Prior to FreeRTOS V10.4.0 each created task had a
508 single direct to task notification. From FreeRTOS V10.4.0 each task has
509 an array of notifications. The direct to task notification API has been
510 extended with API functions postfixed with "Indexed" to enable the API to
511 operate on a task notification at any array index. See
512 https://www.freertos.org/RTOS-task-notifications.html for more information.
513 + Kernel ports that support memory protection units (MPUs): The ARMv7-M and
514 ARMv8-M MPU ports now support a privilege access only heap. The ARMv7-M
515 MPU ports now support devices that have 16 MPU regions, have the ability
516 to override default memory attributes for privileged code and data
517 regions, and have the ability to place the FreeRTOS kernel code outside of
518 the Flash memory. The ARMv8-M MPU ports now support tickless idle mode.
519 See https://www.freertos.org/FreeRTOS-MPU-memory-protection-unit.html
520 for more information.
522 Additional noteworthy updates:
524 + Code formatting is now automated to facilitate the increase in
525 collaborative development in Git. The auto-formated code is not identical
526 to the original formatting conventions. Most notably spaces are now used
528 + The prototypes for callback functions (those that start with "Application",
529 such as vApplicationStackOverflowHook()) are now in the FreeRTOS header
530 files, removing the need for application writers to add prototypes into
531 the C files in which they define the functions.
532 + New Renesas RXv3 port layer.
533 + Updates to the Synopsys ARC code, including support for EM and HS cores,
535 + Added new POSIX port layer that allows FreeRTOS to run on Linux hosts in
536 the same way the Windows port layer enables FreeRTOS to run on Windows
538 + Many other minor optimisations and enhancements. For full details
539 see https://github.com/FreeRTOS/FreeRTOS-Kernel/commits/main
542 Changes between FreeRTOS V10.3.0 and FreeRTOS V10.3.1 released February 18 2020
544 See https://www.FreeRTOS.org/FreeRTOS-V10.3.x.html
546 + ./FreeRTOS-Labs directory was removed from this file. The libraries it
547 contained are now available as a separate download.
549 Changes between FreeRTOS V10.2.1 and FreeRTOS V10.3.0 released February 7 2020
551 See https://www.FreeRTOS.org/FreeRTOS-V10.3.x.html
553 New and updated kernel ports:
555 + Added RISC-V port for the IAR compiler.
556 + Update the Windows simulator port to use a synchronous object to prevent
557 a user reported error whereby a task continues to run for a short time
558 after being moved to the Blocked state. Note we were not able to
559 replicate the reported issue and it likely depends on your CPU model.
560 + Correct alignment of stack top in RISC-V port when
561 configISR_STACK_SIZE_WORDS is defined to a non zero value, which causes
562 the interrupt stack to be statically allocated.
563 + The RISC-V machine timer compare register can now be for any HART, whereas
564 previously it was always assumed FreeRTOS was running on HART 0.
565 + Update the sequence used to update the 64-bit machine timer
566 compare register on 32-bit cores to match that suggested in RISC-V
568 + Added tickless low power modes into the ARM, IAR and GCC Cortex-M0 compiler
570 + Updated the behaviour of the ARMv7-M MPU (Memory Protection Unit) ports to
571 match that of the ARMv8-M ports whereby privilege escalations can only
572 originate from within the kernel's own memory segment. Added
573 configENFORCE_SYSTEM_CALLS_FROM_KERNEL_ONLY configuration constant.
574 + Update existing MPU ports to correctly disable the MPU before it is
576 + Added contributed port and demo application for a T-Head (formally C-SKY)
581 + Added the vPortGetHeapStats() API function which returns information on
582 the heap_4 and heap_5 state.
583 + Added xTaskCatchUpTicks(), which corrects the tick count value after the
584 application code has held interrupts disabled for an extended period.
585 + Added xTaskNotifyValueClear() API function.
586 + Added uxTimerGetReloadMode() API function.
588 Other miscellaneous changes:
589 + Change type of uxPendedTicks from UBaseType_t to TickType_t to ensure it
590 has the same type as variables with which it is compared to, and therefore
591 also renamed the variable xPendingTicks.
592 + Update Keil projects that use the MPU so memory regions come from linker
593 script (scatter file) variables instead of being hard coded.
594 + Added LPC51U68 Cortex-M0+ demos for GCC (MCUXpresso), Keil and IAR
596 + Added CORTEX_MPU_STM32L4_Discovery_Keil_STM32Cube demo.
597 + Added LPC54018 MPU demo.
598 + Rename xTaskGetIdleRunTimeCounter() to ulTaskGetIdleRunTimeCounter().
601 Changes between FreeRTOS V10.2.1 and FreeRTOS V10.2.0 released May 13 2019:
603 + Added ARM Cortex-M23 port layer to complement the pre-existing ARM
604 Cortex-M33 port layer.
605 + The RISC-V port now automatically switches between 32-bit and 64-bit
607 + Introduced the portMEMORY_BARRIER macro to prevent instruction re-ordering
608 when GCC link time optimisation is used.
609 + Introduced the portDONT_DISCARD macro to the ARMv8-M ports to try and
610 prevent the secure side builds from removing symbols required by the
611 non secure side build.
612 + Introduced the portARCH_NAME to provide additional data to select semi-
613 automated build environments.
614 + Cortex-M33 and Cortex-M23 ports now correctly disable the MPU before
615 updating the MPU registers.
617 + Added Nuvoton NuMaker-PFM-M2351 ARM Cortex-M23 demo.
618 + Added LPC55S69 ARM Cortex-M33 demo.
619 + Added an STM32 dual core AMP stress test demo.
622 Changes between FreeRTOS V10.1.1 and FreeRTOS V10.2.0 released February 25 2019:
624 + Added GCC RISC-V MCU port with three separate demo applications.
625 + Included pre-existing ARM Cortex-M33 (ARMv8-M) GCC/ARMclang and IAR ports
626 with Keil simulator demo.
627 + Update the method used to detect if a timer is active. Previously the
628 timer was deemed to be inactive if it was not referenced from a list.
629 However, when a timer is updated it is temporarily removed from, then
630 re-added to a list, so now the timer's active status is stored separately.
631 + Add vTimerSetReloadMode(), xTaskGetIdleRunTimeCounter(), and
632 xTaskGetApplicationTaskTagFromISR() API functions.
633 + Updated third party Xtensa port so it is MIT licensed.
634 + Added configINCLUDE_PLATFORM_H_INSTEAD_OF_IODEFINE_H to the Renesas
635 compiler RX600v2 port to enable switching between platform.h and
636 iodefine.h includes within that port's port.c file.
637 + Removed the 'FromISR' functions from the MPU ports as ISRs run privileged
639 + Added uxTaskGetStackHighWaterMark2() function to enable the return type to
640 be changed without breaking backward compatibility.
641 uxTaskGetStackHighWaterMark() returns a UBaseType_t as always,
642 uxTaskGetStackHighWaterMark2() returns configSTACK_DEPTH_TYPE to allow the
643 user to determine the return type.
644 + Fixed issues in memory protected ports related to different combinations
645 of static memory only and dynamic memory only builds. As a result the
646 definition of tskSTATIC_AND_DYNAMIC_ALLOCATION_POSSIBLE became more
647 complex and was moved to FreeRTOS.h with a table explaining its definition.
648 + Added a 'get task tag from ISR' function.
649 + Change the method used to determine if a timer is active or not from just
650 seeing if it is referenced from the active timer list to storing its
651 active state explicitly. The change prevents the timer reporting that it
652 is inactive while it is being moved from one list to another.
653 + The pcName parameter passed into the task create functions can be NULL,
654 previously a name had to be provided.
655 + When using tickless idle, prvResetNextTaskUnblockTime() is now only called
656 in xTaskRemoveFromEventList() if the scheduler is not suspended.
657 + Introduced portHAS_STACK_OVERFLOW_CHECKING, which should be set to 1 for
658 FreeRTOS ports that run on architectures that have stack limit registers.
661 Changes between FreeRTOS V10.1.0 and FreeRTOS V10.1.1 released 7 September 2018
663 + Reverted a few structure name changes that broke several kernel aware
665 + Updated to the latest trace recorder code.
666 + Fixed some formatting in the FreeRTOS+TCP TCP/IP stack code.
667 + Reverted moving some variables from file to function scope as doing so
668 broke debug scenarios that require the static qualifier to be removed.
670 Changes between FreeRTOS V10.0.1 and FreeRTOS V10.1.0 released 22 August 2018
672 FreeRTOS Kernel Changes:
674 + Update lint checked MISRA compliance to use the latest MISRA standard, was
675 previously using the original MISRA standard.
676 + Updated all object handles (TaskHandle_t, QueueHandle_t, etc.) to be
677 unique types instead of void pointers, improving type safety. (this was
678 attempted some years back but had to be backed out due to bugs in some
679 debuggers). Note this required the pvContainer member of a ListItem_t
680 struct to be renamed - set configENABLE_BACKWARD_COMPATIBILITY to 1 if
681 this causes an issue.
682 + Added configUSE_POSIX_ERRNO to enable per task POSIX style errno
683 functionality in a more user friendly way - previously the generic thread
684 local storage feature was used for this purpose.
685 + Added Xtensa port and demo application for the XCC compiler.
686 + Changed the implementation of vPortEndScheduler() for the Win32 port to
687 simply call exit( 0 ).
688 + Bug fix in vPortEnableInterrupt() for the GCC Microblaze port to protect
689 the read modify write access to an internal Microblaze register.
690 + Fix minor niggles when the MPU is used with regards to prototype
691 differences, static struct size differences, etc.
692 + The usStackHighWaterMark member of the TaskStatus_t structure now has type
693 configSTACK_DEPTH_TYPE in place of uint16_t - that change should have been
694 made when the configSTACK_DEPTH_TYPE type (which gets around the previous
695 16-bit limit on stack size specifications) was introduced.
696 + Added the xMessageBufferNextLengthBytes() API function and likewise stream
698 + Introduce configMESSAGE_BUFFER_LENGTH_TYPE to allow the number of bytes
699 used to hold the length of a message in the message buffer to be reduced.
700 configMESSAGE_BUFFER_LENGTH_TYPE default to size_t, but if, for example,
701 messages can never be more than 255 bytes it could be set to uint8_t,
702 saving 3 bytes each time a message is written into the message buffer
703 (assuming sizeof( size_t ) is 4).
704 + Updated the StaticTimer_t structure to ensure it matches the size of the
705 Timer_t structure when the size of TaskFunction_t does not equal the size
707 + Update various Xilinx demos to use 2018.1 version of the SDK tools.
708 + Various updates to demo tasks to maintain test coverage.
709 + FreeRTOS+UDP was removed in FreeRTOS V10.1.0 as it was replaced by
710 FreeRTOS+TCP, which was brought into the main download in FreeRTOS
711 V10.0.0. FreeRTOS+TCP can be configured as a UDP only stack, and
712 FreeRTOS+UDP does not contain the patches applied to FreeRTOS+TCP.
714 FreeRTOS+TCP Changes:
716 + Multiple security improvements and fixes in packet parsing routines, DNS
717 caching, and TCP sequence number and ID generation.
718 + Disable NBNS and LLMNR by default.
719 + Add TCP hang protection by default.
721 We thank Ori Karliner of Zimperium zLabs Team for reporting these issues.
724 Changes between FreeRTOS V10.0.0 and FreeRTOS V10.0.1, released December 20 2017
726 + Fix position of "#if defined( __cplusplus )" in stream_buffer.h.
727 + Correct declarations of MPU_xQueuePeek() and MPU_xQueueSemaphoreTake() in
729 + Correct formatting in vTaskList() helper function when it prints the state
730 of the currently executing task.
731 + Introduce #error if stream_buffer.c is built without
732 configUSE_TASK_NOTIFICATIONS set to 1.
733 + Update FreeRTOS+TCP to V2.0.0
734 - Improve the formatting of text that displays the available netword
735 interfaces when FreeRTOS+TCP is used on Windows with WinPCap.
736 - Introduce ipconfigSOCKET_HAS_USER_WAKE_CALLBACK option to enable a user
737 definable callback to execute when data arrives on a socket.
739 Changes between FreeRTOS V9.0.1 and FreeRTOS V10.0.0:
741 The FreeRTOS kernel is now MIT licensed: https://www.FreeRTOS.org/license
743 New Features and components:
745 + Stream Buffers - see https://www.FreeRTOS.org/RTOS-stream-buffer-example.html
746 + Message Buffers - see https://www.FreeRTOS.org//RTOS-message-buffer-example.html
747 + Move FreeRTOS+TCP into the main repository, along with the basic Win32
748 TCP demo FreeRTOS_Plus_TCP_Minimal_Windows_Simulator.
752 + Added demo for TI SimpleLink CC3220 MCU.
753 + Added MPU and non MPU projects for Microchip CEC and MEC 17xx and 51xx
755 + Added CORTEX_MPU_Static_Simulator_Keil_GCC demo to test static allocation
758 Fixes or enhancements:
760 + Cortex-M ports push additional register prior to calling
761 vTaskSwitchContext to ensure 8-byte alignment is maintained. Only
762 important if a user defined tick hook function performs an operation that
763 requires 8-byte alignment.
764 + Optimisations to the implementation of the standard tickless idle mode on
766 + Improvements to the Win32 port including using higher priority threads.
767 + Ensure interrupt stack alignment on PIC32 ports.
768 + Updated GCC TriCore port to build with later compiler versions.
769 + Update mpu_wrappers.c to support static allocation.
770 + The uxNumberOfItems member of List_t is now volatile - solving an issue
771 when the IAR compiler was used with maximum optimization.
772 + Introduced configRECORD_STACK_HIGH_ADDRESS. When set to 1 the stack start
773 address is saved into each task's TCB (assuming stack grows down).
774 + Introduced configINCLUDE_FREERTOS_TASK_C_ADDITIONS_H to allow user defined
775 functionality, and user defined initialisation, to be added to FreeRTOS's
776 tasks.c source file. When configINCLUDE_FREERTOS_TASK_C_ADDITIONS_H is
777 set to 1 a user provided header file called freertos_task_c_additions.h
778 will be included at the bottom of tasks.c. Functions defined in that
779 header file can call freertos_tasks_c_additions_init(), which in turn
780 calls a macro called FREERTOS_TASKS_C_ADDITIONS_INIT(), if it is defined.
781 FREERTOS_TASKS_C_ADDITIONS_INIT() can be defined in FreeRTOSConfig.h.
782 + Introduced configPRE_SUPPRESS_TICKS_AND_SLEEP_PROCESSING( x ) which can be
783 defined by a user in FreeRTOSConfig.h. The macro is called before
784 assessing whether to enter tickless idle mode or not. If the macro sets
785 x to zero then tickless idle mode will not be entered. This allows users
786 to abort tickless idle mode entry before the tickless idle function is
787 even called - previously it was only possible to abort from within the
788 tickless idle function itself.
789 + Added configPRINTF(), which can be defined by users to allow all libraries
790 to use the same print formatter.
791 + Introduced configMAX() and configMIN() macros which default to standard
792 max( x, y ) and min( x, y ) macro behaviour, but can be overridden if the
793 application writer defines the same macros in FreeRTOSConfig.h.
794 + Corrected the definition of StaticTask_t in the case where
795 INCLUDE_xTaskAbortDelay is set to 1.
796 + Introduced configTIMER_SERVICE_TASK_NAME and configIDLE_TASK_NAME, both of
797 which can be defined to strings in FreeRTOSConfig.h to change the default
798 names of the timer service and idle tasks respectively.
799 + Only fill the stack of a newly created task with a known value if stack
800 checking, or high water mark checking/viewing, is in use - removing the
801 dependency on memset() in other cases.
802 + Introduced xTaskCreateRestrictedStatic() so static allocation can be used
804 + Ensure suspended tasks cannot be unsuspended by a received task
806 + Fix race condition in vTaskSetTimeOutState().
807 + Updated trace recorder files to the latest version.
809 Changes since FreeRTOS V9.0.0:
811 + Priority dis-inheritance behaviour has been enhanced in the case where a
812 task that attempted to take a mutex that was held by a lower priority task
813 timed out before it was able to obtain the mutex (causing the task that
814 holds the mutex to have its priority raised, then lowered again, in
815 accordance with the priority inheritance protocol).
816 + Split the overloaded xQueueGenericReceive() function into three separate
818 + Allow the default human readable text names given to the Idle and Timer
819 tasks to be overridden by defining the configIDLE_TASK_NAME and
820 configTIMER_SERVICE_TASK_NAME definitions respectively in FreeRTOSConfig.h.
821 + Introduced configINITIAL_TICK_COUNT to allow the tick count to take a
822 value of than than 0 when the system boots. This can be useful for
823 testing purposes - although setting configUSE_16_BIT_TICKS to 1 can also
824 be used to test frequent tick overflows.
825 + Ensure the Cortex-M SysTick count is cleared to zero before starting the
827 + Add configASSERT() into ARM Cortex-M ports to check the number of priority
829 + Clear the 'control' register before starting ARM Cortex-M4F ports in case
830 the FPU is used before the scheduler is started. This just saves a few
831 bytes on the main stack as it prevents space being left for a later save
833 + Added xSemaphoreGetMutexHolderFromISR().
834 + Corrected use of portNVIC_PENDSVSET to portNVIC_PENDSVSET_BIT in MPU ports.
835 + Introduced configSTACK_DEPTH_TYPE to allow users to change the type used
836 to specify the stack size when using xTaskCreate(). For historic reasons,
837 when FreeRTOS was only used on small MCUs, the type was set to uint16_t,
838 but that can be too restrictive when FreeRTOS is used on larger
839 processors. configSTACK_DEPTH_TYPE defaults to uint16_t.
840 xTaskCreateStatic(), being a newer function, used a uint32_t.
841 + Increase the priority of the Windows threads used by the Win32 port. As
842 all the threads run on the same core, and the threads run with very high
843 priority, there is a risk that the host will become unresponsive, so also
844 prevent the Windows port executing on single core hosts.
846 Changes between FreeRTOS V9.0.0 and FreeRTOS V9.0.0rc2 released May 25 2016:
848 See https://www.FreeRTOS.org/FreeRTOS-V9.html
852 + The prototype of the new xTaskCreateStatic() API function was modified to
853 remove a parameter and improve compatibility with other new
854 "CreateStatic()" API functions. The stack size parameter in
855 xTaskCreateStatic() is now uint32_t, which changes the prototype of the
856 callback functions. See the following URL:
857 https://www.FreeRTOS.org/xTaskCreateStatic.html
858 + GCC ARM Cortex-A port: Introduced the configUSE_TASK_FPU_SUPPORT
859 constant. When configUSE_TASK_FPU_SUPPORT is set to 2 every task is
860 automatically given a floating point (FPU) context.
861 + GCC ARM Cortex-A port: It is now possible to automatically save and
862 restore all floating point (FPU) registers on entry to each potentially
863 nested interrupt by defining vApplicationFPUSafeIRQHandler() instead of
864 vApplicationIRQHandler().
865 + All ARM Cortex-M3/4F/7 ports: Clear the least significant bit of the task
866 entry address placed onto the stack of a task when the task is created for
867 strict compliance with the ARM Cortex-M3/4/7 architecture documentation
868 (no noticeable effect unless using the QMEU emulator).
869 + Added GCC and Keil ARM Cortex-M4F MPU ports - previously the MPU was only
870 supported on ARM Cortex-M3.
871 + ARM Cortex-M3/4F MPU ports: Update to fully support the FreeRTOS V9.0.0
872 API (other than static object creation) and added the
873 FreeRTOS/Demo/CORTEX_MPU_Simulator_Keil_GCC demo application to
874 demonstrate how to use the updated MPU port.
875 + All ARM Cortex-M3/4F/7 ports: Add additional barrier instructions to the
876 default low power tickless implementation.
877 + All ARM Cortex-M0 ports: Prevent an item being left on the stack of the
878 first task that executes.
879 + Win32 ports: Reduce the amount of stack used and change the way Windows
880 threads are deleted to increase the maximum execution time.
881 + Add an ARM Cortex-M4F port for the MikroC compiler. Ensure to read the
882 documentation page for this port before use.
883 + MPS430X IAR port: Update to be compatible with the latest EW430 tools
885 + IAR32 GCC port: Correct vPortExitCritical() when
886 configMAX_API_CALL_INTERRUPT_PRIORITY == portMAX_PRIORITY.
887 + For consistency vTaskGetTaskInfo() now has the alias vTaskGetInfo(),
888 xTaskGetTaskHandle() now has the alias xTaskGetHandle() and
889 pcQueueGetQueueName() now has an alias pcQueueGetName().
890 + Fix various errors in comments and compiler warnings.
892 Demo application updates:
894 + Update Atmel Studio projects to use Atmel Studio 7.
895 + Update Xilinx SDK projects to use the 2016.1 version of the SDK.
896 + Remove dependency on legacy IO libraries from the PIC32 demos.
897 + Move the Xilinx UltraScale Cortex-R5 demo into the main distribution.
898 + Update the MSP432 libraries to the latest version.
899 + Add Microchip CEC1302 (ARM Cortex-M4F) demos for GCC, Keil and MikroC
901 + Move the Atmel SAMA5D2 demo into the main distribution.
903 Changes between FreeRTOS V9.0.0rc1 and FreeRTOS V9.0.0rc2 (release candidate 2)
904 released March 30 2016:
906 NOTE - See https://www.FreeRTOS.org/FreeRTOS-V9.html for details
908 + The functions that create RTOS objects using static memory allocation have
909 been simplified and will not revert to using dynamic allocation if a
910 buffer is passed into a function as NULL.
911 + Introduced the configSUPPORT_DYNAMIC_ALLOCATION configuration constant to
912 allow a FreeRTOS application to be built without a heap even being being
913 defined. The Win32 example located in the
914 /FreeRTOS/demo/WIN32-MSVC-Static-Allocation-Only directory is provided as
915 a reference for projects that do not include a FreeRTOS heap.
916 + Minor run-time optimisations.
917 + Two new low power tickless implementations that target Silicon Labs EFM32
919 + Addition of the xTimerGetPeriod() and xTimerGetExpireTime() API functions.
921 Changes between FreeRTOS V8.2.3 and FreeRTOS V9.0.0rc1 (release candidate 1)
922 released February 19 2016:
926 + Major new feature - tasks, semaphores, queues, timers and event groups can
927 now be created using statically allocated memory, so without any calls to
929 + Major new features - Added the xTaskAbortDelay() API function which allows
930 one task to force another task to immediately leave the Blocked state,
931 even if the event the blocked task is waiting for has not occurred, or the
932 blocked task's timeout has not expired.
933 + Updates necessary to allow FreeRTOS to run on 64-bit architectures.
934 + Added vApplicationDaemonTaskStartupHook() which executes when the RTOS
935 daemon task (which used to be called the timer service task) starts
936 running. This is useful if the application includes initialisation code
937 that would benefit from executing after the scheduler has been started.
938 + Added the xTaskGetTaskHandle() API function, which obtains a task handle
939 from the task's name. xTaskGetTaskHandle() uses multiple string compare
940 operations, so it is recommended that it is called only once per task.
941 The handle returned by xTaskGetTaskHandle() can then be stored locally for
943 + Added the pcQueueGetQueueName() API function, which obtains the name of
944 a queue from the queue's handle.
945 + Tickless idling (for low power applications) can now also be used when
946 configUSE_PREEMPTION is 0.
947 + If one task deletes another task, then the stack and TCB of the deleted
948 task is now freed immediately. If a task deletes itself, then the stack
949 and TCB of the deleted task are freed by the Idle task as before.
950 + If a task notification is used to unblock a task from an ISR, but the
951 xHigherPriorityTaskWoken parameter is not used, then pend a context switch
952 that will then occur during the next tick interrupt.
953 + Heap_1.c and Heap_2.c now use the configAPPLICATION_ALLOCATED_HEAP
954 settings, which previously was only used by heap_4.c.
955 configAPPLICATION_ALLOCATED_HEAP allows the application writer to declare
956 the array that will be used as the FreeRTOS heap, and in-so-doing, place
957 the heap at a specific memory location.
958 + TaskStatus_t structures are used to obtain details of a task.
959 TaskStatus_t now includes the bae address of the task's stack.
960 + Added the vTaskGetTaskInfo() API function, which returns a TaskStatus_t
961 structure that contains information about a single task. Previously this
962 information could only be obtained for all the tasks at once, as an array
963 of TaskStatus_t structures.
964 + Added the uxSemaphoreGetCount() API function.
965 + Replicate previous Cortex-M4F and Cortex-M7 optimisations in some
966 Cortex-M3 port layers.
968 Demo Application Updates:
970 Further demo applications will be added prior to the final FreeRTOS V9
973 + Updated SAM4L Atmel Studio project to use Atmel Studio 7.
974 + Added ARM Cortex-A53 64-bit port.
975 + Added a port and demo for the ARM Cortex-A53 64-bit cores on the Xilinx
977 + Added Cortex-M7 SAME70 GCC demo.
978 + Added EFM32 Giant and Wonder Gecko demos.
981 Changes between V8.2.2 and V8.2.3 released October 16, 2015
985 + Fix bug identified in a modification made in V8.2.2 to the software timer
986 code that allows tickless low power applications to sleep indefinitely
987 when software timers are used.
988 + Simplify and improve efficiency of stack overflow checking.
989 + Add xTaskNotifyStateClear() API function.
990 + New IAR and GCC Cortex-R ports for microprocessors that do not use an ARM
991 generic interrupt controller (GIC).
992 + New PIC32MEC14xx port.
993 + Add support for PIC32MZ EF parts (with floating point) into the PIC32MZ
995 + Zynq7000 port layer now declares the functions that setup and clear the
996 tick interrupt as weak symbols so they can be overridden by the
997 application, and uses a global XScuGic object so the same object can be
998 used by the application code.
999 + Introduced configUSE_TASK_FPU_SUPPORT, although the PIC32MZ EF port is
1000 currently the only port that uses it.
1001 + Updates to RL78 and 78K0 IAR port layers to improve support for
1002 combinations of memory models.
1003 + Minor updates to heap_5.c to remove compiler warnings generated by some
1005 + License simplifications. See /FreeRTOS/License/license.txt in the
1006 official distribution.
1010 + Update directory names to use WolfSSL instead of CyaSSL, inline with
1011 WolfSSL's re-branding.
1012 + Update to latest WolfSSL code.
1013 + Update to latest FreeRTOS+Trace recorder code.
1014 + Add in the FreeRTOS+Trace recorder library required for streaming trace.
1016 Demo application changes:
1018 + Add demo applications for Renesas RZ/T (Cortex-R), PIC32MZ EF (PIC32 with
1019 floating point hardware), PIC32MEC14xx, RX71M, RX113 and RX231.
1020 + General tidy up of spelling and compiler warnings.
1023 Changes between V8.2.1 and V8.2.2 released August 12, 2015
1025 RTOS kernel updates:
1027 + Added Intel IA32/x86 32-bit port.
1028 + General maintenance.
1029 + PRIVILEGED_FUNCTION and PRIVILEGED_DATA macros, which are used in memory
1030 protected systems, have been added to the newer event group and software
1032 + Add the errno definitions used by FreeRTOS+ components into projdefs.h.
1033 + Remove the restriction that prevented tick-less idle implementations
1034 waiting indefinitely when software timers were used in the same
1036 + Introduce xTaskNotifyAndQueryFromISR() as the interrupt safe version of
1037 xTaskNotifyAndQuery().
1038 + Add additional NOPs to the MSP430X port layers to ensure strict compliance
1039 with the hardware documentation.
1040 + Microblaze port: Added option for port optimised task selection.
1041 + Microblaze port: Previously tasks inherited the exception enable state
1042 at the time the task was created. Now all tasks are created with
1043 exceptions enabled if the Microblaze design supports exceptions.
1044 + Windows port: Add additional safe guards to ensure the correct start up
1045 sequence and thread switching timing.
1046 + Windows port: Improve the implementation of the port optimised task
1047 selection assembly code.
1048 + Update heap_4 and heap_5 to allow use on 64-bit processors.
1049 + Simplify the code that creates a queue.
1050 + General improved tick-less idle behaviour.
1051 + Ensure none of the variables in the common kernel files are initialised to
1052 anything other than zero.
1053 + Correct calculation of xHeapStructSize in heap_4 and heap_5.
1055 Demo application updates:
1057 + Added demo project for the new IA32/x86 port that targets the Galileo
1059 + Added MSP430FR5969 demos (previously provided as a separate download).
1060 + Added FreeRTOS BSP repository for automatic creation of FreeRTOS
1061 applications in the Xilinx SDK.
1062 + Added Atmel Studio / GCC project for the SAMV71 (ARM Cortex-M7)
1063 + Update Xilinx SDK projects to use version 2015.2 of the SDK.
1064 + Remove Microblaze demos that were using obsolete tools.
1065 + Add MSP43FR5969 IAR and CCS demos.
1069 + Updated FreeRTOS+Trace recorder library, which requires an update to the
1070 FreeRTOS+Trace application.
1071 + Added Reliance Edge source code and demo application. Reliance edge is
1072 a fail safe transactional file system ideal for applications that require
1073 file storage, and especially when high reliability is essential.
1074 + Introduce configAPPLICATION_PROVIDES_cOutputBuffer to allow FreeRTOS+CLI
1075 users to place the output buffer at a fixed memory address.
1076 + Improve the NetworkInterface.c file provided for the Windows port of
1079 Changes between V8.2.0 and V8.2.1 released 24th March 2015.
1081 RTOS kernel updates:
1083 + Added user definable and flexible thread local storage facility.
1084 + Added vTimerSetTimerID() API function to complement the pvTimerGetTimerID()
1085 function to allow the timer's ID to be used as timer local storage.
1086 + Fixed a potential issue related to the use of queue sets from an ISR.
1087 + Some updates to the Xilinx Microblaze GCC port.
1088 + Added ARM Cortex-M4F port for Texas Instruments Code Composer Studio.
1089 + Added ARM Cortex-M7 r0p1 port layer for IAR, GCC and Keil which contains a
1090 minor errata work around. All other ARM Cortex-M7 core revisions should
1091 use the ARM Cortex-M4F port.
1092 + Exclude the whole of croutine.c if configUSE_CO_ROUTINES is set to 0.
1093 + Change some data types from uint32_t to size_t in preparation for 64-bit
1095 + Update the PIC32 port to remove deprecation warnings output by the latest
1097 + Fix bug when xQueueOverwrite() and xQueueOverwrite() from ISR are used to
1098 overwrite items in two queues that are part of the same set.
1100 Demo application updates:
1102 + Added demo application for TI's ARM Cortex-M4F based MSP432
1103 microcontroller using IAR, Keil and CCS compilers.
1104 + Added demo application for STM32F ARM Cortex-M7 based microcontroller
1106 + Added demo application for Atmel SAMV71 ARM Cortex-M7 based
1107 microcontroller using IAR and Keil.
1108 + Added Microblaze demo that uses the 2014.4 version of the Xilinx SDK and
1109 runs on the KC705 evaluation board (Kintex FPGA).
1111 Changes between V8.1.2 and V8.2.0 released 16th January 2015
1113 Changes between release candidate 1 and the official release are restricted
1114 to maintenance only.
1116 Significant RTOS kernel updates:
1118 + MAJOR NEW FEATURE! Task notifications. Please see the following URL for
1119 details: https://www.FreeRTOS.org/RTOS-task-notifications.html
1120 + NEW HEADER FILE REQUIRED! Obsolete definitions have been separated into
1121 a new header file called FreeRTOS/Source/include/deprecated_definitions.h.
1122 This header file must be present to build. Note some of the obsolete
1123 definitions are still used by very old demo application projects.
1125 Other RTOS kernel updates:
1127 + Made xSemaphoreGiveFromISR() a function rather than a macro that calls
1128 xQueueGenericSendFromISR(). This allows for major performance
1129 enhancements at the expense of some additional code size if both functions
1130 are used in the same application. NOTE: In most uses cases such use of
1131 a semaphore can now be replaced with a task notification which is smaller
1133 + The TCB is now always allocated such that the task's stack grows away from
1134 the TCB (improves debugging of stack overflows as the overflow will not
1135 overwrite the task's name).
1136 + GCC, IAR and Keil Cortex-M4F ports now use more inlining (performance
1137 enhancements at the cost of a little additional code space).
1138 + Queues are now allocated with a single call to pvPortMalloc() which
1139 allocates both the queue structure and the queue storage area.
1140 + Introduced a new critical section macro for reading the tick count that
1141 defines away to nothing in cases where the width of the tick allows the
1142 tick count to be read atomically (performance benefits - especially when
1143 optimisation is on).
1144 + Introduced configAPPLICATION_ALLOCATED_HEAP in heap_4.c to allow the
1145 application writer to provide their own heap array - and in so doing
1146 control the location of the heap.
1147 + Introduced configUSE_LIST_DATA_INTEGRITY_CHECK_BYTES which, when set, will
1148 include known values in both list and list item structures. The values
1149 are intended to assist debugging. If the values get overwritten then it
1150 is likely application code has written over RAM used by the kernel.
1151 + configASSERT()s in all Cortex-M ports used to test the lowest 5 bits of
1152 the interrupt control register to detect taskENTER_CRITICAL() being called
1153 from an interrupt. This has been changed to test all 8 bits.
1154 + Introduced uxTaskPriorityGetFromISR().
1155 + Microblze V8 port now tests XPAR_MICROBLAZE_0_USE_FPU for inequality to 0
1156 rather than equality to 1, and 2 and 3 are also valid values.
1157 + Cortex-A5 GIC-less port no longer passes the address of the interrupting
1158 peripheral into the interrupt handler.
1159 + Fix an issue in FreeRTOS-MPU where an attempt was made to free the stack
1160 belonging to a task when the task was deleted, even when the stack was
1161 allocated statically.
1162 + Utility (helper) functions that format task statistic information into
1163 human readable tables now pad task names with spaces to ensure columns
1164 line up correctly even where task name lengths vary greatly.
1165 + Update FreeRTOS+Trace recorder library to version 2.7.0.
1167 Demo application updates:
1169 + Added two new standard demo task sets: IntSemTest and TaskNotify.
1170 + Added port and demo application for Atmel SAMA5D4 Cortex-A5 MPU.
1171 + Added demo application for Altera Cyclone V Cortex-A9 MPU.
1172 + Updated Zynq demo to use version 2014.4 of Xilinx's SDK and added in
1173 demo tasks for new RTOS features.
1174 + Updated Atmel SAM4E and SAM4S demos to include a lot of additional test
1176 + Fixed a corner case issue in Atmel SAM4L low power tickless
1177 implementation, and added button interrupt handling.
1178 + Make the interrupt queue tests more tolerant to heave CPU loads.
1179 + Updated MSVC FreeRTOS simulator demo to include the latest standard test
1181 + Updated MingW/Eclipse FreeRTOS simulator demo to match the FreeRTOS MSVC
1183 + Updated all demos that use FreeRTOS+Trace to work with the latest trace
1187 Changes between V8.1.1 and V8.1.2 released September 2nd 2014
1189 Move the defaulting of configUSE_PORT_OPTIMISED_TASK_SELECTION into the
1190 individual port layers where necessary so it does not affect ports that do
1191 not support the definition.
1193 Changes between V8.1.0 and V8.1.1 released August 29th 2014
1195 By popular requests - a minor patch to V8.1.0 to re-instate the ability to
1196 give a mutex type semaphore (with priority inheritance) from an interrupt
1199 Changes between V8.0.1 and V8.1.0 released August 26th 2014
1201 FreeRTOS scheduler, kernel, demo and test updates:
1203 + Improved the priority inheritance algorithms to assist integration with
1204 off the shelf middleware that may hold multiple mutexes simultaneously.
1205 + Introduce heap_5.c, which is similar to heap_4.c but allows the heap to
1206 span multiple non-contiguous memory regions.
1207 + Updated all Cortex-A9 ports to help trap a couple of common usage errors -
1208 the first being when a task incorrectly attempts to exit its implementing
1209 function and the second being when a non interrupt safe API function is
1210 called from an interrupt.
1211 + Update all Cortex-A9 ports to remove obsolete mode switches prior to
1212 restoring a task context.
1213 + configUSE_PORT_OPTIMISED_TASK_SELECTION now defaults to 1 instead of 0.
1214 + Update all Cortex-M3/4F ports to trap a non interrupt safe API function
1215 being called from an interrupt handler.
1216 + Simplify the alignment checks in heap_4.c.
1217 + Update the MSVC Windows simulator demo to use heap_5.c in place of
1218 heap_4.c to ensure end users have an example to refer to.
1219 + Updated standard demo test code to test the new priority inheritance
1221 + Updated the standard demo tasks to make use of stdint and the FreeRTOS
1222 specific typedefs that were introduced in FreeRTOS V8.0.0.
1223 + Introduce the pdMS_TO_TICKS() macro as a more user friendly and intuitive
1224 alternative to pdTICKS_PER_MS - both of which can be used to convert a
1225 time specified in milliseconds to a time specified in RTOS ticks.
1226 + Fix a bug in the Tasking compiler's Cortex-M port that resulted in an
1227 incorrect value being written to the basepri register. This only effects
1228 users of the Tasking compiler.
1229 + Update the Zynq demo to use version 2014.2 of the SDK and add in an lwIP
1230 example that demonstrates lwIP being used with both its raw and sockets
1232 + Updated the CCS Cortex-R4 port to enable it to be built with the latest
1235 New ports and demo applications:
1237 + Two Renesas RX64M ports (RXv2 core) and demos introduced, one for the GCC
1238 compiler and one for the Renesas compiler. Both demos use e2 studio.
1239 + Generic IAR Cortex-A5 port (without any reliance on a GIC) introduced.
1240 The new port is demonstrated on an Atmel SAMA5D3 XPlained board.
1242 FreeRTOS+ component updates:
1244 + Update CyaSSL to the latest version.
1245 + Updated the FreeRTOS+ components supplied directly by Real Time Engineers
1246 Ltd. to make use of stdint and the FreeRTOS specific typedefs that were
1247 introduced in FreeRTOS V8.0.0.
1248 + Rework and simplify the FreeRTOS+FAT SL RAM disk driver.
1250 Miscellaneous updates and maintenance:
1252 + Update the IAR and DS-5/ARM RZ demos to target the official RZ RSK
1253 hardware in place of the previously targeted Renesas internal (not
1254 publicly available) hardware.
1255 + Various other maintenance tasks.
1258 Changes between V8.0.0 and V8.0.1 released 2nd May 2014
1260 + Minor fixes to the event group functionality that was released in V8.0.0.
1261 The 'clear bits from ISR' functionality is now implemented using a
1262 deferred interrupt callback instead of a function, and the 'wait bits' and
1263 'task sync' functions now correctly clear internal control bits before
1264 returning a value in every possible path through the respective functions.
1265 + Ensure the updating of internal control data is protected by a critical
1266 section after a task is deleted or suspended.
1267 + Minor fixes to FreeRTOS+FAT SL - namely seeking beyond the end of a file
1268 when the offset was not a multiple of the sector size.
1269 + Ensure Cortex-A9 system registers are only ever accessed as 32-bit values,
1270 even when only the lest significant byte of the register is implemented.
1274 + Updated the XMC4200 IAR project so it links with version 7.x of the IAR
1277 + Add pcTimerGetName() API function.
1278 + Call _reclaim_reent() when a task is deleted if configUSE_NEWLIB_REENTRANT
1281 Changes between V7.6.0 and V8.0.0 released 19th Feb 2014
1283 https://www.FreeRTOS.org/upgrading-to-FreeRTOS-V8.html
1285 FreeRTOS V8.x.x is a drop-in compatible replacement for FreeRTOS V7.x.x,
1286 although a change to the type used to reference character strings may result
1287 in application code generating a few (easily clearable) compiler warnings
1288 after the upgrade, and an updated typedef naming convention means use of the
1289 old typedef names is now discouraged.
1290 See https://www.FreeRTOS.org/upgrading-to-FreeRTOS-V8.html for full
1293 New features and functionality:
1295 + Event groups - see https://www.FreeRTOS.org/FreeRTOS-Event-Groups.html
1296 + Centralised deferred interrupt processing - see
1297 https://www.FreeRTOS.org/xTimerPendFunctionCallFromISR.html
1301 + Previously, when a task left the Blocked state, a context switch was
1302 performed if the priority of the unblocked task was greater than or equal
1303 to the priority of the Running task. Now a context switch is only
1304 performed if the priority of the unblocked task is greater than the
1305 priority of the Running task.
1306 + New low power tickless demonstration project that targets the ST STM32L
1307 microcontroller - see
1308 https://www.FreeRTOS.org/STM32L-discovery-low-power-tickless-RTOS-demo.html
1309 + Add xPortGetMinimumEverFreeHeapSize() to heap_4.c.
1310 + Small change to the tickless low power implementation on the SAM4L to
1311 ensure the alarm value (compare match value) cannot be set to zero when a
1312 tickless period is exited due to an interrupt originating from a source
1313 other than the RTOS tick.
1314 + Update the GCC/Eclipse Win32 simulator demo to make better use of Eclipse
1315 resource filters and match the functionality of the MSVC equivalent.
1316 + xTaskIsTaskSuspended() is no longer a public function. Use
1317 eTaskGetState() in its place.
1318 + Improved trace macros, including tracing of heap usage.
1319 + Remove one level of indirection when accepting interrupts on the PIC32MZ.
1320 + Add Cortex-A9 GCC port layer.
1321 + Add Xilinx Zynq demo application.
1324 Changes between V7.5.3 and V7.6.0 released 18th November 2013
1326 V7.6.0 changes some behaviour when the co-operative scheduler is used (when
1327 configUSE_PREEMPTION is set to 0). It is important to note that the
1328 behaviour of the pre-emptive scheduler is unchanged - the following
1329 description only applies when configUSE_PREEMPTION is set to 0:
1331 WHEN configUSE_PREEMPTION IS SET TO 0 (which is in a small minority of
1332 cases) a context switch will now only occur when a task places itself into
1333 the Blocked state, or explicitly calls taskYIELD(). This differs from
1334 previous versions, where a context switch would also occur when implicitly
1335 moving a higher priority task out of the Blocked state. For example,
1336 previously, WHEN PREEMPTION WAS TURNED OFF, if task A unblocks task B by
1337 writing to a queue, then the scheduler would switch to the higher priority
1338 task. Now, WHEN PREEMPTION IS TURNED OFF, if task A unblocks task B by
1339 writing to a queue, task B will not start running until task A enters the
1340 Blocked state or task A calls taskYIELD(). [If configUSE_PREEMPTION is not
1341 set to 0, so the normal pre-emptive scheduler is being used, then task B
1342 will start running immediately that it is moved out of the Blocked state].
1346 + Added a port layer and a demo project for the new PIC32MZ architecture.
1347 + Update the PIC32MX port layer to re-introduce some ehb instructions that
1348 were previously removed, add the ability to catch interrupt stack
1349 overflows (previously only task stack overflows were trapped), and also
1350 add the ability to catch an application task incorrectly attempting to
1351 return from its implementing function.
1352 + Make dramatic improvements to the performance of the Win32 simulator port
1354 + Ensure tasks that are blocked indefinitely report their state as Blocked
1355 instead of Suspended.
1356 + Slight improvement to the Cortex-M4F port layers where previously one
1357 register was inadvertently being saved twice.
1358 + Introduce the xSemaphoreCreateBinary() API function to ensure consistency
1359 in the semantics of how each semaphore type is created. It is no longer
1360 recommended to use vSemaphoreCreateBinary() (the version prefixed with a
1361 'v'), although it will remain in the code for backward compatibility.
1362 + Update the Cortex-M0 port layers to allow the scheduler to be started
1363 without using the SVC handler.
1364 + Added a build configuration to the PIC32MX MPLAB X demo project that
1365 targets the PIC32 USB II starter kit. Previously all the build
1366 configurations required the Explorer 16 hardware.
1367 + Some of the standard demo tasks have been updated to ensure they execute
1368 correctly with the updated co-operative scheduling behaviour.
1369 + Added comprehensive demo for the Atmel SAM4E, including use of
1370 FreeRTOS+UDP, FreeRTOS+FAT SL and FreeRTOS+CLI.
1374 + Minor maintenance on FreeRTOS+UDP.
1376 Changes between V7.5.2 and V7.5.3 released October 14 2013
1380 + Prior to V7.5.x yields requested from the tick hook would occur in the
1381 same tick interrupt - revert to that original behaviour.
1382 + New API function uxQueueSpacesAvailable().
1383 + Introduced the prvTaskExitError() function to Cortex-M0, Cortex-M3/4
1384 and Cortex-M4F ports. prvTaskExitError() is used to trap tasks that
1385 attempt to return from their implementing functions (tasks should call
1386 vTaskDelete( NULL ); if they want to exit).
1387 + The Cortex-M0 version of portSET_INTERRUPT_MASK_FROM_ISR and
1388 portCLEAR_INTERRUPT_MASK_FROM_ISR are now fully nestable.
1389 + Improved behaviour and robustness of the default Cortex-M tickless idle
1391 + Add workaround for silicon errata PMU_CM001 in Infineon XMC4000 devices to
1392 all Cortex-M4F ports.
1393 + Add Cortex-M0 port for Keil.
1394 + Updated Cortus port.
1395 + Ensure _impure_ptr is initialised before the scheduler is started.
1396 Previously it was not set until the first context switch.
1400 + Update FreeRTOS+UDP to V1.0.1 - including direct integration of the
1401 FreeRTOS+Nabto task, improvements to the DHCP behaviour, and a correction
1402 to the test that prevents the network event hook being called on the first
1403 network down event. The FreeRTOS+UDP change history is maintained
1405 + Correct the __NVIC_PRIO_BITS setting in the LPC18xx.h header files
1406 provided in the NXP CMSIS library, then update the interrupts used by the
1407 LPC18xx demos accordingly.
1408 + Replace double quotes (") with single quotes (') in FreeRTOS+CLI help
1409 strings to ensure the strings can be used with the JSON descriptions used
1410 in the FreeRTOS+Nabto demos.
1412 Demo and miscellaneous changes:
1414 + Added demo for the Atmel SAMD20 Cortex-M0+. The demo includes
1416 + Added a demo for the Infineon Cortex-M0 that can be built with the IAR
1418 + Updated the Infineon XMC4000 demos for IAR, Keil, GCC and Tasking tools,
1419 with additional build configurations to directly support the XMC4200 and
1420 XMC4400 devices, in addition to the previously supported XMC4500.
1421 + Updated the demo application.
1422 + Added additional trace macros traceMALLOC and traceFREE to track heap
1425 Changes between V7.5.0 and V7.5.2 released July 24 2013
1427 V7.5.2 makes the new Cortex-M vPortCheckInterruptPriority() function
1428 compatible with the STM32 standard peripheral driver library, and adds
1429 an extra critical section to the default low power tickless mode
1430 implementation. Only users of the STM32 peripheral library or the default
1431 tickless implementation need update from version 7.5.0.
1433 Changes between V7.4.2 and V7.5.0 released July 19 2013
1435 V7.5.0 is a major upgrade that includes multiple scheduling and efficiency
1436 improvements, and some new API functions.
1438 Compatibility information for FreeRTOS users:
1439 FreeRTOS V7.5.0 is backward compatible with FreeRTOS V7.4.0 with one
1440 exception; the vTaskList() and vTaskGetRunTimeStats() functions are now
1441 considered legacy, having been replaced by the single uxTaskGetSystemState()
1442 function. configUSE_STATS_FORMATTING_FUNCTIONS must be set to 1 in
1443 FreeRTOSConfig.h for vTaskList() and vTaskGetRunTimeStats() to be
1446 Compatibility information for FreeRTOS port writers:
1447 vTaskIncrementTick() is now called xTaskIncrementTick() (because it now
1452 + Multiple scheduling and efficiency improvements.
1453 + Core kernel files now pass PC-Lint V8 static checking without outputting
1454 any warnings (information on the test conditions will follow).
1458 + uxTaskGetSystemState() https://www.FreeRTOS.org/uxTaskGetSystemState.html
1459 + xQueueOverwrite() https://www.FreeRTOS.org/xQueueOverwrite.html
1460 + xQueueOverwriteFromISR()
1461 + xQueuePeekFromISR()
1463 The following ports and demos, which were previously available separately,
1464 are now incorporated into the main FreeRTOS zip file download:
1467 + ARM Cortex-A9 ARM compiler
1469 + Microsemi SmartFusion2
1471 New FreeRTOSConfig.h settings
1472 https://freertos.org/a00110.html
1474 + configUSE_TIME_SLICING
1475 + configUSE_NEWLIB_REENTRANT
1476 + configUSE_STATS_FORMATTING_FUNCTIONS
1477 + configINCLUDE_APPLICATION_DEFINED_PRIVILEGED_FUNCTIONS
1481 + (MPU port only) The configINCLUDE_APPLICATION_DEFINED_PRIVILEGED_FUNCTIONS
1482 options provides a mechanism that allows application writers to execute
1483 certain functions in privileged mode even when a task is running in user
1485 + Ports that support interrupt nesting now include a configASSERT() that
1486 will trigger if an interrupt safe FreeRTOS function is called from an
1487 interrupt that has a priority designated as above the maximum system/API
1488 call interrupt priority.
1489 + The included FreeRTOS+Trace recorder code has been updated to the latest
1490 version, and the demo applications that use the trace recorder code have
1491 been updated accordingly.
1492 + The FreeRTOS Windows Simulator (MSVC version only) has been updated to
1493 include a new basic 'blinky' build option in addition to the original
1494 comprehensive build option.
1495 + Improve RAM usage efficiency of heap_4.c and heap_2.c.
1496 + Prevent heap_4.c from attempting to free memory blocks that were not
1497 allocated by heap_4.c, or have already been freed.
1498 + As FreeRTOS now comes with FreeRTOS+FAT SL (donated by HCC) the Chan FATfs
1499 files have been removed from FreeRTOS/Demo/Common.
1500 + Fix build error when R4 port is build in co-operative mode.
1501 + Multiple port and demo application maintenance activities.
1503 Changes between V7.4.1 and V7.4.2 released May 1 2013
1505 NOTE: There are no changes in the FreeRTOS kernel between V7.4.1 and V7.4.2
1507 + Added FreeRTOS+FAT SL source code and demo project. The demo project
1508 runs in the FreeRTOS Windows simulator for easy and hardware independent
1509 experimentation and evaluation. See https://www.FreeRTOS.org/fat_sl
1511 Changes between V7.4.0 and V7.4.1 released April 18 2013
1513 + To ensure strict conformance with the spec and ensure compatibility with
1514 future chips data and instruction barrier instructions have been added to
1515 the yield macros of Cortex-M and Cortex-R port layers. For efficiency
1516 the Cortex-M port layer "yield" and "yield" from ISR are now implemented
1517 separately as the barrier instructions are not required in the ISR case.
1518 + Added FreeRTOS+UDP into main download.
1519 + Reorganised the FreeRTOS+ directory so it now matches the FreeRTOS
1520 directory with Source and Demo subdirectories.
1521 + Implemented the Berkeley sockets select() function in FreeRTOS+UDP.
1522 + Changed (unsigned) casting in calls to standard library functions with
1524 + Added the Atmel SAM4L and Renesas RX100 demos that demonstrates the
1525 tickless (tick suppression) low power FreeRTOS features.
1526 + Add a new RL78 IAR demo that targets numerous new RL78 chips and
1528 + Adjusted stack alignment on RX200 ports to ensure an assert was not
1529 falsely triggered when configASSERT() is defined.
1530 + Updated the Cortex_M4F_Infineon_XMC4500_IAR demo to build with the latest
1532 + Corrected header comments in the het.c and het.h files (RM48/TMS570 demo).
1535 Changes between V7.3.0 and V7.4.0 released February 20 2013
1537 + New feature: Queue sets. See:
1538 https://www.FreeRTOS.org/Pend-on-multiple-rtos-objects.html
1539 + Overhauled the default tickless idle mode implementation provided with the
1540 ARM Cortex-M3 port layers.
1541 + Enhanced tickless support in the core kernel code with the introduction of
1542 the configEXPECTED_IDLE_TIME_BEFORE_SLEEP macro and the
1543 eTaskConfirmSleepModeStatus() function.
1544 + Added the QueueSet.c common demo/test file. Several demo applications
1545 have been updated to use the new demo/test tasks.
1546 + Removed reliance on the PLIB libraries from the MPLAB PIC32 port layer and
1548 + Added the FreeRTOS+Trace recorder code to the MSVC Win32 demo.
1549 + Renamed eTaskStateGet() to eTaskGetState() for consistency, and added a
1550 pre-processor macro for backward compatibility with the previous name.
1551 + Updated functions implemented in the core queue.c source file to allow
1552 queue.h to be included from the .c file directly (this prevents compiler
1553 warnings that were generated by some compilers).
1554 + Updated the CCS Cortex-R4 port layer to replace the CLZ assembler function
1555 with the CLZ compiler intrinsic that is provided by the latest versions of
1556 the CCS ARM compiler.
1557 + Updated all heap_x.c implementations to replace the structure that was
1558 used to ensure the start of the heap was aligned with a more portable
1559 direct C code implementation.
1560 + Added support for PIC24 devices that include EDS.
1561 + Minor optimisations to the PIC32 port layer.
1562 + Minor changes to tasks.c that allow the state viewer plug-ins to display
1563 additional information.
1564 + Bug fix: Update prvProcessReceivedCommands() in timers.c to remove an
1565 issue that could occur if the priority of the timer daemon task was set
1566 below the priority of tasks that used timer services.
1567 + Update the FreeRTOS+Trace recorder code to the latest version.
1569 Changes between V7.2.0 and V7.3.0 released October 31 2012
1571 + Added ability to override the default scheduler task selection mechanism
1572 with implementations that make use of architecture specific instructions.
1573 + Added ability to suppress tick interrupts during idle time, and in so
1574 doing, provide the ability to make use of architecture specific low power
1576 + Added the portSUPPRESS_TICKS_AND_SLEEP() macro and vTaskStepTick() helper
1578 + Added the configSYSTICK_CLOCK_HZ configuration constant.
1579 + Reworked the Cortex-M3 and Cortex-M4F port layers for GCC, Keil and IAR to
1580 directly support basic power saving functionality.
1581 + Added hooks to allow basic power saving to be augmented in the application
1582 by making use of chip specific functionality.
1583 + Minor change to allow mutex type semaphores to be used from interrupts
1584 (which would not be a normal usage model for a mutex).
1585 + Change the behaviour of the interrupt safe interrupt mask save and restore
1586 macros in the Cortex-M ports. The save macro now returns the previous
1587 mask value. The restore macro now uses the previous mask value. These
1588 changes are not necessary for the kernel's own implementation, and are
1589 made purely because the macros were being used by application writers.
1590 + Added eTaskStateGet() API function.
1591 + Added port specific optimisations to the PIC32 port layer, and updated the
1592 PIC32 demo applications to make use of this new feature.
1593 + Added port specific optimisations to the Win32 simulator port.
1594 + Added new ports and demo applications for the TI Hercules RM48 and TMS570
1595 safety microcontrollers.
1596 + Added SAM3 demos targeting the ATSAM3S-EK2 and ATSAM3X-EK evaluation
1598 + Updated the PIC32 MPLAB X project to manually set the compiler include
1599 paths instead of using the IDE entry box following reports that the
1600 include paths were somehow being deleted.
1601 + Improved character handling in FreeRTOS+CLI.
1603 Changes between V7.1.1 and V7.2.0 released 14 August 2012
1605 FreeRTOS V7.2.0 is backward compatible with FreeRTOS V7.1.2.
1607 + Added a FreeRTOS+ sub-directory. The directory contains some FreeRTOS+
1608 source code, and example projects that use the FreeRTOS Win32 simulator.
1609 + Added a new example heap allocation implementation (heap_4.c) that
1610 includes memory block coalescence.
1611 + Added a demo that targets the Atmel SAM4S Cortex-M4 based microcontroller.
1612 The demo is preconfigured to build using the free Atmel Studio 6 IDE and
1614 + Added xSemaphoreTakeFromISR() implementation.
1615 + The last parameter in ISR safe FreeRTOS queue and semaphore functions
1616 (xHigherPriorityTaskWoken) is now optional and can be set to NULL if it
1618 + Update the IAR and MSP430X ports to clear all lower power mode bits before
1619 exiting the tick interrupt [bug fix].
1620 + Allow xQueueReset() to be used, even when the queues event lists are not
1622 + Added a vQueueDelete() handler for the FreeRTOS MPU port (this was
1623 previously missing).
1624 + Updated the vPortSVCHandler() functions in the FreeRTOS MPU port layer to
1625 ensure it compiles with the latest ARM GCC compilers from Linaro.
1626 + Updated the prvReadGP() function in the NIOS II port to ensure the compiler
1627 can choose any register for the functions parameter (required at high
1628 compiler optimisation levels).
1629 + Add #error macros into the Keil and IAR Cortex-M ports to ensure they
1630 cannot be built if the user has set configMAX_SYSCALL_INTERRUPT_PRIORITY
1632 + Added comments in the FreeRTOSConfig.h files associated with Cortex-M3 and
1633 Cortex-M4 demos stating that the configMAX_SYSCALL_INTERRUPT_PRIORITY
1634 parameter must not be set to 0.
1635 + Introduce new INCLUDE_xQueueGetMutexHolder configuration constant
1637 + Added two new list handling macros - for internal use only in upcoming new
1639 + Removed all mention of the legacy vTaskStartTrace and ulTaskEndTrace
1640 macros. FreeRTOS+Trace supersedes the legacy trace.
1641 + Added a configASSERT() into the vPortFree() function in heap_1.c as it is
1642 invalid for the function to be called.
1643 + Made the xRxLock and xTxLock members of the queue structure volatile.
1644 This is probably not necessary, and is included as a precautionary
1646 + Modify the assert() that checks to see if the priority passed into an
1647 xTaskCreate() function is within valid bounds to permit the assert to be
1648 used in the FreeRTOS MPU port.
1649 + The software timer service (daemon) task is now created in a way that
1650 to ensure compatibility with FreeRTOS MPU.
1652 Changes between V7.1.0 and V7.1.1 released May 1 2012
1656 The following ports are brand new:
1659 The following ports have been available as separate downloads for a number
1660 of months, but are now included in the main FreeRTOS download.
1663 + Cortex-M4F GCC (with full floating point support)
1668 The following demos are brand new:
1669 + Renesas RX63N RDK (Renesas compiler)
1671 The following demos have been available as separate downloads for a number
1672 of months, but are now included in the main FreeRTOS download.
1673 + NXP LPC1114 GCC/LPCXpresso
1675 + Infineon XMC4500 GCC/Atollic
1676 + Infineon XMC4500 IAR
1677 + Infineon XMC4500 Keil
1678 + Infineon XMC4500 Tasking
1681 Kernel miscellaneous / maintenance:
1683 + Introduced the portSETUP_TCB() macro to remove the requirement for the
1684 Windows simulator to use the traceTASK_CREATE() macro, leaving the trace
1685 macro available for use by FreeRTOS+Trace (https://www.FreeRTOS.org/trace).
1686 + Added a new trace macro, traceMOVE_TASK_TO_READY_STATE(), to allow future
1687 FreeRTOS+Trace versions to provide even more information to users.
1688 + Updated the FreeRTOS MPU port to be correct for changes that were
1689 introduced in FreeRTOS V7.1.0.
1690 + Introduced the xQueueReset() API function.
1691 + Introduced the xSemaphoreGetMutexHolder() API function.
1692 + Tidy up various port implementations to add the static key word where
1693 appropriate, and remove obsolete code.
1694 + Slight change to the initial stack frame given to the RX600 ports to allow
1695 them to be used in the Eclipse based E2Studio IDE without confusing GDB.
1696 + Correct the alignment given to the initial stack of Cortex-M4F tasks.
1697 + Added a NOP following each DINT instruction on MSP430 devices for strict
1698 conformance with the instructions on using DINT.
1699 + Changed the implementation of thread deletes in the Win32 port to prevent
1700 the port making use of the traceTASK_DELETE() trace macros - leaving this
1701 macro free for use by FreeRTOS+Trace.
1702 + Made some benign changes to the RX600 Renesas compiler port layer to
1703 ensure the code can be built to a library without essential code being
1704 removed by the linker.
1705 + Reverted the change in the name of the uxTaskNumber variable made in
1706 V7.1.0 as it broke the IAR plug-in.
1709 Demo miscellaneous / maintenance:
1711 + The command interpreter has now been formally released as FreeRTOS+CLI,
1712 and been moved out of the main FreeRTOS download, to instead be available
1713 from the FreeRTOS+ Ecosystem site https://www.FreeRTOS.org/plus.
1714 + flash_timer.c/h has been added to the list of standard demo tasks. This
1715 performs the same functionality as the flash.c tasks, but using software
1716 timers in place of tasks.
1717 + Upgraded the PIC32 demo as follows: Changes to how the library functions
1718 are called necessitated by the new compiler version, addition of MPLAB X
1719 project with PIC32MX360, PIC32MX460 and PIC32MX795 configurations,
1720 addition of simply blinky demo, updated FreeRTOSConfig.h to include more
1721 parameters, addition of hook function stubs.
1722 + The MSP430X IAR and CCS demos have been updated to ensure the power
1723 settings are correct for the configured CPU frequency.
1724 + Rowley CrossWorks projects have been updated to correct the "multiple
1725 definition of ..." warnings introduced when the toolchain was updated.
1726 + Updated various FreeRTOSConfig.h header files associated with projects
1727 that build with Eclipse to include a #error statement informing the user
1728 that the CreateProjectDirectoryStructure.bat batch file needs to be
1729 executed before the projects can be opened.
1730 + Renamed directories that included "CCS4" in their name to remove the '4'
1731 and instead just be "CCS". This is because the demo was updated and
1732 tested to also work with later Code Composer Studio versions.
1733 + Updated the TCP/IP periodic timer frequency in numerous uIP demos to be
1734 50ms instead of 500ms.
1736 Changes between V7.0.2 and V7.1.0 released December 13 2011
1740 + Cortex-M4F IAR port.
1741 + Cortex-M4F Keil/RVDS port.
1746 + NXP LPC4350 using the Keil MDK, and demonstrated on a Hitex development
1748 + ST STM32F407 using the IAR Embedded Workbench for ARM, and demonstrated on
1749 the IAR STM32F407ZG-SK starter kit.
1750 + Infineon TriCore TC1782, using the GCC compiler, demonstrated on the
1751 TriBoard TC1782 evaluation board.
1752 + Renesas RX630, using the Renesas compiler and HEW, demonstrated on an
1753 RX630 RSK (Renesas Starter Kit).
1755 Miscellaneous / maintenance:
1757 + Removed all calls to printf() from the K60/IAR Kinetis demo so the project
1758 can execute stand alone - without being connected to the debugger.
1759 + Completed the command interpreter framework. Command handlers now receive
1760 the entire command string, giving them direct access to parameters.
1761 Utility functions are provided to check the number of parameters, and
1762 return parameter sub-strings.
1763 + The previously documented fix for the bug in xTaskResumeFromISR() that
1764 effected (only) ports supporting interrupt nesting has now been
1765 incorporated into the main release.
1766 + The portALIGNMENT_ASSERT_pxCurrentTCB() definition has been added to allow
1767 specific ports to skip the second stack alignment check when a task is
1768 created. This is because the second check is not appropriate for some
1769 ports - including the new TriCore port where the checked pointer does not
1770 actually point to a stack.
1771 + The portCLEAN_UP_TCB() macro has been added to allow port specific clean
1772 up when a task is deleted - again this is required by the TriCore port.
1773 + Various other minor changes to ensure warning free builds on a growing
1774 number of microcontroller and toolchain platforms. This includes a
1775 (benign) correction to the prototype of the
1776 vApplicationStackOverflowHook() definition found in lots of recent demos.
1780 + The legacy trace mechanism has been completely removed - it has been
1781 obsolete for the years since the trace macros were introduced. The
1782 configuration constant configUSE_TRACE_FACILITY is now used to optionally
1783 include additional queue and task information. The additional information
1784 is intended to make the trace mechanism more generic, and allow the trace
1785 output to provide more information. When configUSE_TRACE_FACILITY is set
1787 - the queue structure includes an additional member to hold the queue
1788 type, which can be base, mutex, counting semaphore, binary semaphore
1790 - the queue structure includes an additional member to hold a queue
1791 number. A trace tool can set and query the queue number for its own
1792 purposes. The kernel does not use the queue number itself.
1793 - the TCB structure includes an additional member to hold a task number
1794 number. A trace tool can set and query the task number for its own
1795 purposes. The kernel does not use the task number itself.
1796 + Queues and all types of semaphores are now automatically allocated their
1797 type as they are created.
1798 + Added two new trace macros - traceTASK_PRIORITY_INHERIT() and
1799 traskTASK_PRIORITY_DISINHERIT().
1800 + Updated the traceQUEUE_CREATE_FAILED() macro to take a parameter that
1801 indicates the type of queue, mutex, or semaphore that failed to be
1803 + The position from which traceCREATE_MUTEX() is called has been moved from
1804 after the call to xQueueGenericSend() [within the same function] to before
1805 the call. This ensures the trace events occur in the correct order.
1806 + The value passed into tracePRIORITY_SET() has been corrected for the case
1807 where vTaskPrioritySet() is called with a null parameter.
1809 Changes between V7.0.1 and V7.0.2 released September 20 2011
1813 + The official FreeRTOS Renesas RX200 port and demo application have been
1814 incorporated into the main FreeRTOS zip file download.
1815 + The official FreeRTOS Renesas RL78 port and demo application have been
1816 incorporated into the main FreeRTOS zip file download.
1817 + The official FreeRTOS Freescale Kinetis K60 tower demo application has
1818 been incorporated into the main FreeRTOS zip file download. This includes
1819 an embedded web server example.
1820 + A new Microblaze V8 port layer has been created to replace the older, now
1821 deprecated, port layer. The V8 port supports V8.x of the Microblaze IP,
1822 including exceptions, caches, and the floating point unit. A new
1823 Microblaze demo has also been added to demonstrate the new Microblaze V8
1824 port layer. The demo application was created using V13.1 of the Xilinx
1825 EDK, and includes a basic embedded web server that uses lwIP V1.4.0.
1826 + The official FreeRTOS Fujitsu FM3 MB9A310 demo application has been
1827 incorporated into the main FreeRTOS zip file download. Projects are
1828 provided for both the IAR and Keil toolchains.
1833 + xTaskGetIdleTaskHandle() has been added.
1834 + xTaskGetTimerDaemonTaskHandle() has been added.
1835 + pcTaskGetTaskName() has been added.
1836 + vSemaphoreDelete() macro has been added to make it obvious how to delete
1837 a semaphore. In previous versions vQueueDelete() had to be used.
1838 + vTaskCleanUpResources() has been removed. It has been obsolete for a
1840 + portPOINTER_SIZE_TYPE has been introduced to prevent compiler warnings
1841 being generated when the size of a pointer does not match the size of
1842 the stack type. This will (has already) be used in new ports, but will
1843 not be retrofitted to existing ports until the existing port itself is
1846 Other updates and news:
1848 + The core files have all been modified to tighten the coding standard even
1849 further. These are style, not functional changes.
1850 + All ARM7 port layers have been slightly modified to prevent erroneous
1851 assert() failures when tasks are created and configASSERT() is defined.
1852 + All ARM IAR projects have been updated to build with the latest V6.2.x
1853 versions of the IAR Embedded Workbench for ARM tools (EWARM). This was
1854 necessary due to a change in the way EWARM uses the CMSIS libraries.
1855 + The PIC32 port layer has been updated in preparation for V2 of the C32
1857 + The old Virtex-4 Microblaze demo has been marked as deprecated. Please
1858 use the brand new Spartan-6 port and demo in its place.
1859 + The bones of a new generic command interpreter is located in
1860 FreeRTOS/Demo/Common/Utils/CommandInterpreter.c. This is still a work in
1861 progress, and not documented. It is however already in use. It will be
1862 documented in full when the projects that are already using it are
1864 + A couple of new standard demos have been included. First, a version of
1865 flop.c called sp_flop.c. This is similar to flop.c, but uses single
1866 precision floats in place of double precision doubles. This allows the
1867 for testing ports to processors that have only single precision floating
1868 point units, and revert to using emulated calculations whenever a double
1869 is used. Second, comtest_strings.c has been included to allow the test
1870 of UART drivers when an entire string is transmitted at once. The
1871 previous comtest.c only used single character transmission and reception.
1872 + lwIP V1.4.0 is now included in the FreeRTOS/Demo/Common directory, and
1873 used by a couple of new demos.
1875 Changes between V7.0.0 and V7.0.1 released May 13 2011
1877 + Added a Fujitsu FM3 demo application for both the IAR and Keil tool
1879 + Added a SmartFusion demo application for all of the IAR, Keil and
1880 SoftConsole (GCC/Eclipse) tool chains.
1881 + Updated the RX600 port and demo applications to take into account the
1882 different semantics required when using the latest (V1.0.2.0) version of
1883 the Renesas compiler.
1884 + Modified the RX600 Ethernet driver slightly to make it more robust under
1885 heavy load, and updated the uIP handling task to make use of the FreeRTOS
1887 + Slightly changed the PIC32 port layer to move an ehb instruction in line
1888 with the recommendations of the MIPS core manual, and ensure 8 byte stack
1889 alignment is truly always obtained.
1890 + Changed the behaviour when tasks are suspended before the scheduler has
1891 been started. Before, there needed to be at least one task that was not
1892 in the suspended state. This is no longer the case.
1894 Changes between V6.1.1 and V7.0.0 released April 8 2011
1896 FreeRTOS V7.0.0 is backward compatible with FreeRTOS V6.x.x
1900 + Introduced a new software timer implementation.
1901 + Introduced a new common demo application file to exercise the new timer
1903 + Updated the Win32/MSVC simulator project to include the new software timer
1904 demo tasks and software timer tick hook test. Much simpler software timer
1905 demonstrations are included in the demo projects for both of the new ports
1906 (MSP430X with CCS4 and STM32 with TrueStudio).
1907 + Various enhancements to the kernel implementation in tasks.c. These are
1908 transparent to users and do not effect the pre-existing API.
1909 + Added calls to configASSERT() within the kernel code. configASSERT() is
1910 functionally equivalent to the standard C assert() macro, but does not
1911 rely on the compiler providing assert.h.
1915 + Updated the MSP430X IAR port and demo project to include support for the
1916 medium memory model.
1917 + Added a demo project for the MSP430X that targets the MSP430X Discovery
1918 board and uses the Code Composer Studio 4 tools. This demo includes use
1919 of the new software timer implementation.
1920 + Added an STM32F100RB demo project that targets the STM32 Discovery Board
1921 and uses the TrueStudio Eclipse based IDE from Atollic.
1922 + Removed some compiler warnings from the PSoC demo application.
1923 + Updated the PIC32 port layer to ensure the
1924 configMAX_SYSCALL_INTERRUPT_PRIORITY constant works as expected no matter
1925 what its value is (within the valid range set by the microcontroller
1927 + Updated the PIC24, dsPIC and PIC32 projects so they work with the latest
1928 MPLAB compiler versions from Microchip.
1929 + Various cosmetic changes to prepare for a standards compliance statement
1930 that will be published after the software release.
1933 Changes between V6.1.0 and V6.1.1 released January 14 2011
1935 + Added two new Windows simulator ports. One uses the free Microsoft Visual
1936 Studio 2010 express edition, and the other the free MingW/Eclipse
1937 environment. Demo projects are provided for both.
1938 + Added three demo projects for the PSoC 5 (CYAC5588). These are for the
1939 GCC, Keil, and RVDS build tools, and all use the PSoC Creator IDE.
1940 + Added a demo for the low power STM32L152 microcontroller using the IAR
1942 + Added a new port for the MSP430X core using the IAR Embedded Workbench.
1943 + Updated all the RX62N demo projects that target the Renesas Demonstration
1944 Kit (RDK) to take into account the revered LED wiring on later hardware
1945 revisions, and the new J-Link debug interface DLL.
1946 + Updated all the RX62N demo projects so the IO page served by the example
1947 embedded web server works with all web browsers.
1948 + Updated the Red Suite projects to work with the up coming Red Suite
1949 release, and to use a more recent version of the CMSIS libraries.
1950 + Added the traceTAKE_MUTEX_RECURSIVE_FAILED() trace macro.
1951 + Removed the (pointless) parameter from the traceTASK_CREATE_FAILED()
1953 + Introduced the portALT_GET_RUN_TIME_COUNTER_VALUE() macro to compliment
1954 the already existing portGET_RUN_TIME_COUNTER_VALUE(). This allows for
1955 more flexibility in how the time base for the run time statistics feature
1957 + Added a "cpsie i" instruction before the "svc 0" instruction used to start
1958 the scheduler in each of the Cortex M3 ports. This is to ensure that
1959 interrupts are globally enabled prior to the "svc 0" instruction being
1960 executed in cases where interrupts are left disabled by the C start up
1962 + Slight optimisation in the run time stats calculation.
1964 Changes between V6.0.5 and V6.1.0 released October 6 2010
1966 + Added xTaskGetTickCountFromISR() function.
1967 + Modified vTaskSuspend() to allow tasks that have just been created to be
1968 immediately suspended even when the kernel has not been started. This
1969 allows them to effectively start in the Suspended state - a feature that
1970 has been asked for on numerous occasions to assist with initialisation
1972 + Added ports for the Renesas RX62N using IAR, GCC and Renesas tool suites.
1973 + Added a STM32F103 demo application that uses the Rowley tools.
1974 + Under specific conditions xFreeBytesRemaining within heap_2.c could end up
1975 with an incorrect value. This has been fixed.
1976 + xTaskCreateGeneric() has a parameter that can be used to pass the handle
1977 of the task just created out to the calling task. The assignment to this
1978 parameter has been moved to ensure it is assigned prior to the newly
1979 created having any possibility of executing. This takes into account the
1980 case where the assignment is made to a global variable that is accessed by
1981 the newly created task.
1982 + Fixed some build time compiler warnings in various FreeTCPIP (based on
1984 + Fixed some build time compiler warnings in Demo/Common/Minimal/IntQueue.c.
1986 Changes between V6.0.4 and V6.0.5 released May 17 2010
1988 + Added port and demo application for the Cortus APS3 processor.
1990 Changes between V6.0.3 and V6.0.4 released March 14 2010
1992 + All the contributed files that were located in the Demo/Unsupported_Demos
1993 directory have been removed. These files are instead now available in the
1994 new Community Contributions section of the FreeRTOS website. See
1995 https://www.FreeRTOS.org/RTOS-contributed-ports.html
1996 + The project file located in the Demo/CORTEX_STM32F107_GCC_Rowley directory
1997 has been upgraded to use V2.x of the Rowley Crossworks STM32 support
1999 + An initial Energy Micro EFM32 demo has been included. This will be
2000 updated over the coming months to make better use of the low power modes
2003 Changes between V6.0.2 and V6.0.3 released February 26 2010
2005 + SuperH SH7216 (SH2A-FPU) port and demo application added.
2006 + Slight modification made to the default implementation of
2007 pvPortMallocAligned() and vPortFreeAligned() macros so by default they
2008 just call pvPortMalloc() and vPortFree(). The macros are only needed to
2009 be defined when a memory protection unit (MPU) is being used - and then
2010 only depending on other configuration settings.
2012 Changes between V6.0.1 and V6.0.2 released January 9th 2010
2014 + Changed all GCC ARM 7 ports to use 0 as the SWI instruction parameter.
2015 Previously the parameter was blank and therefore only an implicit 0 but
2016 newer GCC releases do not permit this.
2017 + Updated IAR SAM7S and SAM7X ports to work with IAR V5.40.
2018 + Changed the stack alignment requirement for PIC32 from 4 bytes to 8 bytes.
2019 + Updated prvListTaskWithinSingleList() is it works on processors where the
2020 stack grows up from low memory.
2021 + Corrected some comments.
2022 + Updated the startup file for the RVDS LPC21xx demo.
2024 Changes between V6.0.0 and V6.0.1 released November 15th 2009
2026 + Altered pxPortInitialiseStack() for all Cortex-M3 ports to ensure the
2027 stack pointer is where the compiler expects it to be when a task first
2030 The following minor changes only effect the Cortex-M3 MPU port:
2032 + portRESET_PRIVILEGE() assembly macro updated to include a clobber list.
2033 + Added prototypes for all the privileged function wrappers to ensure no
2034 compile time warnings are generated no matter what the warning level
2036 + Corrected the name of portSVC_prvRaisePrivilege to
2037 portSVC_RAISE_PRIVILEGE.
2038 + Added conditional compilation into xTaskGenericCreate() to prevent some
2039 compilers issuing warnings when portPRIVILEGE_BIT is defined as zero.
2042 Changes between V5.4.2 and V6.0.0 released October 16th 2009
2044 FreeRTOS V6 is backward compatible with FreeRTOS V5.x.
2048 + FreeRTOS V6 is the first version to include memory protection unit (MPU)
2049 support. Two ports now exist for the Cortex M3, the standard FreeRTOS
2050 which does not include MPU support, and FreeRTOS-MPU which does.
2051 + xTaskCreateRestricted() and vTaskAllocateMPURegions() API functions added
2052 in support of FreeRTOS-MPU.
2053 + Wording for the GPL exception has been (hopefully) clarified. Also the
2054 license.txt file included in the download has been fixed (the previous
2055 version contained some corruption).
2059 + New API function xPortGetFreeHeapSize() added to heap_1.c and heap_2.c.
2060 + ARM7 GCC demo interrupt service routines wrappers have been modified to
2061 call the C portion using an __asm statement. This prevents the function
2062 call being inlined at higher optimisation levels.
2063 + ARM7 ports now automatically set the THUMB bit if necessary when
2064 setting up the initial stack of a task - removing the need for
2065 THUMB_INTERWORK to be defined. This also allows THUMB mode and ARM mode
2066 tasks to be mixed more easily.
2067 + All ARM7/9 ports now have portBYTE_ALIGNMENT set to 8 by default.
2068 + Various demo application project files have been updated to be up to date
2069 with the latest IDE versions.
2070 + The linker scripts used with command line GCC demos have been updated to
2071 include an eh_frame section to allow their use with the latest Yagarto
2072 release. Likewise the demo makefiles have been updated to include
2073 command line options to reduce or eliminate the eh_frame section all
2075 + The definition of portBYTE_ALIGNMENT_MASK has been moved out of the
2076 various memory allocation files and into the common portable.h header
2078 + Removed unnecessary use of portLONG, portSHORT and portCHAR.
2079 + Added LM3Sxxxx demo for Rowley CrossWorks.
2080 + Posix simulator has been upgraded - see the corresponding WEB page on the
2084 Changes between V5.4.1 and V5.4.2 released August 9th 2009
2086 + Added a new port and demo app for the Altera Nios2 soft core.
2087 + Added LPC1768 demo for IAR.
2088 + Added a USB CDC demo to all LPC1768 demos (Code Red, CrossWorks and IAR).
2089 + Changed clock frequency of LPC1768 demos to 99MHz.
2091 Changes between V5.4.0 and V5.4.1 released July 25th 2009
2093 + New hook function added. vApplicationMallocFailedHook() is (optionally)
2094 called if pvPortMalloc() returns NULL.
2095 + Additional casting added to xTaskCheckForTimeOut(). This prevents
2096 problems that can arise should configUSE_16_BIT_TICKS be set to 1 on a
2097 32 bit architecture (which would probably be a mistake, anyway).
2098 + Corrected the parameter passed to NVIC_SetPriority() to set the MAC
2099 interrupt priority in both LPC1768 demos.
2100 + Decreased the default setting of configMINIMAL_STACK_SIZE in the PIC32
2101 demo application to ensure the heap space was not completely consumed
2102 before the scheduler was started.
2104 Changes between V5.3.1 and V5.4.0 released July 13th 2009
2106 + Added Virtex5 / PPC440 port and demos.
2107 + Replaced the LPC1766 Red Suite demo with an LPC1768 Red Suite demo. The
2108 original demo was configured to use engineering samples of the CPU. The
2109 new demo has an improved Ethernet driver.
2110 + Added LPC1768 Rowley demo with zero copy Ethernet driver.
2111 + Reworked byte alignment code to ensure 8 byte alignment works correctly.
2112 + Set configUSE_16_BIT_TICKS to 0 in the PPC405 demo projects.
2113 + Changed the initial stack setup for the PPC405 to ensure the small data
2114 area pointers are setup correctly.
2116 Changes between V5.3.0 and V5.3.1 released June 21st 2009
2118 + Added ColdFire V1 MCF51CN128 port and WEB server demo.
2119 + Added STM32 Connectivity Line STM32107 Cortex M3 WEB server demo.
2120 + Changed the Cortex M3 port.c asm statements to __asm so it can be
2121 compiled using Rowley CrossWorks V2 in its default configuration.
2122 + Updated the Posix/Linux simulator contributed port.
2124 Changes between V5.2.0 and V5.3.0 released June 1st 2009
2128 + Added new (optional) feature that gathers statistics on the amount of CPU
2129 time used by each task.
2130 + Added a new demo application for the Atmel AT91SAM3U Cortex-M3 based
2132 + Added a new demo application for the NXP LPC1766 Cortex-M3 based
2134 + Added a contributed port/demo that allows FreeRTOS to be 'simulated' in a
2138 + Updated the Stellaris uIP WEB server demos to include the new run time
2139 statistics gathering feature - and include a served WEB page that
2140 presents the information in a tabular format.
2141 + Added in the lwIP port layer for the Coldfire MCF52259.
2142 + Updated the CrossWorks LPC2368 WEB server to include an image in the
2144 + Changed some of the timing in the initialisation of the LPC2368 MAC to
2145 permit its use on all part revisions.
2146 + Minor modifications to the core uIP code to remove some compiler warnings.
2147 + Added xTaskGetApplicationTaskTag() function and updated the OpenWatcom
2148 demo to make use of the new function.
2149 + Added contributed demos for AVR32 AP7000, STM32 Primer 2 and STM32 using
2151 + Heap_1.c and Heap_2.c used to define structures for the purpose of data
2152 alignment. These have been converted to unions to save a few bytes of
2153 RAM that would otherwise be wasted.
2154 + Remove the call to strncpy() used to copy the task name into the TCB when
2155 the maximum task name is configured to be 1 byte long.
2157 Changes between V5.1.2 and V5.2.0 released March 14th 2009
2159 + Optimised the queue send and receive functions (also used by semaphores).
2160 + Replaced the standard critical sections used to protect BIOS calls in the
2161 PC port to instead use scheduler locks. This is because the BIOS calls
2162 always return with interrupts enabled.
2163 + Corrected unclosed comments in boot.s.
2165 Changes between V5.1.1 and V5.1.2 released February 9th 2009
2167 + Added NEC V850ES port and demo.
2168 + Added NEC 78K0R port and demo.
2169 + Added MCF52259 port and demo.
2170 + Added the AT91SAM9XE port and demo.
2171 + Updated the MCF52233 FEC driver to work around a silicon bug that
2172 prevents the part auto negotiating some network parameters.
2173 + Minor modifications to the MCF52233 makefile to permit it to be used
2175 + Updated the STM32 primer files to allow them to be built with the latest
2176 version of the RIDE tools.
2177 + Updated the threads.js Java script used for kernel aware debugging in
2178 the Rowley CrossWorks IDE.
2181 Changes between V5.1.0 and V5.1.1 released November 20, 2008
2183 + Added Coldfire MCF52233 WEB server demo using GCC and Eclipse.
2184 + Added IAR MSP430 port and demo.
2185 + Corrected several compiler time issues that had crept in as tool versions
2187 + Included FreeRTOS-uIP - a faster uIP. This is not yet complete.
2189 Changes between V5.0.4 and V5.1.0 released October 24, 2008
2191 + Added a new port and demo application for the ColdFire V2 core using the
2192 CodeWarrior development tools.
2193 + Replaced the ARM7 demo that used the old (and now no longer supported)
2194 Keil compiler with a new port that uses the new Keil/RVDS combo.
2195 + Stack overflow checking now works for stacks that grow up from low
2196 memory (PIC24 and dsPIC).
2197 + BUG FIX - set the PIC32 definition of portSTACK_GROWTH to the correct
2199 + MSP430 port layers have been updated to permit tasks to place the
2200 microcontroller into power down modes 1 to 3. The demo applications have
2201 likewise been updated to demonstrate the new feature.
2202 + Replaced the two separate MSP430/Rowley port layers with a single and more
2204 + Added more contributed ports, including ports for NEC and SAM9
2206 + Changed the linker script used in the LPC2368 Eclipse demo.
2208 Changes between V5.0.3 and V5.0.4 released September 22, 2008
2210 + Completely re-written port for ColdFire GCC.
2211 + Bug fix: All Cortex M3 ports have a minor change to the code that sets
2212 the pending interrupt.
2213 + Some header files require that FreeRTOS.h be included prior to their
2214 inclusion. #error message have been added to all such header file
2215 informing users to the cause of the compilation error should the headers
2216 not be included in the correct order.
2218 Changes between V5.0.2 and V5.0.3 released July 31, 2008
2220 Changes relating to the Cortex M3:
2222 + Added configMAX_SYSCALL_INTERRUPT_PRIORITY usage to all the Cortex M3
2223 ports and demos. See the port documentation pages on the FreeRTOS.org
2224 WEB site for full usage information.
2225 + Improved efficiency of Cortex M3 port even further.
2226 + Ensure the Cortex M3 port works no matter where the vector table is
2228 + Added the IntQTimer demo/test tasks to a demo project for each CM3 port
2229 (Keil, GCC and IAR) to test the new configMAX_SYSCALL_INTERRUPT_PRIORITY
2231 + Added the mainINCLUDE_WEB_SERVER definition to the LM3SXXXX IAR and Keil
2232 projects to allow the WEB server to be conditionally excluded from the
2233 build and therefore allow use of the KickStart (code size limited)
2238 + Moved the PIC24 and dsPIC versions of vPortYield() from the C file to
2239 an assembly file to allow use with all MPLAB compiler versions. This also
2240 allows the omit-frame-pointer optimisation to be turned off.
2242 Changes between V5.0.0 and V5.0.2 released May 30, 2008
2244 + Updated the PIC32 port to allow queue API calls to be used from
2245 interrupts above the kernel interrupt priority, and to allow full
2246 interrupt nesting. Task stack usages has also been reduced.
2247 + Added a new PowerPC port that demonstrates how the trace macros can be
2248 used to allow the use of a floating point co-processor. The
2249 traceTASK_SWITCHED_OUT() and traceTASK_SWITCHED_INT() macros are used to
2250 save and restore the floating point context respectively for those tasks
2251 that actually use floating point operations.
2252 + BUG FIX: The first PPC405 port contained a bug in that it did not leave
2253 adequate space above the stack for the backchain to be saved when a task
2254 started to execute for the first time.
2255 + Updated queue.c to add in the means to allow interrupt nesting and for
2256 queue API functions to be called from interrupts that have a priority
2257 above the kernel priority. This is only supported on PIC32 ports thus
2259 + Fixed the compiler warnings that were generated when the latest version
2261 + Remove all inline usage of 'inline' from the core kernel code.
2262 + Added the queue registry feature. The queue registry is provided as a
2263 means for kernel aware debuggers to locate queue definitions. It has no
2264 purpose unless you are using a kernel aware debugger. The queue registry
2265 will only be used when configQUEUE_REGISTRY_SIZE is greater than zero.
2266 + Added the ST Cortex-M3 drivers into the Demo/Common/Drivers directory to
2267 prevent them from having to be included in multiple demos.
2268 + Added a Keil STM32 demo application.
2269 + Changed the blocktim.c test files as it is no longer legitimate for all
2270 ports to call queue API functions from within a critical section.
2271 + Added the IntQueue.c test file to test the calling of queue API functions
2272 from different interrupt priority levels, and test interrupt nesting.
2274 Changes between V5.0.0 and V5.0.1
2276 + V5.0.1 was a customer specific release.
2278 Changes between V4.8.0 and V5.0.0 released April 15, 2008
2280 *** VERY IMPORTANT INFORMATION ON UPGRADING TO FREERTOS.ORG V5.0.0 ***
2282 The parameters to the functions xQueueSendFromISR(), xQueueSendToFrontFromISR(),
2283 xQueueSendToBackFromISR() and xSemaphoreGiveFromISR() have changed. You must
2284 update all calls to these functions to use the new calling convention! Your
2285 compiler might not issue any type mismatch warnings!
2290 + Support added for the new Luminary Micro LM3S3768 and LM3S3748 Cortex-M3
2292 + New task hook feature added.
2293 + PowerPC demo updated to use version 10.1 of the Xilinx EDK.
2294 + Efficiency gains within the PIC32 port layer.
2296 Changes between V4.7.2 and V4.8.0 released March 26 2008
2298 + Added a Virtex4 PowerPC 405 port and demo application.
2299 + Added optional stack overflow checking and new
2300 uxTaskGetStackHighWaterMark() function.
2301 + Added new xQueueIsQueueEmptyFromISR(), xQueueIsQueueFullFromISR() and
2302 uxQueueMessagesWaitingFromISR() API functions.
2303 + Efficiency improvements to the Cortex-M3 port layer. NOTE: This
2304 requires that an SVC handler be installed in the application.
2305 + Efficiency improvements to the queue send and receive functions.
2306 + Added new trace macros. These are application definable to provide
2307 a flexible trace facility.
2308 + Implemented the configKERNEL_INTERRUPT_PRIORITY within the Keil Cortex
2309 M3 port layer (bringing it up to the same standard as the IAR and GCC
2311 + Ports that used the arm-stellaris-eabi-gcc tools have been converted to
2312 use the arm-non-eabi-gcc tools.
2314 Changes between V4.7.1 and V4.7.2 released February 21, 2008
2316 + Added Fujitsu MB91460 port and demo.
2317 + Added Fujitsu MB96340 port and demo.
2318 + Tidied up the capitalisation of include files to facilitate builds on
2320 + Removed some redundant casting that was generating warnings - but was
2321 included to remove warnings on other compilers.
2323 Changes between V4.7.0 and V4.7.1 released February 3, 2008
2325 + Updated all IAR ARM projects to use V5.11 of the IAR Embedded Workbench
2327 + Introduced recursive semaphore feature.
2328 + Updated LPC2368 demos to take into account silicon bugs in old chip
2330 + Updated STR9 uIP port to manually set the net mask and gateway addresses.
2331 + Updating demos to allow more to run with the co-operative scheduler.
2332 + Fixed co-operative scheduler behaviour upon the occurrence of a tick
2333 interrupt while the scheduler was suspended.
2334 + Updated documentation contained within semphr.h.
2335 + ARM7 GCC ports no longer use the IRQ attribute.
2337 Changes between V4.6.1 and V4.7.0 released December 6, 2007
2339 + Introduced the counting semaphore macros and demo source files. The
2340 Open Watcom PC project has been updated to include the new demo. See
2341 the online documentation for more information.
2342 + Introduced the 'alternative' queue handling API and demo source files.
2343 The Open Watcom PC project has been updated to include the new demo
2344 source files. See the online documentation for more information.
2345 + Added AT91SAM7X Eclipse demo project.
2346 + Added the STM32 primer demo project for the GCC compiler and Ride IDE.
2347 + Removed the .lock files that were mistakenly included in the V4.6.1
2350 Changes between V4.6.0 and V4.6.1 released November 5 2007
2352 + Added support for the MIPS M4K based PIC32.
2353 + Added 'extern "C"' to all the header files to facilitate use with C++.
2355 Changes between V4.5.0 and V4.6.0 released October 28 2007
2357 + Changed the method used to force a context switch within an ISR for the
2358 ARM7/9 GCC ports only. The portENTER_SWITCHING_ISR() and
2359 portEXIT_SWITCHING_ISR() macros are no longer supported. This is to
2360 ensure correct behaviour no matter which GCC version is used, with or
2361 without the -fomit-frame-pointer option, and at all optimisation levels.
2362 + Corrected the prototype for xQueueGenericSend() within queue.h.
2364 Changes between V4.4.0 and V4.5.0 released September 17 2007
2366 + Added the xQueueSendToFront(), xQueueSendToBack() and xQueuePeek()
2367 functionality. These should now be used in preference to the old
2368 xQueueSend() function - which is maintained for backward compatibility.
2369 + Added Mutex functionality. The behaviour of mutexes is subtly different
2370 to the already existing binary semaphores as mutexes automatically
2371 include a priority inheritance mechanism.
2372 + Added the GenQTest.c and QPeek.c to test and demonstrate the behaviour
2373 of the new functionality.
2374 + Updated the LM3Sxxxx and PC ports to include the new GenQTest.c and
2376 + Updated the GCC port for the Cortex M3 to include the
2377 configKERNEL_INTERRUPT_PRIORITY functionality. This was previously only
2378 included in the IAR port.
2379 + Optimised the GCC and IAR port layer code - specifically the context
2381 + Consolidated the LM3Sxxxx EK demos for all development tools into a
2382 single project that automatically detects which version of the EK the
2383 application is executing on.
2384 + Added Eclipse support for LM3Sxxxx evaluation kits.
2385 + Added Eclipse support for the Keil LPC2368 evaluation kit.
2386 + Added the Demo/Drivers directory to hold code that is common to multiple
2387 demo application projects.
2388 + Included some minor bug fixes in the uIP 1.0 code.
2389 + Added an lwIP demo for the STR9 - thanks ST for assistance.
2390 + Updated the AVR32 port to ensure correct behaviour with full compiler
2392 + Included binaries for OpenOCD FTDI and parallel port interfaces.
2394 Changes between V4.4.0 and V4.3.1 released July 31, 2007
2396 + Added AVR32 UC3B demo application.
2397 + Updated AVR32 UC3A port and demo applications.
2398 + Added IAR lwIP demo for AVR32 UC3A.
2399 + Updated listGET_OWNER_OF_NEXT_ENTRY() to assist compiler optimisation
2400 (thanks Niu Yong for making the suggestion).
2401 + Added xTaskGetSchedulerState() API function.
2402 + BUG FIX: Corrected behaviour when tasks that are blocked indefinitely
2403 have their block time adjusted (within xQueueSend() and xQueueReceive()),
2404 and are the subject of a call the vTaskResume() when they are not
2405 actually in the Suspended state (thanks Dan Searles for reporting the
2409 Changes between V4.3.0 and V4.3.1 released June 11, 2007
2411 + Added STMicroelectronics STM32 Cortex-M3 demo application.
2412 + Updated ustdlib.c for the GCC LM3S6965 demo.
2414 Changes between V4.2.1 and V4.3.0 released June 5, 2007
2416 + Introduced configKERNEL_INTERRUPT_PRIORITY to the IAR Cortex-M3, PIC24
2417 and dsPIC ports. See the LM3S6965 and PIC24 demo application
2418 documentation pages for more information.
2419 + Updated the PIC24 and dsPIC demos to build with V3.0 of the PIC30 GCC
2420 tools, and changed the demo applications.
2421 + Added demos for the new Ethernet and CAN enabled Luminary Micro Stellaris
2423 + Corrected bug in uIP the demos that prevented frames of approximately 1480
2424 bytes and over from being transmitted.
2425 + Included the LPC2368/uIP/Rowley demo into the main FreeRTOS.org
2427 + Update to WizC PIC18 port to permit its use with version 14 of the
2428 compiler. Thanks Marcel!
2430 Changes between V4.2.1 and V4.2.0 released April 2, 2007
2432 + Added AVR32 AT32UC3A ports for GCC and IAR.
2433 + Added -fomit-frame-pointer option to lwIP SAM7X demo makefile.
2434 + Moved location of call to LCD_Init() in STR9 demo to ensure it is only
2435 called after the scheduler has been started.
2437 Changes between V4.1.3 and V4.2.0 released February 8, 2007
2439 + Changes to both task.c and queue.c as a result of testing performed on
2440 the SafeRTOS code base.
2441 + Added Cortex-M3 LM3S811 demos for GCC and IAR tools.
2443 Changes between V4.1.2 and V4.1.3 released November 19, 2006
2445 + Added STR750 ARM7 port using the Raisonance RIDE/GCC tools.
2446 + Added -fomit-frame-pointer option to Rowley ARM7 demos as work around
2447 to GCC bug at some optimisation levels.
2448 + Altered the way the heap is defined in the LM3S811 Keil demo to prevent
2449 the RAM usage from counting toward the code size limit calculation.
2450 + CO-ROUTINE BUG FIX: Removed the call to prvIsQueueEmpty from within
2451 xQueueCRReceive as it exited with interrupts enabled. Thanks Paul Katz.
2452 + Tasks that block on events with a timeout of portMAX_DELAY are now
2453 blocked indefinitely if configINCLUDE_vTaskSuspend is defined.
2454 Previously portMAX_DELAY was just the longest block time possible. This
2455 is still the case if configINCLUDE_vTaskSuspend is not defined.
2456 + Minor changes to some demo application files.
2458 Changes between V4.1.1 and V4.1.2 released October 21, 2006
2460 + Added 16bit PIC ports and demos.
2461 + Added STR750 port and demo.
2464 Changes between V4.1.0 and V4.1.1 released September 24, 2006
2466 + Added the Luminary Micro Stellaris LM3S811 demo application.
2468 Changes between V4.0.5 and V4.1.0 released August 28, 2006
2470 + Prior to V4.1.0, under certain documented circumstances, it was possible
2471 for xQueueSend() and xQueueReceive() to return without having completed
2472 and without their block time expiring. The block time effectively
2473 stated a maximum block time, and the return value of the function needed
2474 to be checked to determine the reason for returning. This is no longer
2475 the case as the functions will only return once the block time has
2476 expired or they are able to complete their operation. It is therefore no
2477 longer necessary to wrap calls within loops.
2478 + Changed the critical section handling in the IAR AVR port to correct the
2479 behaviour when used with later compiler versions.
2480 + Added the LPC2138 CrossWorks demo into the zip file. Previously this was
2481 only available as a separate download.
2482 + Modified the AVR demo applications to demonstrate the use of co-routines.
2484 Changes between V4.0.4 and V4.0.5 released August 13, 2006
2486 + Introduced API function xTaskResumeFromISR(). Same functionality as
2487 xTaskResume(), but can be called from within an interrupt service routine.
2488 + Optimised vListInsert() in the case when the wake time is the maximum
2490 + Bug fix: The 'value' of the event list item is updated when the priority
2491 of a task is changed. Previously only the priority of the TCB itself was
2493 + vTaskPrioritySet() and vTaskResume() no longer use the event list item.
2494 This has not been necessary since V4.0.1 when the xMissedYield handling
2496 + Lowered the PCLK setting on the ARM9 STR9 demo from 96MHz to 48MHz.
2497 + When ending the scheduler - do not try to attempt a context switch when
2498 deleting the current task.
2499 + SAM7X EMAC drivers: Corrected the Rx frame length mask when obtaining
2500 the length from the rx descriptor.
2503 Changes between V4.0.3 and V4.0.4 released June 22, 2006
2505 + Added a port and demo application for the STR9 ARM9 based processors from
2507 + Slight optimisation to the vTaskPrioritySet() function.
2508 + Included the latest uIP version (1.0) in the demo/common/ethernet
2511 Changes between V4.0.2 and V4.0.3 released June 7, 2006
2513 + Added a port and demo application for the Cortex-M3 target using the IAR
2515 + The ARM Cortex-m3 Rowley projects have been updated to use V1.6 of the
2517 + The heap size defined for the lwIP Rowley demo has been reduced so that
2518 the project will link correctly when using the command line GCC tools
2519 also. The makefile has also been modified to allow debugging.
2520 + The lwIP Rowley demo not includes a 'kernel aware' debug window.
2521 + The uIP Rowley project has been updated to build with V1.6 of CrossWorks.
2522 + The second set of tasks in the blockQ demo were created the wrong way
2523 around (inconsistent to the description in the file). This has been
2526 Changes between V4.0.1 and V4.0.2 released May 28, 2006
2528 + Port and demo application added for the Tern Ethernet Engine controller.
2529 + Port and demo application added for MC9S12 using GCC, thanks to
2530 Jefferson "imajeff" Smith.
2531 + The function vTaskList() now suspends the scheduler rather than disabling
2532 interrupts during the creation of the task list.
2533 + Allow a task to delete itself by passing in its own handle. Previously
2534 this could only be done by passing in NULL.
2535 + Corrected the value passed to the WDG_PeriodValueConfig() library
2536 function in the STR71x demo.
2537 + The tick hook function is now called only within a tick isr. Previously
2538 it was also called when the tick function was called during the scheduler
2540 + The EMAC driver in the SAM7X lwIP demo has been made more robust as per
2541 the thread: https://sourceforge.net/forum/message.php?msg_id=3714405
2542 + In the PC ports: Add function prvSetTickFrequencyDefault() to set the
2543 DOS tick back to its proper value when the scheduler exits. Thanks
2545 + In the Borland x86 ports there was a mistake in the portFIRST_CONTEXT
2546 macro where the BP register was not popped from the stack correctly. The
2547 BP value would never get used so this did not cause a problem, but it has
2548 been corrected all the same.
2551 Changes between V4.0.0 and V4.0.1 released April 7 2006
2553 + Improved the ARM CORTEX M3 ports so they now only have to service
2555 + Added a Luminary Micro port and demo for use with Rowley CrossWorks.
2556 + Added the xMissedYield handling to tasks.c.
2558 Changes between V3.2.4 and V4.0.0
2562 + Added new RTOS port for Luminary Micros ARM CORTEX M3 microcontrollers.
2563 + Added new co-routine functionality.
2565 Other kernel changes:
2567 + An optional tick hook call is now included in the tick function.
2568 + Introduced the xMiniListItem structure and removed the list pxHead
2569 member in order to reduce RAM usage.
2570 + Added the following definitions to the FreeRTOSConfig.h file included
2573 configUSE_CO_ROUTINES
2574 configMAX_CO_ROUTINE_PRIORITIES
2575 + The volatile qualification has been changed on the list members to allow
2576 the task.c code to be tidied up a bit.
2577 + The scheduler can now be started even if no tasks have been created!
2578 This is to allow co-routines to run when there are no tasks.
2579 + A task being woken by an event will now preempt the currently running task
2580 even if its priority is only equal to the currently running task.
2582 Port and demo application changes:
2584 + Updated the WinAVR demo to compile with the latest version of WinAVR
2585 with no warnings generated.
2586 + Changed the WinAVR makefile to make chars signed - needed for the
2587 co-routine code if BaseType_t is set to char.
2588 + Added new demo application file crflash.c. This demonstrates co-routine
2589 functionality including passing data between co-routines.
2590 + Added new demo application file crhook.c. This demonstrates co-routine
2591 and tick hook functionality including passing data between and ISR and
2593 + Some NOP's were missing following stmdb{}^ instructions in various ARM7
2594 ports. These have been added.
2595 + Updated the Open Watcom PC demo project to include the crflash and crhook
2596 demo co-routines as an example of their use.
2597 + Updated the H8S demo to compile with the latest version of GCC.
2598 + Updated the SAM7X EMAC drivers to take into account the hardware errata
2599 regarding lost packets.
2600 + Changed the default MAC address used by some WEB server demos as the
2601 original addresses used was not liked by some routers.
2602 + Modified the SAM7X/IAR startup code slightly to prevent it hanging on
2603 some systems when the code is executed using a j-link debugger. The
2604 j-link macro file configures the PLL before the code executes so
2605 attempting to configure it again in the startup code was causing a
2606 problem for some user. Now a check is performed first to see if the
2607 PLL is already set up.
2608 + GCC port now contain all assembler code in a single asm block rather than
2609 individual blocks as before.
2610 + GCC LPC2000 code now explicitly uses R0 rather than letting the assembler
2611 choose the register to use as a temporary register during the context
2613 + Added portNOP() macro.
2614 + The compare match load value on LPC2000 ports now has 1 added to correct
2616 + The minimal stack depth has been increased slightly on the WIZC PIC18
2619 Changes between V3.2.3 and V3.2.4
2621 + Modified the GCC ARM7 port layer to allow use with GCC V4.0.0 and above.
2622 Many thanks to Glen Biagioni for the provided update.
2623 + Added a new Microblaze port and demo application.
2624 + Modified the SAM7X EMAC demo to default to use the MII interface rather
2625 than the RMII interface.
2626 + Modified the startup sequence of the SAM7X demo slightly to allow the
2627 EMAC longer to auto negotiate.
2629 Changes between V3.2.2 and V3.2.3
2631 + Added MII interface support to the SAM7X EMAC peripheral driver.
2632 Previously versions worked with the RMII interface only.
2633 + Added command line GCC support to the SAM7X lwIP demo. Previously the
2634 project could only be built using the CrossWorks IDE. Modifications to
2635 this end include the addition of a standard makefile and linker script to
2636 the download, and some adjustments to the stacks allocated to each task.
2637 + Changed the page returned by the lwIP WEB server demo to display the
2638 task status table rather than the TCP/IP statistics.
2639 + Corrected the capitalisation of some header file includes and makefile
2640 dependencies to facilitate use on Linux host computers.
2641 + The various LPC2000 ports had a mistake in the timer setup where the
2642 prescale value was written to T0_PC instead of T0_PR. This would have
2643 no effect unless a prescale value was actually required. This has been
2646 Changes between V3.2.1 and V3.2.2 - Released 23 September, 2005
2648 + Added an IAR port for the Philips LPC2129
2649 + The Atmel ARM7 IAR demo project files are now saved in the IAR Embedded
2650 Workbench V4.30a format.
2651 + Updated the J-Link macro file included with the SAM7X uIP demo project
2652 to allow the demo board to be reset over the J-Link.
2654 Changes between V3.2.0 and V3.2.1 - Released 1 September, 2005
2656 + Added lwIP demo for AT91SAM7X using Rowley tools.
2657 + Added uIP demo for AT91SAM7X using IAR tools.
2658 + Added function xTaskGetCurrentTaskHandle().
2659 + Renamed events.h to mevents.h to prevent it conflicting with the events.h
2660 generated automatically by the HCS12 processor expert utility. events.h
2661 is only used by the PC demo application.
2662 + Both PIC18 ports now initialise the TBLPTRU to 0 as this is the value
2663 expected by the compiler, and the compilers do not write to this
2665 + The HCS12 banked model demo now creates the 'suicide' tasks immediately
2666 prior to starting the scheduler. These tasks should be the last tasks to
2667 get started in order for the test to function correctly.
2669 Changes between V3.1.1 and V3.2.0 - Released 29 June, 2005
2671 V3.2.0 introduces two new MSP430 ports and corrects a minor kernel
2672 issues. Thanks to Ares.qi for his input.
2674 + Added two MSP430 ports that use the Rowley CrossWorks development tools.
2675 One port just mirrors the existing GCC port. The other port was provided
2676 by Milos Prokic. Thanks!
2677 + V3.2.0 corrects the behavior when vTaskPrioritySet() or vTaskResume()
2678 are called while the scheduler is locked (by a call to
2679 vTaskSuspendAll()). When this is done the subject task now starts to
2680 execute immediately when the scheduler is unlocked if it has the highest
2681 priority that is ready to run. Previously there was a possibility that
2682 the task would not run until the next RTOS tick or call to portYIELD().
2683 + Another similar small correction ensures that in the case where more than
2684 one task is blocked on a semaphore or queue, the task with the highest
2685 priority is guaranteed to be unblocked first.
2686 + Added a couple of more test tasks to the PC demo which cover the points
2689 Changes between V3.1.0 and V3.1.1 - Released 21st June, 2005
2691 This release updates the HCS12 port. The common kernel code
2694 + Updated the HCS12 port to support banking and introduced a demo
2695 application for the MC9S12DP256. The new demo application is
2696 located in the Demo/HCS12_CodeWarrior_banked directory.
2697 + The name of the directory containing the MC9S12F32 demo application
2698 has been changed to Demo/HCS12_CodeWarrior_small (as in 'small'
2700 + MC9S12F32 demo updated slightly to use the PLL. The CPU speed for the
2701 demo application is now 24MHz. Previously it was 8MHz.
2702 + The demo application file Demo/Common/Minimal/death.c has a slight
2703 alteration to prevent it using floating point variables.
2706 Changes between V3.0.0 and V3.1.0 - Released 11th June, 2005
2708 + Added new ports for ST Microsystems STR71x, and Freescale HCS12
2709 microcontrollers. Currently the HCS12 port is limited to the small
2710 memory model. Large memory models will be supported in the next
2712 + PIC18 wizC port updated. Thanks to Marcel van Lieshout for his
2713 continuing contribution.
2714 + The accuracy of the AVR port timer setup has been improved. Thanks to
2715 Thomas Krutmann for this contribution.
2716 + Added a new conditional compilation macro configIDLE_SHOULD_YIELD.
2717 See the WEB documentation for details.
2718 + Updated the CrossWorks uIP demo to build with V1.4 of CrossWorks.
2719 + Slight modification to the SAM7 release build configuration to correct
2720 an include path definition.
2721 + Updated the MPLAB PIC18 documentation to provide extra details on linker
2724 Changes between V3.0.0 and V2.6.1 - Released 23rd April, 2005
2726 V3.0.0 includes many enhancements, so this history list is broken into
2727 subsections as follows:
2731 Directory name changes
2732 Kernel and miscellaneous changes changes
2736 + Each port now defines BaseType_t as the data type that is most
2737 efficient for that architecture. The type BaseType_t is used
2738 extensively in API calls necessitating the following changes to the
2739 FreeRTOS API function prototypes.
2741 See the "New for V3.0.0" section of the FreeRTOS online
2742 documentation for full details of API changes.
2746 + The AT91FR40008 ARM7 port contributed by John Feller is now included
2747 in the download (thanks John!).
2748 + The PIC18 port for the wizC/fedC compiler contributed by Marcel van
2749 Lieshout is now included in the download (thanks Marcel!).
2750 + The IAR port for the AVR microcontroller has been upgraded to V3.0.0
2751 and is now a supported port.
2753 - Directory name changes
2755 For consistency, and to allow integration of the new ports, the
2756 following directory names have been changed.
2758 + The source/portable/GCC/ARM7 directory has been renamed
2759 source/portable/GCC/ARM7_LPC2000 so it is compatible with the naming
2760 of other GCC ARM7 ports.
2761 + The Demo/PIC directory has been renamed Demo/PIC18_MPLAB to
2762 accommodate the wizC/fedC PIC port.
2763 + The demo applications for the two AVR ports no longer share the same
2764 directory. The WinAVR demo is in the Demo/AVR_ATMega323_WinAVR
2765 directory and the IAR port in the Demo/AVR_ATMega323_IAR directory.
2768 - Kernel and miscellaneous changes changes
2770 See the "New for V3.0.0" section of the FreeRTOS online
2771 documentation for more information.
2773 + Previously 'portmacro.h' contained some user editable definitions
2774 relating to the user application, and some fixed definitions relating
2775 specifically to the port being used. The application specific
2776 definitions have been removed from 'portmacro.h' and placed inside a
2777 new header file called 'FreeRTOSConfig.h'. 'portmacro.h' should now
2778 never be modified by the user. A 'FreeRTOSConfig.h' is now included
2779 in each of FreeRTOS/Demo subdirectories - as it's settings relate to
2780 the demo application rather than being specific to the port.
2781 + Introduced configUSE_IDLE_HOOK in idle task.
2782 + The idle task will yield when another idle priority task is ready to
2783 run. Previously the idle task would run to the end of its time slice
2785 + The idle task is now created when the scheduler is started. This
2786 requires less stack than the previous scheme where it was created upon
2787 creation of the first application task.
2788 + The function usPortCheckFreeStackSpace() has been renamed
2789 usTaskCheckFreeStackSpace() and moved from the portable layer to
2791 + Corrected spelling of portMINMAL_STACK_SIZE to portMINIMAL_STACK_SIZE.
2792 + The portheap.c file included with the AVR port has been deleted. The
2793 AVR demo now uses the standard heap1 sample memory allocator.
2794 + The GCC AVR port is now build using the standard make utility. The
2795 batch files used previously have been deleted. This means a recent
2796 version of WinAVR is required in order to create a binary suitable for
2797 source level debugging.
2798 + vTaskStartScheduler() no longer takes the configUSE_PREEMPTION
2799 constant as a parameter. Instead the constant is used directly within
2800 tasks.c and no parameter is required.
2801 + The header file 'FreeRTOS.h' has been created and is used to include
2802 'projdefs.h', 'FreeRTOSConfig.h' and 'portable.h' in the necessary
2803 order. FreeRTOS.h can now be included in place of these other
2805 + The header file 'errors.h' has been deleted. The definitions it
2806 contained are now located within 'projdefs.h'.
2807 + pvPortMalloc() now takes a size_t parameter as per the ANSI malloc().
2808 Previously an unsigned short was used.
2809 + When resuming the scheduler a yield is performed if either a tick has
2810 been missed, or a task is moved from the pending ready list into a
2811 ready list. Previously a yield was not performed on this second
2813 + In heap1.c an overflow check has been added to ensure the next free
2814 byte variable does not wrap around.
2815 + Introduced the portTASK_FUNCTION() and portTASK_FUNCTION_PROTO()
2817 + The MPLAB PIC port now saved the TABLAT register in interrupt service
2820 Changes between V2.6.0 and V2.6.1 - Released Feb 22, 2005
2822 This version adds support for the H8 processor.
2826 + tskMAX_TASK_NAME_LEN removed from the task.h header and added to each
2827 individual portmacro.h file as portMAX_TASK_NAME_LEN. This allows RAM
2828 limited ports to allocate fewer characters to the task name.
2829 + AVR port - Replaced the inb() and outb() functions with direct memory
2830 access. This allows the port to be built with the 20050414 build of
2832 + GCC LPC2106 port - removed the 'static' from the definition of
2833 vNonPreemptiveTick() to allow the demo to link when using the cooperative
2835 + GCC LPC2106 port - Corrected the optimisation options in the batch files
2836 ROM_THUMB.bat, RAM_THUMB.bat, ROM_ARM.bat and RAM_ARM.bat. The lower case
2837 -o is replaced by an uppercase -O.
2838 + Tasks.c - The strcpy call has been removed when copying across the task
2840 + Updated the trace visualisation to always be 4 byte aligned so it can be
2841 used on ARM architectures.
2842 + There are now two tracecon executables (that convert the trace file binary
2843 into an ASCII file). One for big endian targets and one for little endian
2845 + Added ucTasksDeleted variable to prevent vTaskSuspendAll() being called
2846 too often in the idle task.
2847 + SAM7 USB driver - Replaced the duplicated RX_DATA_BK0 in the interrupt
2848 mask with the RX_DATA_BK1.
2851 Changes between V2.5.5 and V2.6.0 - Released January 16, 2005
2853 + Added the API function vTaskDelayUntil(). The demo app file
2854 Demo/Common/Minimal/flash.c has been updated to demonstrate its use.
2855 + Added INCLUDE_vTaskDelay conditional compilation.
2856 + Changed the name of the Demo/ARM7_AtmelSAM7S64_IAR directory to
2857 Demo/ARM7_AT91SAM7S64_IAR for consistency.
2858 + Modified the AT91SAM7S USB driver to allow descriptors that have
2859 a length that is an exact multiple of the FIFO to be transmitted.
2861 Changes between V2.5.4 and V2.5.5 - Released January 3, 2005
2863 This version adds support for the Atmel SAM7 ARM7 microcontrollers
2864 along with the IAR development tools.
2868 + Renamed the Demo/ARM7 directory to Demo/ARM7_LPC2106_GCC.
2869 + Renamed the Demo/ARM7_Keil directory to Demo/ARM7_LPC2129_Keil.
2870 + Modified the Philips ARM7 serial interrupt service routines to only
2871 process one interrupt per call. This seems to enable the ISR to
2872 operate more quickly.
2873 + Removed the 'far' keyword from the Open Watcom portable layer source
2874 files. This allows their use with V1.3 of Open Watcom.
2875 + Minor modifications to the SDCC build files to allow their use under
2876 Linux. Thanks to Frieder Ferlemann for this contribution.
2877 + Small change to sTaskCreate() to allow a context switch even when
2878 pxCreatedTask is NULL. Thanks to Kamil for this contribution.
2879 + inline keyword removed from vTaskSwitchContext() and VTaskIncrementTick()
2882 Changes between V2.5.3 and V2.5.4 - Released Dec 1, 2004
2884 This is an important maintenance release.
2886 The function cTaskResumeAll() has been modified so it can be used safely
2887 prior to the kernel being initialised. This was an issue as
2888 cTaskResumeAll() is called from pvPortMalloc(). Thanks to Daniel Braun
2889 for highlighting this issue.
2891 Changes between V2.5.2 and V2.5.3 - Released Nov 2, 2004
2893 The critical section handling functions have been changed for the GCC ARM7
2894 port. Some optimisation levels use the stack differently to others. This
2895 means the interrupt flags cannot always be stored on the stack and are
2896 instead now stored in a variable, which is then saved as part of the
2897 tasks context. This allows the GCC ARM7 port to be used at all
2898 optimisation levels - including -Os.
2900 Other minor changes:
2902 + MSP430 definition of usCriticalNesting now uses the volatile qualifier.
2903 This is probably not required but added just in case.
2905 Changes between V2.5.1 and V2.5.2 - Released Oct 26, 2004
2907 + Added the Keil ARM7 port.
2908 + Slight modification to comtest.c to make the delay periods more random.
2909 This creates a better test condition.
2911 Changes between V2.5.0 and V2.5.1 - Released Oct 9, 2004
2913 + Added the MSP430 port.
2914 + Extra comments added to the GCC ARM7 port.c and portISR.c files.
2915 + The memory pool allocated within heap_1.c has been placed within a
2916 structure to ensure correct memory alignment on 32bit systems.
2917 + Within the GCC ARM7 serial drivers an extra check is made to ensure
2918 the post to the queue was successful if then attempting immediately
2919 retrieve the posted character.
2920 + Changed the name of the constant portTICKS_PER_MS to portTICK_PERIOD_MS
2921 as the old name was misleading.
2924 Changes between V2.4.2 and V2.5.0 - Released Aug 12, 2004
2926 The RTOS source code download now includes three separate memory allocation
2927 schemes - so you can choose the most appropriate for your application.
2928 These are found in the Source/Portable/MemMang directory. The demo
2929 application projects have also been updated to demonstrate the new schemes.
2930 See the "Memory Management" page of the API documentation for more details.
2932 + Added heap_1.c, heap_2.c and heap_3.c in the Source/Portable/MemMang
2934 + Replaced the portheap.c files for each demo application with one of the
2935 new memory allocation files.
2936 + Updated the portmacro.h file for each demo application to include the
2937 constants required for the new memory allocators: portTOTAL_HEAP_SIZE and
2939 + Added a new test to the ARM7 demo application that tests the operation
2940 of the heap_2 memory allocator.
2943 Changes between V2.4.1 and V2.4.2 - Released July 14, 2004
2945 + The ARM7 port now supports THUMB mode.
2946 + Modification to the ARM7 demo application serial port driver.
2948 Changes between V2.4.0 and V2.4.1 - Released July 2, 2004
2950 + Rationalised the ARM7 port version of portEXIT_CRITICAL() -
2951 improvements provided by Bill Knight.
2952 + Made demo serial driver more complete and robust.
2955 Changes between V2.4.0 and V2.3.1 - Released June 30, 2004
2957 + Added the first ARM7 port - thanks to Bill Knight for the assistance
2959 + Added extra files to the Demo/Common/Minimal directory. These are
2960 equivalent to their Demo/Common/Full counterparts but with the
2961 calls to the functions defined in print.c removed.
2962 + Added TABLAT to the list of registers saved as part of a PIC18 context.
2964 Changes between V2.3.0 and V2.3.1 - Released June 25, 2004
2966 + Changed the way the vector table is defined to be more portable.
2967 + Corrected the definitions of SPH and SPL in portmacro.s90.
2968 The previous definitions prevented V2.3.0 operating if the iom323.h
2969 header file was included in portmacro.s90.
2971 Changes between V2.2.0 and V2.3.0 - Released June 19, 2004
2973 + Added an AVR port that uses the IAR compiler.
2974 + Explicit use of 'signed' qualifier on plain char types.
2975 + Modified the Open Watcom project files to use 'signed' as the
2977 + Changed odd calculation of initial pxTopOfStack value when
2978 portSTACK_GROWTH < 0.
2979 + Added inline qualifier to context switch functions within task.c.
2980 Ports that do not support the (non ANSI) inline keyword have the
2981 inline #define'd away in their respective portmacro.h files.
2983 Changes between V2.1.1 and V2.2.0 - Released May 18, 2004
2985 + Added Cygnal 8051 port.
2986 + PCLATU and PCLATH are now saved as part of the PIC18 context. This
2987 allows function pointers to be used within tasks. Thanks to Javier
2988 Espeche for the enhancement.
2989 + Minor changes to demo application files to reduce stack usage.
2990 + Minor changes to prevent compiler warnings when compiling the new port.
2992 Changes between V2.1.0 and V2.1.1 - Released March 12, 2004
2994 + Bug fix - pxCurrentTCB is now initialised before the call to
2995 prvInitialiseTaskLists(). Previously pxCurrentTCB could be accessed
2996 while null during the initialisation sequence. Thanks to Giuseppe
2997 Franco for the correction.
2999 Changes between V2.0.0 and V2.1.0 - Released Feb 29, 2004
3001 V2.1.0 has significant reworks that greatly reduce the amount of time
3002 the kernel has interrupts disabled. The first section of modifications
3003 listed here must be taken into account by users. The second section
3004 are related to the kernel implementation and as such are transparent.
3008 + The typedef TickType_t has been introduced. All delay times should
3009 now use a variable of type TickType_t in place of the unsigned long's
3010 used previously. API function prototypes have been updated
3012 + The configuration macro USE_16_BIT_TICKS has been introduced. If set
3013 to 1 TickType_t is defined as an unsigned short. If set to 0
3014 TickType_t is defined as an unsigned long. See the configuration
3015 section of the API documentation for more details.
3016 + The configuration macro INCLUDE_vTaskSuspendAll is now obsolete.
3017 + vTaskResumeAll() has been renamed cTaskResumeAll() as it now returns a
3018 value (see the API documentation).
3019 + ulTaskGetTickCount() has been renamed xTaskGetTickCount() as the type
3020 it returns now depends on the USE_16_BIT_TICKS definition.
3021 + cQueueReceive() must now >never< be used from within an ISR. Use the new
3022 cQueueReceiveFromISR() function instead.
3026 + A mechanism has been introduced that allows a queue to be accessed by
3027 a task and ISR simultaneously.
3028 + A "pending ready" queue has been introduced that enables interrupts to
3029 be processed when the scheduler is suspended.
3030 + The list implementation has been improved to provide faster item
3032 + The scheduler now makes use of the scheduler suspend mechanism in places
3033 where previously interrupts were disabled.
3035 Changes between V1.2.6 and V2.0.0 - Released Jan 31, 2004
3037 + Introduced new API functions:
3044 + Added conditional compilation options that allow the components of the
3045 kernel that are unused by an application to be excluded from the build.
3046 See the Configuration section on the WEB site for more information (on
3047 the API pages). The macros have been added to each portmacro.h file (
3048 sometimes called prtmacro.h).
3049 + Rearranged tasks.c.
3050 + Added demo application file dynamic.c.
3051 + Updated the PC demo application to make use of dynamic.c.
3052 + Updated the documentation contained in the kernel header files.
3053 + Creating a task now causes a context switch if the task being created
3054 has a higher priority than the calling task - assuming the kernel is
3056 + vTaskDelete() now only causes a context switch if the calling task is
3057 the task being deleted.
3059 Changes between V1.2.5 and V1.2.6 - Released December 31, 2003
3061 Barring the change to the interrupt vector (PIC port) these are minor
3064 + The interrupt vector used for the PIC master ISR has been changed from
3065 0x18 to 0x08 - where it should have always been. The incorrect address
3066 still works but probably executes a number of NOP's before getting to the
3068 + Changed the baud rate used by the AVR demo application to 38400. This
3069 has an error percentage of less than one percent with an 8MHz clock.
3070 + Raised the priority of the Rx task in demo\full\comtest.c. This only
3071 affects the Flashlite and PC ports. This was done to prevent the Rx
3072 buffer becoming full.
3073 + Reverted the Flashlite COM port driver back so it does not use the DMA.
3074 The DMA appears to miss characters under stress. The Borland Flashlite
3075 port was also calculating a register value incorrectly resulting in the
3076 wrong DMA source address being used. The same code worked fine when
3077 compiling with Open Watcom. Other minor enhancements were made to the
3079 + Modified the PIC serial Rx ISR to check for and clear overrun errors.
3080 Overrun errors seem to prevent any further characters being received.
3081 + The PIC demo projects now have some optimisation switched on.
3084 Changes between V1.2.4 and V1.2.5
3086 Small fix made to the PIC specific port.c file described below.
3088 + Introduced portGLOBAL_INTERRUPT_FLAG definition to test the global
3089 interrupt flag setting. Using the two bits defined within
3090 portINITAL_INTERRUPT_STATE was causing the w register to get clobbered
3091 before the test was performed.
3093 Changes between V1.2.3 and V1.2.4
3095 V1.2.4 contains a release version of the PIC18 port.
3096 An optional exception has been included with the GPL. See the licensing
3097 section of www.FreeRTOS.org for details.
3099 + The function xPortInitMinimal() has been renamed to
3100 xSerialPortInitMinimal() and the function xPortInit() has been renamed
3101 to xSerialPortInit().
3102 + The function sSerialPutChar() has been renamed cSerialPutChar() and
3103 the function return type chaned to portCHAR.
3104 + The integer and flop tasks now include calls to tskYIELD(), allowing
3105 them to be used with the cooperative scheduler.
3106 + All the demo applications now use the integer and comtest tasks when the
3107 cooperative scheduler is being used. Previously they were only used with
3108 the preemptive scheduler.
3109 + Minor changes made to operation of minimal versions of comtest.c and
3111 + The ATMega port definition of portCPU_CLOSK_HZ definition changed to
3112 8MHz base 10, previously it base 16.
3116 Changes between V1.2.2a and V1.2.3
3118 The only change of any significance is to the license, which has changed
3119 from the Open Software License to the GNU GPL.
3121 The zip file also contains a pre-release version of the PIC18 port. This
3122 has not yet completed testing and as such does not constitute part of the
3123 V1.2.3 release. It is still however covered by the GNU GPL.
3125 There are minor source code changes to accommodate the PIC C compiler.
3126 These mainly involve more explicit casting.
3128 + sTaskCreate() has been modified slightly to make use of the
3129 portSTACK_GROWTH macro. This is required for the PIC port where the
3130 stack grows in the opposite direction to the other existing ports.
3131 + prvCheckTasksWaitingTermination() has been modified slightly to bring
3132 the decrementing of usCurrentNumberOfTasks within the critical section,
3133 where it should have been since the creation of an eight bit port.
3135 Changes between V1.2.2 and V1.2.2a
3137 The makefile and buildcoff.bat files included with the AVR demo application
3138 have been modified for use with the September 2003 build of WinAVR. No
3139 source files have changed.
3141 Changes between V1.2.1 and V1.2.2
3143 There are only minor changes here to allow the PC and Flashlite 186 ports
3144 to use the Borland V4.52 compiler, as supplied with the Flashlite 186
3147 + Introduced a BCC directory under source\portable. This contains all the
3148 files specific to the Borland compiler port.
3149 + Corrected the macro naming of portMS_PER_TICK to portTICKS_PER_MS.
3150 + Modified comtest.c to increase the rate at which the string is
3151 transmitted and received on the serial port. The Flashlite 186 demo
3152 app baud rate has also been increased.
3153 + The values of the constants used in both integer.c files have been
3154 increased to force the Borland compiler to use 32 bit values. The
3155 Borland optimiser placed the previous values in 16 bit registers, and in
3156 So doing invalidated the test.
3158 Changes between V1.2.0 and V1.2.1
3160 This version includes some minor changes to the list implementation aimed
3161 at improving the context switch time - with is now approximately 10% faster.
3162 Changes include the removal of some null pointer assignment checks. These
3163 were redundant where the scheduler uses the list functions, but means any
3164 user application choosing to use the same list functions must now check
3165 that no NULL pointers are passed as a parameter.
3167 The Flashlite 186 serial port driver has also been modified to use a DMA
3168 channel for transmissions. The serial driver is fully functional but still
3169 under development. Flashlite users may prefer to use V1.2.0 for now.
3173 + Changed the baud rate for the ATMega323 serial test from 19200 to 57600.
3174 + Use vSerialPutString() instead of single character puts in
3175 Demo\Full\Comtest.c. This allows the use of the flashlite DMA serial
3176 driver. Also the check variable only stops incrementing after two
3177 consecutive failures.
3178 + semtest.c creates four tasks, two of which operate at the idle priority.
3179 The tasks that operate at the idle priority now use a lower expected
3180 count than those running at a higher priority. This prevents the low
3181 priority tasks from signalling an error because they have not been
3182 scheduled enough time for each of them to count the shared variable to
3183 the higher original value.
3184 + The flashlite 186 serial driver now uses a DMA channel for transmissions.
3185 + Removed the volatile modifier from the list function parameters. This was
3186 only ever included to prevent compiler warnings. Now warnings are
3187 removed by casting parameters where the calls are made.
3188 + prvListGetOwnerOfNextEntry() and prvListGetOwnerOfHeadEntry() have been
3189 removed from list.c and added as macros in list.h.
3190 + usNumberOfItems has been added to the list structure. This removes the
3191 need for a pointer comparison when checking if a list is empty, and so
3193 + Removed the NULL check in vListRemove(). This makes the call faster but
3194 necessitates any application code utilising the list implementation to
3195 ensure NULL pointers are not passed.
3196 + Renamed portTICKS_PER_MS definition to portMS_PER_TICK (milli seconds
3197 per tick). This is what it always should have been.
3199 Changes between V1.01 and V1.2.0
3201 The majority of these changes were made to accommodate the 8bit AVR port.
3202 The scheduler workings have not changed, but some of the data types used
3203 have been made more friendly to an eight bit environment.
3207 + Changed the version numbering format.
3209 + Split the directory demo\common into demo\common\minimal and
3210 demo\common\full. The files in the full directory are for systems with
3211 a display (currently PC and Flashlite 186 demo's). The files in the
3212 minimal directory are for systems with limited RAM and no display
3213 (currently MegaAVR).
3214 + Minor changes to demo application function prototypes to make more use
3216 + Within the scheduler itself the following functions have slightly
3217 modified declarations to make use of 8bit data types where possible:
3221 usQueueMessageWaiting(),
3222 sQueueSendFromISR(),
3225 sSemaphoreGiveFromISR(),
3227 sTaskMoveFromEventList().
3229 Where the return type has changed the function name has also changed in
3230 accordance with the naming convention. For example
3231 usQueueMessageWaiting() has become ucQueueMessageWaiting().
3232 + The definition tskMAX_PRIORITIES has been moved from task.h to
3233 portmacro.h and renamed portMAX_PRIORITIES. This allows different
3234 ports to allocate a different maximum number of priorities.
3235 + By default the trace facility is off, previously USE_TRACE_FACILITY
3237 + comtest.c now uses a psuedo random delay between sends. This allows for
3238 better testing as the interrupts do not arrive at regular intervals.
3239 + Minor change to the Flashlite serial port driver. The driver is written
3240 to demonstrate the scheduler and is not written to be efficient.
3244 Changes between V1.00 and V1.01
3246 These changes improve the ports. The scheduler itself has not changed.
3248 Improved context switch mechanism used when performing a context
3249 switch from an ISR (both the tick ISR and the serial comms ISR's within
3250 the demo application). The new mechanism is faster and uses less stack.
3252 The assembler file portasm.asm has been replaced by a header file
3253 portasm.h. This includes a few assembler macro definitions.
3255 All saving and restoring of registers onto/off of the stack is now handled
3256 by the compiler. This means the initial stack setup for a task has to
3257 mimic the stack used by the compiler, which is different for debug and
3260 Slightly changed the operation of the demo application, details below.
3264 + portSWITCH_CONTEXT() replaced by vPortFirstContext().
3265 + pxPortInitialiseStack() modified to replicate the stack used by the
3267 + portasm.asm file removed.
3268 + portasm.h introduced. This contains macro definitions for
3269 portSWITCH_CONTEXT() and portFIRST_CONTEXT().
3270 + Context switch from ISR now uses the compiler generated interrupt
3271 mechanism. This is done simply by calling portSWITCH_CONTEXT and leaving
3272 the save/restore to compiler generated code.
3273 + Calls to taskYIELD() during ISR's have been replaced by calling the
3274 simpler and faster portSWITCH_CONTEXT().
3275 + The Flashlite 186 port now uses 186 instruction set (used to use 80x86
3277 + The blocking queue tasks within the demo application did not operate
3278 quite as described. This has been corrected.
3279 + The priority of the comtest Rx task within the demo application has been
3280 lowered. Received characters are now processed (read from the queue) at
3281 the idle priority, allowing low priority tasks to run evenly at times of
3282 a high communications overhead.
3283 + Prevent the call to kbhit() in main.c for debug builds as the debugger
3284 seems to have problems stepping over the call. This if for the PC port
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