1 /*=======0=========1=========2=========3=========4=========5=========6=========7=========8=========9=========0=========1====*/
5 The <b>CMSIS-RTOS v2 (CMSIS-RTOS2)</b> provides generic RTOS interfaces for Arm® Cortex® processor-based
6 devices. It provides a standardized API for software components that require RTOS functionality and gives therefore serious
7 benefits to the users and the software industry:
8 - CMSIS-RTOS2 provides basic features that are required in many applications.
9 - The unified feature set of the CMSIS-RTOS2 reduces learning efforts and simplifies sharing of software components.
10 - Middleware components that use the CMSIS-RTOS2 are RTOS agnostic and are easier to adapt.
11 - Standard project templates of the CMSIS-RTOS2 may be shipped with freely available CMSIS-RTOS2 implementations.
13 \note The CMSIS-RTOS API Version 2 defines a minimum feature set. Implementations with extended features may be provided by
16 The CMSIS-RTOS2 manages the resources of the microcontroller system and implements the concept of parallel threads that run
19 Applications frequently require several concurrent activities. CMSIS-RTOS2 can manage multiple concurrent activities at the
20 time when they are needed. Each activity gets a separate thread which executes a specific task and this simplifies the
21 overall program structure. The CMSIS-RTOS2 system is scalable and additional threads can be added easily at a later time.
22 Threads have a priority allowing faster execution of time-critical parts of a user application.
24 The CMSIS-RTOS2 offers services needed in many real-time applications, for example, periodical activation of timer functions,
25 memory management, and message exchange between threads with time limits.
27 The CMSIS-RTOS2 addresses the following new requirements:
28 - Dynamic object creation no longer requires static memory, static memory buffers are now optional.
30 - Support for Armv8-M architecture that provides a secure and non-secure state of code execution.
32 - Provisions for message passing in multi-core systems.
33 - Full support of C++ run-time environments.
34 - C interface which is binary compatible across
35 <a href="http://infocenter.arm.com/help/topic/com.arm.doc.subset.swdev.abi/index.html">ABI compatible compilers</a>.
37 As a consequence of these requirements the CMSIS-RTOS2 has the following fundamental modifications:
38 - The functions osXxxxNew replace osXxxxCreate functions; osXxxxNew and osXxxxDelete create and destroy objects.
39 - The C function \c main is no longer started as a thread (this was an optional feature in CMSIS-RTOS v1).
40 - Functions that return osEvent have been replaced.
42 CMSIS-RTOS2 provides an translation layer to <a class="el" href="../../RTOS/html/index.html">CMSIS-RTOS v1</a>. It
43 is possible to intermix \ref rtos_api2 and <a class="el" href="../../RTOS/html/functionOverview.html">CMSIS-RTOS C API v1</a>
44 within the same application. Over time, you may migrate to the new API as explained in \ref os2Migration.
46 CMSIS-RTOS2 is not POSIX compliant, but has provisions to enable a C++11/C++14 interface.
48 The following sections provide further details about CMSIS-RTOS2 and the RTX reference implementation.
49 - \subpage rtos_revisionHistory documents changes made in each version for CMSIS-RTOS v2 and RTX v5.
50 - \subpage genRTOS2IF provides an overview about the APIs available with CMSIS-RTOS v2.
51 - \subpage functionOverview lists the CMSIS-RTOS2 API functions and the header file %cmsis_os2.h.
53 - \subpage rtosValidation describes the validation suite that is publicly available.
54 - \subpage os2Migration shows how to use CMSIS-RTOS2 in existing projects and lists function differences to CMSIS-RTOS v1.
56 - \subpage rtx5_impl provides general information about the operation and usage of RTX v5.
58 - \subpage rtx_safety provides comprehensive instructions for highly reliable applications.
64 CMSIS-RTOS2 in ARM::CMSIS Pack
65 ------------------------------
68 The following files relevant to CMSIS-RTOS2 are present in the <b>ARM::CMSIS</b> Pack directories:
70 :----------------------------|:-----------------------------------------------------------------------
71 \b CMSIS/Documentation/RTOS2 | This documentation
72 \b CMSIS/RTOS2/Include | \ref cmsis_os2_h
73 \b CMSIS/RTOS2/RTX | CMSIS-RTOS2 reference implementation based on RTX version 5
74 \b CMSIS/RTOS2/Source | Generic <b>OS tick</b> implementations for various processors based on \ref rtos_os_tick_api
75 \b CMSIS/RTOS2/Template | Compatibility layer to <a class="el" href="../../RTOS/html/index.html">CMSIS-RTOS v1</a>