CMSIS-RTOS (CMSIS-RTOS RTX) Example Program
#include "cmsis_os.h"
/* Renamed main() function */
void app_main (void const *argument) {
// contents of old "main"
}
osThreadDef(app_main, osPriorityNormal, 1, 0);
int main (void) {
// System Initialization
SystemCoreClockUpdate();
// ...
osKernelInitialize();
// initialize peripherals here
/* Create the API v1 thread */
osThreadCreate(osThread(app_main), NULL);
osKernelStart();
for (;;);
}
/*----------------------------------------------------------------------------
*---------------------------------------------------------------------------*/
#include "cmsis_os2.h"
void app_main (void *argument) {
// ...
for (;;) {}
}
int main (void) {
// System Initialization
SystemCoreClockUpdate();
// ...
osKernelInitialize(); // Initialize CMSIS-RTOS
// initialize peripherals here
/* Create the API v2 thread */
osThreadNew(app_main, NULL, NULL); // Create thread with default settings
osKernelStart(); // Start thread execution
for (;;) {}
}
CMSIS-RTOS (CMSIS-RTOS RTX) is based on the RTX kernel and is part of the CMSIS software pack...
Migrate RTX to CMSIS-RTOSv1
- Replace RTX_Conf.c with RTX_Conf_CM.c.
General Differences Between RTX and CMSIS-RTOS RTX
|
|
RTX |
CMSIS-RTOS RTX |
|
Time slice |
RTX is using kernel ticks as the standard unit for measuring periods |
CMSIS-RTOS fully relies on milliseconds as this provides a fully qualified timing base without knowing the configuration of a tick |
|
Response time |
-no change- |
|
|
Memory requirements |
Code < 4KBytes / User Timer: 8 Bytes |
Code < 5KBytes / User Timer: 20 Bytes |
|
Terminology |
Tasks / Events |
Threads / Signals |
|
Delivery |
Integrated in MDK4 releases |
Part of CMSIS software pack |
|
System Tasks |
Init task created by user |
Main runs as first system task / 1 dedicated task for user timers |
|
Priorities |
Up to 250 numerical task priorities |
Up to 7 named thread priorities |
Migrate CMSIS-RTOSv1 to CMSIS-RTOSv2
RTX5 supplies both API layers: CMSIS-RTOS v1 & CMSIS-RTOS v2...
CMSIS-RTOS v2 provides multiple API interfaces:
- CMSIS-RTOS2 is the new C function API that supports dynamic object
- CMSIS-RTOS C API v1 is a C function API that is backward compatible with CMSIS-RTOS v1.
- CMSIS-RTOS C++ API is a C++ class function API
All CMSIS-RTOS C API v1 functions that are implemented in the cmsis_os.h header file.
All CMSIS-RTOS C API v2 functions that are implemented in the cmsis_os2.h header file.
Include "cmsis_os2.h" in all modules where access to API v2 functions is required.
#include "cmsis_os.h" // ARM::CMSIS:RTOS:Keil RTX5
#include "cmsis_os2.h" // ARM::CMSIS:RTOS2:Keil RTX5
