The rtx SVC_Handler for IAR clobbers r0-r3 despite the number of
arguments. However, in the SVC calls, the __swi function is declared
with fewer arguments. IAR doesn't understand that the other registers are
clobbered and stores variables in r0-r3 when multiple SVCs are
dispatched in a single function.
This bug was noticed in osThreadExit, which hard-faults on IAR,
preventing any threads from exiting.
Prevent a switch to a NULL target thread by setting the new task to run
to be the idle task. Otherwise, we get nasty usage fault because we
would be returning from the rt_sys_init SVC with a PSP of 0x20.
Wrap software_init_hook so that it can be used or extended from outside the
RTOS. This is desirable so that code can be added to the software_init_hook
without making the RTOS depend on new features or libraries.
Add the OsEventObserver mechanism. A client interested in receiving
notifications on certain OS events can register to receive notifications
with osRegisterForOsEvents. This is useful for clients like the secure
memory allocator, which observes thread switching events in order to swap
in and out different memory allocator objects.
softdevice.
The call stack of the soft device can be 0x600 (1536) bytes long, by
adjusting the stack to a value of 2048 bytes, their is enough room for
the softdevice and RTX kernel to live together in the main stack.
Random issues due to stack overflow were visible with the previous value.
The NRF51 doesn't have a systick. When the MCU doesn't have a systick, the
HAL has to export several functions which will be use by the kernel to
manage the tick:
* os_tick_init provides the initialization function for the alternative
hardware timer.
* os_tick_val returns the current value of the alternative hardware timer.
* os_tick_ovf returns the overflow flag of the alternative hardware timer.
* os_tick_irqack is an interrupt acknowledge function that is called to
confirm the alternative hardware timer interrupt.
The HAL should also call OS_Tick_Handler needs to be called as the
hardware timer interrupt function.
In the case of the NRF51, two RTCs are available:
* RTC0: reserved for soft device
* RTC1: used by us_ticker.
RTC1 is a 4 channels timers, channel 0 is used for us_ticker, and
in this port channel 1 is used for tick generation.
Implementation notes:
* RTC1_IRQHandler: has to be written in assembly otherwise a stack
overflow will occur because the function OS_Tick_Handler never
returns. This function is called when RTC1 channel IRQ is triggered.
* tick generation has been optimised for a tick with a duration of
1000us.
* us_ticker can still be compiled and used without RTX enabled.
More information about alternative timer as RTX Kernel Timer:
https://www.keil.com/pack/doc/CMSIS/RTX/html/_timer_tick.html
Add lock functions so that malloc and environment variable access are
thread safe. Add the compiler option "-o thread-safe" to use the full
version of newlib which is thread safe.
Note that this patch does NOT make file access thread safe.
Add the locks and flags necessary to make the IAR standard library
thread safe. These changes consist of:
-Add compiler flag "--guard_calls" to ensure C++ function-static
variables with dynamic initializers are initialized in a
thread safe manner
-Add the linker flag "--threaded_lib" so the thread safe version of
the standard library is used
-Implement mutex functions required for IAR thread safety
-Create a set of stub functions in retarget.c for when the rtos is not present
Added an #ifndef directive to the __MBED_CMSIS_RTOS_CM and __CMSIS_RTOS macro definitions in order to prevent "Incompatible redefinition of macro" warnings from the online compiler.
- Allows threads to started separately from when they are declared,
avoiding the need to dynamically allocate threads at runtime.
- Allows multiple threads to join without forceful termination. Allowing
threads to synchronize on cleanup.
Christopher Haster
Sam Grove
Jaeden Amero
Niklas Hauser
Vincent Coubard
0xc0170
Steven Cooreman
Russ Butler
Neil Thiessen
Russ Butler
Mihail Stoyanov