Memory model for RTOS and No RTOS was initially single stack and heap,
only few targets implemented 2-region RAM model.
2-region RAM model is applied for all toolchains and targets.
GCC: __wrap__sbrk was implemented for 2-region ram model, with switch to 2-region
for all targets, we do not need target specific implementation of this API
Also _sbrk is WEAK function, hence can be over written in target folder for
special cases
Earlier if interrupt stack is specified it was used and remaining section of
IRAM was used to allocate heap, if stack is not specified heap section was
reduced by isr stack size and it was added at the end of RAM
With 2-region RAM support interrupt stack will always be specified.
Refactor the Mbed 5 boot process to make is simpler and more modular.
This is done by breaking the boot sequence into 4 distinct steps -
Target setup, Toolchain setup, RTOS setup and Mbed setup. This patch
also move toolchain specific code into a per toolchain folder to make
it more maintainable.
deepikabhavnani
Przemyslaw Stekiel
Martin Kojtal
Russ Butler