Refactor cortexm_init to allow bits and pieces of
it to be called separately, while retaining the
current API, too. Needed for non-standard
Cortex-M initialisation, such as with nRF52
SoftDevice.
Instead of using `weak` function definitions, this PR handles
default implementations using `PROVIDES_x` defines, allowing
for cpus/pm realted modules to use their own implementations.
register is deprecated when building C++11 code and removed in C++17,
using it will cause build failures with C++ and -Werror. The register
hint keyword is likely ignored in GCC anyway.
- added a centralized core implementation for all cortex CPUs
- moved default stack size defines to cpu.h in cortexm_common
- moved uart0 bufsize define to cpu.h in cortexm_common
- moved typed of panic_t to cpu.h in cortexm_common
- removed coretx-m[0|3|4]
- moved their content to cortexm_common
- adjusted cortex Makefiles to this new name
- adjusted cortex Makefiles new structure
- fixes to cortexm-common
- Added ARM CMSIS headers to cortexm_common
- thread_exit fixes to cortexm-common
- cortexm-common adjusted documentation
- cortexm_common added eINT dINT defines for now
