Hello
Would it make sense to include support for sleeping ("wfi"
instruction) in idle thread for the cortex m3 architecture? The
current code in hal_arch.h looks like:
#if 0 //ndef HAL_IDLE_THREAD_ACTION
#define HAL_IDLE_THREAD_ACTION(__count) __asm__ volatile ( "wfi\n" )
#else
#define HAL_IDLE_THREAD_ACTION(__count) CYG_EMPTY_STATEMENT
#endif
I guess this is not what it was meant to be. I would propose to add an option like CYGHWR_HAL_CORTEXM_IDLE_SLEEP to enable the wfi instruction:
#ifndef HAL_IDLE_THREAD_ACTION
# ifdef CYGHWR_HAL_CORTEXM_IDLE_SLEEP
# define HAL_IDLE_THREAD_ACTION(__count) __asm__ volatile ( "wfi\n" )
# else
# define HAL_IDLE_THREAD_ACTION(__count) CYG_EMPTY_STATEMENT
# endif
#endif
Also, currently var_arch.h gets not included in the hal_arch.h header, so it's impossible to override for example the HAL_IDLE_THREAD_ACTION macro. I guess this was just overlooked, or is it intentional?
I can provide a patch if there are no objections.