I found that on Cortex M0 or on Cortex M3 GCC ports,
there is no api for portSAVE_CONTEXT or port RESTORE_CONTEXT.
I guess the task can handle context switching
without those api’s in arm architecture, but what about ISR?
Don’t I need to wrap my ISR functions with portSAVE_CONTEXT
if a context switch will occur inside my ISR function?
If so, how should I define my own portSAVE_CONTEXT
and portRESTORE_CONTEXT for cortex m series?