Yes, I will use the SysTick for the real time clock source, moving this
to the architecture. So there will be no need to define this in new
variants and platforms. We probably should provide macros for overriding
though?!?
That is easy to do. The porting guide says the official interface is:
HAL_CLOCK_INITIALIZE( period )
HAL_CLOCK_RESET( vector, period )
HAL_CLOCK_READ( pvalue )
So you can include var_io.h or plf_io.h first and then do:
ifndef HAL_CLOCK_INITIALIZE( period )
#define HAL_CLOCK_INITIALIZE cyg_cortex_clock_init( (period))
#endif
etc...