|
|
Now instead of init() and main() being responsible for all
initialization, individual modules can link in their own
initialization routines.
There are 7 levels for these initializiation routines.
So far these are how the levels are defined
level 0 - Here the world is dark. Nothing is initialized.
This level is responsible for initializing the
system clock.
level 1 - The system clock has been configured, but nothing else. Not
even global variables. This level is responsible for loading
the data sections from flash and clearing the .bss section.
level 2 - USART2 is enabled and set to be the main kernel logging
vehicle. From this point on klogf(...) can be used.
level 3 - The NVIC is reset to point to the flash. From this point
on interrupts can be received. I expect this is where
most core initialization routines will take place
levels 4 to 7 - User initializiation levels.
main - main() is called after all 8 initialization levels have executed,
so in a sense main() is like a 9th initialization level, except
that there is can be only one main() routine whereas there can be
multiple initalization routines per level.
|
