Hi list,
I am trying to cleanly integrate a new coldfire MCF5445x-based board into U-Boot. The problem I have is: - the board is booted from serial flash, meaning that SDRAM setup has to be done in assembler from a small pre-loader - the existing code for this already has some #ifdefs for handling different evaluation boards - I would like to be able to switch between 2 or 3 board assembly options requiring different memory setup, possibly by reading GPIOs used as strap pins.
The existing code is in cpu/mcf5445x/start.S. My idea would be to make the actual SDRAM init (ll. 190-284) conditional: #if defined(BOARD_ASM_SDRAM_INIT) BOARD_ASM_SDRAM_INIT #else [ll.190-284] #endif
BOARD_SDRAM_INIT could be #defined in our board configuration header.
Like this the global code would not be cluttered with #ifdefs, but some parts of course would be duplicated. I see no straight-forward way to set the part and board specific register values in a generic manner if the actual values shall also be depending on board-specific GPIO pins.
Is there any objection against such an implementation, or any other example how this could be done in a better way?
Regards, Wolfgang