[U-Boot-Users] 7xx/74xx cache question
richard.danter at ntlworld.com
Fri Jul 15 16:03:23 CEST 2005
Further progress on my port. I can now write to flash!
I noticed in lib_ppc/board.c board_init_r() that on e500 CPU's the
unlock_ram_in_cache() function is called. The 7xx/74xx also locks the
init RAM in the dcache, but nowhere is it unlocked.
I tried calling unlock_ram_in_cache() from my board's misc_init_r()
function, but this crashes U-Boot.
As an experiment, I left the cache locked, but then ran the "dcache off"
command from the shell. If I do printenv before turning the dcache off
it is all OK, if I do it after then it crashes.
With my debugger I can see that the gd data structure is garbage when
env_get_char_memory() is called. But I thought all data was copied to
the main sys RAM.
Is there something else I need to do before/after calling
unlock_ram_in_cache() so I can use the D-Cache as normal?
PS Calling icache_enable() from misc_init_r() seems to work fine.
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