[coreboot] Could I replace memmove function?

Andrew Wu andrewwu.tw at gmail.com
Sat Aug 17 22:40:21 CEST 2013

DMP/Vortex86EX can't cache ROM area on the top of 4G memory, so
romstage area can't be cached. :(

I am thinking...should I just replace memmove function with REP MOVS
version, or use __PRE_RAM__ macro to choose which memmove version to
use? (Because in romstage REP MOVS runs much faster).

2013/8/16 Patrick Georgi <patrick at georgi-clan.de>:
> Am 2013-08-15 14:01, schrieb Andrew Wu:
>> is 256-byte aligned, otherwise it will failback to use slower MOV
>> loop. MOV loop is much slower then
>> REP MOVSL on Vortex86EX, because reading instructions from ROM is slow.
> Can't you cache the ROM area?
> Other than that: Optimizing the common code is better than a special case.
> memmove won't change much, so that's a stable interface, but you never know
> what will happen (and few people will be able to test their changes on
> Vortex86).
> Patrick
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