[PATCH] arch/powerpc/lib/copy_32.S: Use alternate memcpy for MPC512x and MPC52xx
Segher Boessenkool
segher at kernel.crashing.org
Wed Jun 30 02:58:23 EST 2010
> These processors will corrupt data if accessing the local bus with
> unaligned
> addresses. This version fixes the typical case of copying from
> Flash on
> the
> local bus by keeping the source address always aligned.
On many platforms accessing ROM as RAM simply doesn't work(*). You
shouldn't
map ROM as if it is RAM, and shouldn't use the same access functions
on it.
Segher
(*) Example: any existing 970 system will checkstop as soon as you
try to
do any cacheable access to some ROM. Another example of course is
unaligned
accesses on pretty much any system, no matter whether it's called a
bug or
a feature on that system :-P
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