> Section 6.2.3 of the SA-1110 manual describes the procedure for
> software-flushing the dcache, as follows:
>
> mov r0, #0xe0000000
> add r1, r0, #8192
> 1: ldr r2, [r0], #32
> teq r1, r0
> bne 1b
>
> mcr p15, 0, r0, c7, c6, 0 @ invalidate D cache
> mov pc, lr
An interesting thing about this routine that is not precised
in the SA1110's manual is that the region 0xe0000000 needs to
be marked as cached (C=B=1). On second thought that sounds logical,
but it took me quite a bit of time to figure it out :-)
> I'm calling this from C, and as soon as I try to return from
> the calling
> routine, I get a data abort. Examination of the stack frame
> reveals that
> memory corruption has occurred.
Hypothesis: You entered the routine before turning the cache
on, then you think you flush the cache but you don't, the flush
routine returns fine because it's a stack-less return (forgive
my creation of words), then the caller tries to return with
a return value is suddenly cached and therefore not correct.
I know I'm not clear, it's friday evening..
Hope that helps anyway
Yves.
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