[U-Boot] Strange arm9 behaviour reading long(s) not aligned to 4 bytes boundary
Måns Rullgård
mans at mansr.com
Sat Jan 24 18:11:17 CET 2009
"dibacco at libero.it" <dibacco at libero.it> writes:
> Hi,
>
> I have something like this on a 32 bit little endian arm9 board (SAM9
> L9260):
>
> char buffer[] = { 0, 1, 2, 3, 4, 5, 6, 7 };
>
> long A = * ( (long*)
> buffer );
> long B = * ( (long*) (buffer + 2) );
>
> printf("A: %08x B: %08x", A,
> B);
>
> I would expect that A = 0x03020100 and B = 0x05040302
> instead I get the
> right value for A but B is 0x01000302 or something like this but anyway not
> what I expect.
> Is there something wrong on the board? It seems that only 4
> bytes aligned long are read correctly.
ARM9 does not support unaligned load/store. Yours is apparently
configured in the round-and-rotate mode.
--
Måns Rullgård
mans at mansr.com
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