| Re: [hatari-devel] 68000: Wrong order of bus accesses for move.l xx,-(Ay) |
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Toni Wilen schrieb:
> This should fix it. Also fixes exception stack frame fault address if
> MOVE.L ea,-(an) causes address error.
Thank you. I didn't try applying the patch to Hatari source code, so I
have to ask: Does it also fix MOVEM.L xx,-(An), which also writes in
descending order?
Also, this issue prompted me to go through the "YACHT" document, looking
for unusual access patterns. For example ADDX.L -(An),-(Ay) does the
*reads* in descending order. I have tested on a real 68000 that...
LEA $0,A0
LEA $1000,A1
ADDX.L -(A0),-(A1)
.... does in fact generate the bus error at $FFFFFFFE. In Hatari (and
thus in the UAE emulation) it will generate the bus error at $FFFFFFFC.
Same goes for SUBX.L. The writes are also in descending order, as I just
tested.
Regards
Christian
--
Christian Zietz - CHZ-Soft - czietz@xxxxxxx
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