Re: [hatari-devel] Wrong bus error stack frame with 68000 and JSR

[Toni Wilen <twilen@xxxxxxxxxx>]

>> I.e., for branches, jumps and returns, the stacked PC is "near" the PC

>> of the branch/jump/return instruction, and not the target of this
>> instruction. Sadly, the exact offset is not documented, and probably
>> depends on instruction and addressing mode.
>
>Today, I did some more testing on a real 68000. The stacked PC has the
>following offset to the offending JSR:

I also started fixing this few hours ago, after fixing cputester and getting the bus error expansion hardware to work (bad connections and random crashes..) to handle these better. None of these tests were properly run previously..

Following 68000 jump/branch/return instructions now have correct bus error stack frame (all addressing modes, except JMP/JSR absolute short but it seems all of them work mostly identically):

JSR

BSR

JMP

DBcc

Bcc

RTE

RTR

RTS

Both jump to bus error address - 2 (second prefetch causes bus error) and jump to address that causes bus error (first prefetch causes bus error) cases tested and confirmed.

Fix is in winuae tree.