Difference between revisions of "Fix Rexon crash"
From Sonic Retro
KingofHarts (talk | contribs) m (original guide by rhs) |
Scarred Sun (talk | contribs) m (Text replacement - "</asm>" to "</syntaxhighlight>") |
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Line 11: | Line 11: | ||
bmi.s loc_37462 | bmi.s loc_37462 | ||
bra.w JmpTo39_MarkObjGone | bra.w JmpTo39_MarkObjGone | ||
− | </ | + | </syntaxhighlight> |
That "branch to subroutine - loc_3750C" is what is causing the problem. It's happening too early. We need to move that command down a little bit. So change it to this: | That "branch to subroutine - loc_3750C" is what is causing the problem. It's happening too early. We need to move that command down a little bit. So change it to this: | ||
Line 21: | Line 21: | ||
bsr.w loc_3750C ; Now moved here to fix Rexon crash | bsr.w loc_3750C ; Now moved here to fix Rexon crash | ||
bra.w JmpTo39_MarkObjGone | bra.w JmpTo39_MarkObjGone | ||
− | </ | + | </syntaxhighlight> |
One more, go to "loc_37488:" and you should see this: | One more, go to "loc_37488:" and you should see this: | ||
Line 34: | Line 34: | ||
bsr.w JmpTo26_ObjectMove | bsr.w JmpTo26_ObjectMove | ||
bra.w JmpTo39_MarkObjGone | bra.w JmpTo39_MarkObjGone | ||
− | </ | + | </syntaxhighlight> |
Again, "branch to subroutine - loc_3750C" is too early. So change it to this: | Again, "branch to subroutine - loc_3750C" is too early. So change it to this: | ||
Line 47: | Line 47: | ||
bsr.w JmpTo26_ObjectMove | bsr.w JmpTo26_ObjectMove | ||
bra.w JmpTo39_MarkObjGone | bra.w JmpTo39_MarkObjGone | ||
− | </ | + | </syntaxhighlight> |
Done! The rexon crash will no longer happen. | Done! The rexon crash will no longer happen. |
Revision as of 21:29, 20 December 2015
(Original guide by redhotsonic)
On Hill Top Zone, it is possible to crash the game when hitting Rexon (the plesiosaur-like badnik that sits in the lava). Conflicts in the code cause it to jump to a section of code earlier than it was meant to jump to. This results in invalid opcodes being processed and an eventual crash.
Go to "loc_37454:" and you should see this:
<asm> loc_37454:
bsr.w loc_3750C subq.b #1,objoff_2A(a0) bmi.s loc_37462 bra.w JmpTo39_MarkObjGone
</syntaxhighlight>
That "branch to subroutine - loc_3750C" is what is causing the problem. It's happening too early. We need to move that command down a little bit. So change it to this:
<asm> loc_37454:
subq.b #1,objoff_2A(a0) bmi.s loc_37462 bsr.w loc_3750C ; Now moved here to fix Rexon crash bra.w JmpTo39_MarkObjGone
</syntaxhighlight>
One more, go to "loc_37488:" and you should see this:
<asm> loc_37488:
bsr.w loc_3750C moveq #$10,d0 add.w d0,x_vel(a0) subq.b #1,objoff_2A(a0) bmi.s loc_374A0 bsr.w JmpTo26_ObjectMove bra.w JmpTo39_MarkObjGone
</syntaxhighlight>
Again, "branch to subroutine - loc_3750C" is too early. So change it to this:
<asm> loc_37488:
moveq #$10,d0 add.w d0,x_vel(a0) subq.b #1,objoff_2A(a0) bmi.s loc_374A0 bsr.w loc_3750C ; Now moved here to fix Rexon crash bsr.w JmpTo26_ObjectMove bra.w JmpTo39_MarkObjGone
</syntaxhighlight>
Done! The rexon crash will no longer happen.