MathewWi / genplus-gx

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Final Fight CD coredump during stage 1 boss battle #232

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago
1. start final fight cd (j)
2. fight till the end of stage 1
3. during the fight with "Damnd", a few seconds after the character "poison" 
appeared, just before hitting "damnd", the game crashes with a wii core dump.  

I've tried it again and again, it always crashed during this boss fight

i use japanese bios v1.0 for model 1, with all default setting.
my final fight cd dump is a dump with audio tracks extracted as .wav file. The 
game track is a .bin

i don't know if my game iso is a good one. Taken from 
http://edgeemu.net/details-33511.htm
i haven't tried the european and american versions of the game. I prefer this 
one as it is uncensored and clother to the arcade.

do you need some more informations (photoshot of the coredump ?)

Original issue reported on code.google.com by tournier...@gmail.com on 4 Jul 2012 at 9:17

GoogleCodeExporter commented 9 years ago
photo of the core dump would be useful yes, it will help figuring where it 
crashes
also a savestate just before the bug occurence so i could try to reproduce it

Original comment by ekeeke31@gmail.com on 4 Jul 2012 at 9:21

GoogleCodeExporter commented 9 years ago
I think I figured this one (reproduced on the win32 port).

For the record, the main CPU is running code from the end of Word-RAM in 1M 
mode (PC = $21EF1E) and is executing a PC-relative instruction that somehow 
make it accidentally read out of Word-RAM area(above $21FFFF). This area is 
cell image area and can theoretically be accessed but the emulator did not 
expected this case and mapped PC-relative access there to NULL memory address 
instead, hence the coredump.

Original comment by ekeeke31@gmail.com on 4 Jul 2012 at 11:01

GoogleCodeExporter commented 9 years ago
Thanks for the explanation
you find the root cause quite fast !
I will take a picture of the core dump, save the game states before the crash 
and post it tonight.

Original comment by tournier...@gmail.com on 5 Jul 2012 at 7:45

GoogleCodeExporter commented 9 years ago
Not sure if it could be related, but the European version will stay at the 
"ROUND 1 CLEAR!" message instead of loading the next level. No core dump 
whatsoever, though.

Using 2.00 BIOS.

Original comment by superballena on 5 Jul 2012 at 7:03

GoogleCodeExporter commented 9 years ago
[deleted comment]
GoogleCodeExporter commented 9 years ago
Probably not related...

Damn, I knew I should never have started Mega CD emulation, issues pop up 
faster than I can handle them, this is hell...

Original comment by ekeeke31@gmail.com on 5 Jul 2012 at 7:06

GoogleCodeExporter commented 9 years ago
Don't sweat it, man. Reaching this level in just one month is pretty impressive.

Some games run flawlessly already, and fixing any others will just be a plus in 
future updates. We love your work and will help testing as much as we can. :)

Original comment by superballena on 5 Jul 2012 at 8:01

GoogleCodeExporter commented 9 years ago
There's no hurry fixing bugs... take your time. Your work is already much 
appreciated and it should eat a lot of your free time.

Concerning the freeze on the european version with no coredump, it is perhaps a 
bad iso. I had a previous japanese iso thats freeze the emulator before the 
title screen. The emulator was just frozen and the wii drive blue light wasn't 
blinking anymore. no coredump, just stuck there 'til i reset the wii by myself. 
It would be better to start a new bug report until it is confirmed, rather than 
mixing the 2 issues.

Original comment by tournier...@gmail.com on 5 Jul 2012 at 8:31

GoogleCodeExporter commented 9 years ago
I know yes, it's just that I hate knowing bugs are there and do nothing ;-)

For the record, the freeze when loading next level is because of missing audio 
tracks (or more exactly invalid CD TOC). The same occurs at game over screen if 
you don't press continue. Does the same in Kega if you load an iso without any 
audio tracks. 

I guess more games rely on accurate TOC or will freeze at some point...

Original comment by ekeeke31@gmail.com on 5 Jul 2012 at 9:30

GoogleCodeExporter commented 9 years ago
Here is a save state just before the coredump.

It took me a lot of retries before triggering the bug tonight... i even came 
accross the bug described by superball after defeating the 1st level boss 
without triggering the bug. I will open a new issue for this one as his 
european iso and my japanese iso seem to behave the same.

I had to reload this save state a few times before triggering the coredump

Original comment by tournier...@gmail.com on 5 Jul 2012 at 10:32

Attachments:

GoogleCodeExporter commented 9 years ago
and now the coredump 

Original comment by tournier...@gmail.com on 5 Jul 2012 at 10:40

Attachments:

GoogleCodeExporter commented 9 years ago

Original comment by ekeeke31@gmail.com on 5 Jul 2012 at 11:46

GoogleCodeExporter commented 9 years ago
Thanks, the dump confirms what i have seen in win32 port: the emulator crashes 
while executing a 68k instruction that uses a PC relative offset which points 
to normally unused memory. Taking care of this kind of access fixed it.

Original comment by ekeeke31@gmail.com on 6 Jul 2012 at 9:43

GoogleCodeExporter commented 9 years ago
fixed in r693

Original comment by ekeeke31@gmail.com on 15 Jul 2012 at 3:43