Hacking EZ Omega (with Pogoshell) Alpha

[kuwanger]

Well, for all multiboot plugins there'd have to be a jump instruction to EXWRAM and gba header written into PSRAM. For all .gba plugins, it'd be enough to swap "swi 0" for "swi 0x26".

If all your plugins can be renamed to .gba and you want to hack this yourself, you can hexedit 0x14bc02 and change it to 0x26. I believe that will cause hard reset for everything but multiboot plugins.

Note: I haven't actually tried this so can't really verify this. If that doesn't work though, it should be enough to nop out 0x14bc02 with 0xc0, 0x46 as the next function after is HardReset() which is normally called if you hold down L on normal roms. Again, I haven't tested this either.

 

[Sterophonick]

Would it also be feasible to just edit the reset.s file to produce the same effect?

 

[kuwanger]

Yea, if you want to edit reset.s and recompile it yourself. I personally don't really want a two second delay and probably won't add the feature.

 

[Sterophonick]

The bytes for the nop instruction in thumb are 0xc046?

 

[kuwanger]

Well, 0x46c0 but it's byte swapped which is why I wrote 0xc0, 0x46.

 

[Sterophonick]

Ok.

 

[Sterophonick]

If I do this, then all multiboot plugins will no longer work, right?

 

[kuwanger]

No, the code to run multiboot plugins is in Ezcard_OP.c. The plugin is copied/decompressed to EXWRAM and directly run from there.

 

[Sterophonick]

Ah, great.

 

[Sterophonick]

Didn't quite work with the emulators. Only worked with MSXAdvance and Cologne. Oh well.

 

[Sterophonick]

I'm having trouble with MSXAdvance, as it keeps rendering my collection of homebrew games unplayable. It is not the ROMs that I have, it is some other issue that I can't seem to figure out. No matter what, these games will never play, and will repeatedly reset the BIOS as soon as they boot up.

 

[kuwanger]

Does this happen only with the hard reset patch or with the normal soft reset as well? Btw, I was meaning to ask you what you meant with hard reset not quite working with the other emulators. Perhaps my suggestion doesn't work quite right at all?

 

[Sterophonick]

I am using the hard reset patch. I got it to work at one point, but then it stopped working straight after that.

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Cologne works just fine.

 

[Sterophonick]

Oddly enough, my abandonware games like Alibaba And The 40 Thieves and Jump Coaster work just fine with the reset patch.

 

[Sterophonick]

I just realized that the MSX games have to be 16k or lower to work properly.

 

[kuwanger]

Looking through the gamelist.txt, yea it looks like most the games listed are of the 8k/16k variety. Never really been into MSX (or C64 for that matter), so I wouldn't have a frame of reference of "working" except if black screened/rebooted.

 

[Sterophonick]

Looking through the gamelist.txt, yea it looks like most the games listed are of the 8k/16k variety. Never really been into MSX (or C64 for that matter), so I wouldn't have a frame of reference of "working" except if black screened/rebooted.

However, the games have worked previously. I trying a format of the sd card, and will see how well that goes.

 

[kuwanger]

Okay, after a little experimentation I don't think it'll actually work to hard reset for plugins. The issue is that I believe the BIOS hard reset function blanks external work ram. That's where the information is passed to a plugin on the name of the file, where it's located, and its size (among other things). For a lot of programs, there's a lot of flexibility and they'll actually try to search the address space for stuff so some stuff works (Goomba is one example, vgm player is another) and others don't (pce won't work and I don't think pocketnes will either). I presume that MSX Advance is guessing on the size/properties of the ROM it finds and that's why sometimes it works and sometimes it doesn't.

Now, if it does turn out that gbatek is wrong and the bios hard reset function actually takes parameters and I can disable the exwram blanking, I'd love to find out about it. But as it stands, you're out of luck.

 

[Sterophonick]

K, thanks.

 

[daddu3]

Yo, wondering if to try this out, but as you wrote to OP, this has potential to brick Omega?

I mainly wanna use this to implement Goomba-emulator so I can add borders to GB-games more easily - but are potential for corruption using a plugin of it high?