Hacking Possible EZ Omega Corruption Source

[kuwanger]

Previously I've stated that one can use old compilations of emulators with the EZ-Omega without issue. This, however, is sadly not the case. One of the last thing various Loopy/FluBBa based emulators do is writeconfig(); right before exit. This obviously has a non-negligible probability of changing the SRAM at a point where SRAM writes should be avoided. I noticed only after seeing the EZ Omega kernel source was patching the Goomba Color 2014-12-14 binary. I'm not certain if they also patched the PocketNES binary/source in the EZ Omega kernel.

Having said that, I've so far tracked down the related writeconfig() for a few of the emulator versions. In principle it'd be better to move writeconfig() to a better location, but that's a non-trivial amount of effort. For the moment, one can use my hexalter to patch out the final call in exit() to writeconfig() in the following emulators/compilations.

For Goomba Paletted v2.40:

hexalter goomba.gba 0x2656=0xc0,0x46,0xc0,0x46

For Goomba Color 3-31-08:

hexalter goombacolor.gba 0xf862=0xc0,0x46,0xc0,0x46

SMSAdvance v2.4:

hexalter smsadvance.gba 0x2352=0xc0,0x46,0xc0,0x46

PS - Always make sure you make backups. I haven't so far tested any of these. It's possible there are other relevant writeconfig() in the code in some emulators, although I'm fairly certain this is not the case. Also, I'm fairly certain that the EZ-Team went a little overboard and nopped one writeconfig() more than necessary (the one that occurs when the L+R menu appears).

Edit:

PSS - Built-in PocketNES and Goomba Color both have nops to avoid this.

 

[patters]

I saw this post and wondered whether this write to SRAM directly before exiting would be an issue for the EZ-Flash IV also. However it turns out not to be the case, as explained by Kuwanger in another post here:
https://gbatemp.net/threads/goomba-color-update-2019-05-04.537731/#post-8623975

The EZ-Flash Omega seems to monitor new SRAM writes and copy them to the SD card as soon as they happen, which is very different behaviour to the older products.