Hello Kitty Collection - Miracle Fashion Maker (Japan) black screen

[benderscruffy]

using 0.7.0
nothing but a black screen

[endrift]

Old bug, never looked into it too deeply.

[endrift]

Doesn't boot in any emulator. Does work on hardware though. This appears to have a similar root cause to #301 where it's reading a value from RAM and expecting it to be non-zero but it never sets it.

[endrift]

Looks like the RAM address (0x0200002C) gets initialized (to 0x02000140) right after the function that dies gets called. Confirmed that it gets to 0x080427AA on hardware, so it's not initialized properly on hardware yet I don't think, but for some reason it managed to break out of the loop on invalid RAM it gets into (it looks like it's trying to crawl a linked list, but the linked list is all invalid memory).

[endrift]

Fixed in 93633ea.

[michelhe]

Hey @endrift
I've read the blog post you made about this issue, thank you for the wonderful read! 👍
I myself toy with developing a GBA emulator in rust, and this game is booting successfully for me.
I suppose its due to that I'm not implementing the "open bus" behavior at all, I just return 0 for invalid memory region accesses, or mask out invalid address bits if the region is correct.
When I move on to implement open-bus, I will sure take into account the DMA lingering on the bus 😄

[endrift]

If you're wondering why Minish Cap hangs when you leave the house at the beginning of the game, that's because you don't have open bus emulated

[michelhe]

Sadly I did not get to experience that because I don't emulate EEPROM saves , but I will get there soon enough.