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Author Topic: Dreamcast ASM  (Read 2630 times)

Pokeytax

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Dreamcast ASM
« on: July 10, 2013, 09:21:13 pm »
I've only used highly functional debugging emulators, and trying to do some rudimentary Dreamcast ASM is killing me.  Demul has save states and NullDC has disassembly, but I can't even figure out how to do a memory dump.  Does anyone know the right tools to use?  Or are we just hoping Demul eventually gets there?

FAST6191

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Re: Dreamcast ASM
« Reply #1 on: July 11, 2013, 05:31:45 am »
Yeah if you are used to no$gba, fceux, vba-sdl-h and such like then moving to later consoles can be a pain. I have not really taken the DC to a high level but hopefully I will be able to point you somewhere for the time being. Several emulators will have GDB stubs/support, lua scripting and whatever else but I am not sure what goes here (lxdream has a measure of GDB support).

Most will usually flank them with with cheat making tools like emuhaste and artmoney, the former seems to have nullDC support (though it might need a tweak for newer versions) right out of the box and the latter seems to be a favourite among DC cheat makers. Both programs actually afford quite high level abilities when it comes to making cheats but proper breakpoints, stepping and whatever else you are used to with the high level stuff is not so doable. Memory dumps are easy enough though.

A lot of the rest of the time it amounts to messing around with something like IDA as well.

Basically anything that is not a NES, SNES, GBA, PC or possibly the DS you will have to wing it using a combination of all sorts of tools (read static disassembly and cheat making tools) if you want to do anything more exotic that make cheats.

Pokeytax

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Re: Dreamcast ASM
« Reply #2 on: August 25, 2013, 09:41:57 am »
This was actually really helpful, thank you FAST.  I've finished the initial ASM/decompression.  NullDC is not that bad once you get used to it (although lack of save states is painful).

Up until now I have been hex-editing the ISO directly, but I really need to actually work with the GD-ROM/GDI.  Does anyone know an easy way of doing this?  GD-ROM Explorer is a great utility but it only extracts files, it doesn't import them.  I'm used to CDMage which is supereasy.  I may have to write my own so documentation would be helpful too.

Project is Segagaga, for the curious.
« Last Edit: August 25, 2013, 10:04:39 am by Pokeytax »

FAST6191

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Re: Dreamcast ASM
« Reply #3 on: August 25, 2013, 12:20:50 pm »
You might get something from http://www.romhacking.net/forum/index.php/topic,16323.0.html (the short version is there is a tool called ISO LBA Fix Utility from DeXT that sorts the later tracks into normal ISO files, not sure how you would go backwards though).

Pokeytax

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Re: Dreamcast ASM
« Reply #4 on: August 26, 2013, 07:13:44 pm »
Yep, that did the trick.  I'll have to figure out how to reverse it but I can manage with a before and after, looks like just padding.  Thanks for being incredibly prompt and helpful as always.