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Great read! Do you have any resources on getting started with Dreamcast game reverse engineering? I've been wanting to do some things with Skies of Arcadia, an

Great read! Do you have any resources on getting started with Dreamcast game reverse engineering? I've been wanting to do some things with Skies of Arcadia, and I've been hoping there exist techniques more systematic than "see what values change between memory snapshots".

bbayles 2y ago
I've poked around a bit with that game! The main trick is to import the memory snapshot (various ways of dumping it to a file; people like Cheat Engine for this) into Ghidra. Ghidra can analyze the SuperH processor machine code natively, so the auto analysis will turn up lots of functions.
coldpie 2y ago
> I've been hoping there exist techniques more systematic than "see what values change between memory snapshots". FWIW this is pretty much the standard method for locating value locations in RAM. It actually works pretty well. Some emulators have tools built in for that, like Dolphin for example. Even old game hacking tools like the Gameshark for N64 used the technique, with an on-console UI. I don't know if any Dreamcast emulators have tools for it or not. I wrote about the technique in Dolphin here (and the followup article is also about console game hacking with Ghidra): https://www.smokingonabike.com/2021/01/17/hacking-super-monkey-ball-part-1-banana-bunch-values/ https://www.smokingonabike.com/2021/01/17/hacking-super-monk...
- AdmiralAsshat 2y ago
  > Some emulators have tools built in for that, like Dolphin for example. This was an advertised feature of some DS flashcarts back in the day, too. I can't remember if it was the R4, the DSTwo, or what...but I recall an example video for their "Make your own cheats!" feature, which involved playing something like Super Mario Bros, turning on the "Cheats Finder" feature, then grabbing a coin, and maybe doing it a few times. The manager would then figure out the value that's changing in memory (presumably the sector that stores your coin amount), create the "cheat", and then you would enable it and watch your coin value go up.
- jasomill 2y ago
  Incidentally, Skies of Arcadia Legends on Dolphin is fantastic: https://www.youtube.com/playlist?list=PLwH1xJhcXG0dBlmWL_DTuKyHILksdH8jn https://www.youtube.com/playlist?list=PLwH1xJhcXG0dBlmWL_DTu...
- djmips 2y ago
  And old skool 'trainer' tools on PC. Someone more familiar that myself could give better information but I remember trying them out in the early 2000s and remarking how they reminded me of GameShark for PC

bbayles 2y ago

I've poked around a bit with that game! The main trick is to import the memory snapshot (various ways of dumping it to a file; people like Cheat Engine for this) into Ghidra. Ghidra can analyze the SuperH processor machine code natively, so the auto analysis will turn up lots of functions.

coldpie 2y ago

> I've been hoping there exist techniques more systematic than "see what values change between memory snapshots". FWIW this is pretty much the standard method for locating value locations in RAM. It actually works pretty well. Some emulators have tools built in for that, like Dolphin for example. Even old game hacking tools like the Gameshark for N64 used the technique, with an on-console UI. I don't know if any Dreamcast emulators have tools for it or not. I wrote about the technique in Dolphin here (and the followup article is also about console game hacking with Ghidra): https://www.smokingonabike.com/2021/01/17/hacking-super-monkey-ball-part-1-banana-bunch-values/ https://www.smokingonabike.com/2021/01/17/hacking-super-monk...

AdmiralAsshat 2y ago
> Some emulators have tools built in for that, like Dolphin for example. This was an advertised feature of some DS flashcarts back in the day, too. I can't remember if it was the R4, the DSTwo, or what...but I recall an example video for their "Make your own cheats!" feature, which involved playing something like Super Mario Bros, turning on the "Cheats Finder" feature, then grabbing a coin, and maybe doing it a few times. The manager would then figure out the value that's changing in memory (presumably the sector that stores your coin amount), create the "cheat", and then you would enable it and watch your coin value go up.
jasomill 2y ago
Incidentally, Skies of Arcadia Legends on Dolphin is fantastic: https://www.youtube.com/playlist?list=PLwH1xJhcXG0dBlmWL_DTuKyHILksdH8jn https://www.youtube.com/playlist?list=PLwH1xJhcXG0dBlmWL_DTu...
djmips 2y ago
And old skool 'trainer' tools on PC. Someone more familiar that myself could give better information but I remember trying them out in the early 2000s and remarking how they reminded me of GameShark for PC