Posted: 2/11/2018 8:50 PM
Post subject: Need help with SNES disassembly
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qflame
He/Him
Player (11)
Joined: 11/19/2017
Posts: 6
Hello, I'm working on reverse engineering a SNES game to produce a TAS, but I've ran into an issue. A lot of the game's code is within a set range of addresses, specifically 800000 - 9FFFFF. I've loaded up the ROM in IDA and it has found all of those subroutines. However, after taking a look at the disassembler in bizhawk, sometimes the program counter is at much lower addresses like 1984A3, 93B0, 1B978, etc. The disassembler can show me a small window of the assembly code in that range, but there appears to be no way to navigate through, save the code to a file, etc. Normally this wouldn't be a problem as I'm doing a lot of the work in IDA, but IDA does not pick anything up in these ranges and I can't seem to get it to recognize any additional code. Is there some way to get the disassembler in bizhawk to navigate around the code? Is there a better way of doing this in general? Any help is appreciated.
Posted: 2/11/2018 8:54 PM
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Masterjun
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Site Developer, Skilled player (1971)
Joined: 10/12/2010
Posts: 1179
Location: Germany
Exotic platforms TAS of 2020 Speedy TAS of 2018 PC TAS of 2018 Glitchy TAS of 2015 TASer of 2014 SNES TASer of 2014 TAS of 2014 SNES TAS of 2014 Funny TAS of 2014 Glitchy TAS of 2014 TASer of 2013 SNES TASer of 2013 NES TAS of 2013 SNES TAS of 2012 Funny TAS of 2012
Not really an answer but keep in mind that the SNES has a lot of address mirrors, meaning for example the $0093B0 you see is the same as $8093B0. Take a look at a memory map.
Warning: Might glitch to credits I will finish this ACE soon as possible (or will I?)
Posted: 2/11/2018 9:13 PM
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qflame
He/Him
Player (11)
Joined: 11/19/2017
Posts: 6
I think that does answer my question, thank you!
Posted: 2/11/2018 9:28 PM
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feos
Site Admin, Skilled player (1236)
Joined: 4/17/2010
Posts: 11268
Location: RU
NES TAS of 2011
Bizhawk's debugger is a joke, all bizhawk can actually do is trace logging. If you want to seriously dig into reversing a snes game, pick lsnes. Or MAME? O_O
Warning: When making decisions, I try to collect as much data as possible before actually deciding. I try to abstract away and see the principles behind real world events and people's opinions. I try to generalize them and turn into something clear and reusable. I hate depending on unpredictable and having to make lottery guesses. Any problem can be solved by systems thinking and acting.