need help in debugging ps2 titles

[thereal_zap]

i would like to know what kind of setup and software i'd need to properly debug ps2 titles to try and get some titles working. i'm quite adept at low-level asm debugging on the pc, but i don't know how exactly to do this with a ps2 game.

do you use pcsx2 and hook in there somehow? any changes or tweaks i've made to elf files have involved disassembly, guesswork, trial and error. but it'd be nice to monitor a game in real time to see what's really happening.

just like crazyc has found issues with some games where at some point the game points to a void* buffer that doesn't exist and you've fixed that (ala ratchet and clank). my question is: 'how the hell did you figure that out?' 'what's your setup?'. perhaps some of you guys have ties to or are part of real development companies with real development ps2's, etc.

in any case, i'd just like to know what i'd need to set this up (software, hardware, etc) so i can perhaps be of assistance in getting some games working.

you never know until you ask

thanks in advance for any help you guys can lend on this subject

[crazyc]

'how the hell did you figure that out?'

Pcsx2, ps2dis and a lot of SIF call traces.

[thereal_zap]

Pcsx2, ps2dis and a lot of SIF call traces.

cool, it's good to know that you're using the first 2 tools to do pc side work which means it's not a big setup

SIF call traces? SIF? what's that?

even when running stuff thru pcsx2, how to you actively debug the game with it? or, is it that you're not debugging and you're just going over some available dumped log or something that pcsx2 can produce? maybe that's what you mean by checking out all those calls.

i suppose another valid question would be that when you're checkout out games within pcsx2, are you first loading the HDL ELF and then booting a game from there? (can pcsx2 run HDL, i guess is the question. and if so, how do you configure your hdd so that it can be read by the emulator)

thanks for the reply

[crazyc]

SIF call traces? SIF? what's that?

SIF stands for "System Interface". It's the interface between the IOP and the EE. PCSX2 has an option to log all RPC calls passing through the SIF. The problem with Ratchet and Clank was split between both processors so I had to log a large chunk of the traffic to figure out what was going on.

even when running stuff thru pcsx2, how to you actively debug the game with it?

Sure I'm actively debugging it until I have an idea of whats happening. The Crash Twinsanity problem is a good example. Before I got HDLoader working with PCSX2, I tried adding printf's to the area in the binary that I thought it was crashing. Then, I watched the output on the PS2's serial line. Problem was is that it was crashing in the IOP reset code and AFAIK there's no way to get the output from the IOP. After I got HDLoader working, I could just run PCSX2 until it crashed. The strange stack address was obvious then in the register window.

i suppose another valid question would be that when you're checkout out games within pcsx2, are you first loading the HDL ELF and then booting a game from there?

Yes.

[thereal_zap]

thanks for your replies crazyc. i'm gonna have to start playing with pcsx2 and familiarize myself with it. hopefully, i'll be able to put 1 and 1 together and figure some stuff out

[crazyc]

thanks for your replies crazyc. i'm gonna have to start playing with pcsx2 and familiarize myself with it. hopefully, i'll be able to put 1 and 1 together and figure some stuff out

Is there some particular game you are going to work on?

[thereal_zap]

Is there some particular game you are going to work on?

the only game that i own right now that isn't working on hdd is sc:chaos theory. i'd really like to see what's going on there. so probably that would be the first one i'd check out. i haven't bought any new games in awhile, so it'll be a bit b4 i can look at some of these newer ones.