Deci2 debug on pcsx2 - useful to ps2skd?

[cory1492]

I was looking around for random ps2 projects (mmm more source to digest) and found the sourceforge project pcsx2 with an interesting area in the source code:

http://cvs.sourceforge.net/viewcvs.py/p ... x2/RDebug/

Its been around for a while I guess, but hey, maybe there is something in there that could be useful?

[mrbrown]

Anything DECI2 comes from the official SDK, which means it doesn't belong in PCSX2 in the first place.

[Guest]

Anything DECI2 comes from the official SDK, which means it doesn't belong in PCSX2 in the first place.

I know very little about DECI2, other than that its some protocol thingy. Is this something that could have been reversed without the assist of Sony docs or is that too terribly unlikely, making it hot to touch ?

[cory1492]

I figure from other posts on debugging that DECI2 is somewhat useless to us unless we have an actual TOOL, but who knows? Just thought Id share.

[mrbrown]

Is this something that could have been reversed without the assist of Sony docs or is that too terribly unlikely, making it hot to touch ?

Yes to the latter - there is no way they could've come across DECI2 information without official docs or a T10K BIOS. Even the BIOS isn't enough without the docs.

Besides there is nothing DECI2 can do for consumer PS2s. You are much better off fixing up the GDB stub.

[cory1492]

Hrmm, I seem to have found another alternative for debugging on consumer ps2, but I dont know yet how much of a pain its going to be to set up (I happen to have a G.2 here in fact..)

from www.ghost2.net

Any PS2 modded with G.2 will also act as a DEBUG STATION, supporting variety of tools (you can execute programs step by step, set break points, see the registers etc. and this is not a software emulation - this is on retail ps2 hardware)

the chip has onboard connections for what appears to be a serial connection (tx rx etc) but I have yet to see some explanation on how to effectively use it as a Debug Station...

edit:
ahh, the wonders of forum search engines:

In order to build a strong Community around the G.2, we decided to think "OPEN SOURCE" and therefore added a Debug Interface to the Design, to make it easier for the developer to produce their own Flash Files.
Its High Speed Serial Interface that operates at 1Mbs, has internal independent receive and transmit buffers and can be used for anything, like dumping ps2 memory, sending messages about current operation mode, checking CPU registers etc. - programmer will decide what to use it for. Unlike USB, Memcard or Firewire links this Debug Tool doesn't need any drivers or software to be loaded and operates on hardware level.
In other words developers have more control over what's going on inside of ps2

We plan to release chip algorithm and HW registers as well as source code (for flash file, not main FPGA), like XBMC or Xbox Linux Does. In order to have a Community of Developer working on new Flash File. This way, code will be released as a Source and it will be up to the end user to compile it and use it.

Hopefully there is some measure of protection for "retail" code along with this, but I kinda doubt it.

[Guest]

Well, there is already an unused serial I/O on the EE. There is likely one on the IOP but we don't know where, but there is also a serial I/O on the SPEED ATA/IDE chip of the network adaptor, so the PS2 is pretty well covered as far as SIO. But in any case, using any of them still requires soldering skills so ppl who have this G2 thingy may have a leg up.

[mrbrown]

If they meant DEBUG STATION as in Test Station then we use either a FireWire cable or PS2 Network Adapter to debug our game on it. I'm not jumping out of my seat for a 1Mbit connection when the network adapter is much faster. I could see if the entire mod was self-contained where it had it's own interface that could remotely reset the EE and IOP - then they would have something closer to the TOOL's builtin Pentium II.

Despite what they claim, ps2link turns the PS2 into a DEBUG STATION more than anything else out there. There's a new gimmick from modchip companies every other month it seems. Wasn't last month's developer's chip the Crystal Chip? What happened to it?

[cory1492]

I will let ya all know if the g2 offers anything really useful then - when I find out that is.

[yulius]

Is there a patch for GDB to handle the ps2 gdb stub? I got gdb working w/ the stub, but I want to make gdb not print out the extra information.

Thanks for the help.