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movax · Joined: 03 Jan 2007 Posts: 4

Hey all, I'm in the process of writing a PSX <-> PSP savegame converter (Standalone from CWCheat), and I'm having trouble using the decrypt sample...

I can compile it just fine (using cygwin environment under WinXP), get the .PBP & .SFO, but it will not run on the PSP (Black screen). Removing the portions of the code that depend on the "-lpspsvchnnl" in the Makefile allows it to run (I stuck a test printf("test") at the beginning of the main loop, and it appeared).

PSP was a 1.5 flashed to the 3.02 OE-B (please tell me that doesn't cuase problems...?), and I've been attempting runs under the GAME150 (1.5 fw) folder. Something wrong on the PSP's end, or PC end?

adrahil · Joined: 16 Mar 2006 Posts: 277

Homebrew chnnlsv save game support is broken right now in 3.x

movax · Joined: 03 Jan 2007 Posts: 4

Broken eh? Leads me to two questions, 1. seems like there are tools that are still using that under 3.xx, and 2. I thought the point of OE-B was to allow homebrew to run under the 1.5 kernel by being placed in the GAME150 directory?

pspwill · Joined: 17 Nov 2005 Posts: 51

Didnt the savedata samples only work on 2.X under eloader?

Fanjita · Joined: 28 Sep 2005 Posts: 217

Correct, the necessary API is only available in VSH mode.

Presumably you could fairly easily load the required module from v1.5-style homebrew if you wanted to, though.

And I seem to recall someone was once going to reverse engineer the ChnnlSv functions and port them to something usable from game mode, but I don't remember who, and I don't believe they ever finished it.
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movax · Joined: 03 Jan 2007 Posts: 4

VSH mode? Forgive me, I just got my PSP less than a month ago and am trying to readup all the homebrew tuts I can. :) Got basic text I/O down, inputs & stuff, was hoping to move on now, heh.

Fanjita · Joined: 28 Sep 2005 Posts: 217

The PSP can boot into 3 basic modes : VSH, Updater and Game.

VSH is what is running when the XMB is active, and so it is the mode that exploits based on TIFF etc. end up in.

Game is what the PSP kernel launches UMDs in, and EBOOTs, if you manage to coax it into loading an EBOOT by itself.

The different modes have different sets of modules loaded by default. The decryption sample happens to need the ChnnlSv API, which is loaded (by default) under VSH only. Hence, it won't work outside of the TIFF exploit, without some additional effort.
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movax · Joined: 03 Jan 2007 Posts: 4

Ah, thanks for the clarification/explanations of modes.

Is there a tutorial that lists these different modes, or how to use certain exploits to execute homebrew code?

Fanjita · Joined: 28 Sep 2005 Posts: 217

Not as far as I know.

For running code via the TIFF exploit, you can grab the TIFF SDK from www.noobz.eu, it does most of the work for you.
_________________
Got a v2.0-v2.80 firmware PSP? Download the eLoader here to run homebrew on it!
The PSP Homebrew Database needs you!