ps2-packer

ATTENTION

If you are confused on how to start developing for PS2, see the getting started section on the ps2dev main page.

Overview

Just like UPX, this tool is designed to help you create packed ELF to run on the PS2.

Modules

Is being done following a modular design, so anybody can write any kind of module to it. It actually contains:

zlib module.
lzo module.
lz4 module.
lzma module.
null module, for demo purpose only.

TODO

Changing current module design to pass on arguments.
Write a proper documentation about "how to write new modules".
Add RC4 modules.

History

Well, I wrote this piece of junk in one day, because Drakonite said me zlib would be better than lzo, and that it would be quite a challenge to get it working for PS2. I wanted to see if he was right :)

Source code and legal stuff

This code is covered by GPL. Actually, I don't give a shit about licenses and stuff. If you don't like it covered by GPL, just ask me, and we'll change it. The only problem is it uses modified version of a lot of GPLed code, so...

This code was inspired by various sources, especially sjcrunch's main.c, and sjuncrunch. Some idea from mrbrown too :)

Beeing a ps2dev.org developper got me banned from ps2ownz.com's website. Thus, as a special exception to the GPL, since I can not go on their forums, and react and help people about that software, I to NOT give them the autorization to mirror these packages on their website, only to link to the homepage of this project, that is, http://www.nobis-crew.org/ps2-packer nor are they authorized to support their users on their forums on questions about that software.

I actually know they won't give a shit about these restrictions, but I felt like proceeding so. If you want real and legit ps2 development, go on the genuine ps2dev website, that is, http://ps2dev.org

How it works

  Usage: ps2-packer [-v] [-b X] [-p X] [-s X] [-a X] <in_elf> <out_elf>

  Options description:
    -v             verbose mode.
    -b base        sets the loading base of the compressed data. When activated
                      it will activate the alternative packing way. See below.
    -p packer      sets a packer name. lzma by default.
    -s stub        sets another uncruncher stub. stub/lzma-1d00-stub by default,
                      or stub/lzma-0088-stub when using alternative packing.
    -a align       sets section alignment. 16 by default. Any value accepted.
                      However, here is a list of alignments to know:
        1 - no alignment, risky, shouldn't work.
        4 - 32-bits alignment, tricky, should on certain loaders.
           16 - 128-bits alignment, normal, should work everywhere.
          128 - 128-bytes alignment, dma-safe.
         4096 - supra-safe, this is the default alignment of binutils.

Now, you have to understand the mechanisms.

In normal mode, the output elf will contain one program section. Its loading location depends on the selected stub. For example, with a stub loading at 0x1d00000, compressed data will be located below that address. I provide

However, if you specify a base loading address on the command line, the data will be forced to reside at a certain location. That's the alternative packing method. The output elf will contain two program sections. The first one will be the uncruncher stub. The second section contains the packed data, loaded at the address you specified.

So, depending on your needs, just move the data around, to get the desired results.

Examples

~$ ./ps2-packer ./ps2menu.elf ./ps2menu-packed.elf
PS2-Packer v0.3 (C) 2004 Nicolas "Pixel" Noble
This is free software with ABSOLUTELY NO WARRANTY.

Loading stub file.
Stub PC = 01D00008
Loaded stub: 0000057C bytes (with 00000204 zeroes) based at 01D00000
Opening packer.
Preparing output elf file.
Packing.
ELF PC = 00100008
Loaded section: 0006B438 bytes (with 0033CB72 zeroes) based at 00100000
Section packed, from 439350 to 162565 bytes, ratio = 63.00%
Final base address: 01CD84E0
Writing stub.
All data written, writing program header.
Done!

~$ ./ps2-packer -b 0x1b00000 ./ps2menu.elf ./ps2menu-packed-alt.elf
PS2-Packer v0.3 (C) 2004 Nicolas "Pixel" Noble
This is free software with ABSOLUTELY NO WARRANTY.

Using alternative packing method.
Loading stub file.
Stub PC = 00088008
Loaded stub: 0000057C bytes (with 00000204 zeroes) based at 00088000
Opening packer.
Preparing output elf file.
Actual pointer in file = 000005FC
Realigned pointer in file = 00000600
Packing.
ELF PC = 00100008
Loaded section: 0006B438 bytes (with 0033CB72 zeroes) based at 00100000
Section packed, from 439350 to 162565 bytes, ratio = 63.00%
All data written, writing program header.
Done!

$ ./ps2-packer -p lzo ./ps2menu.elf ./ps2menu-packed-lzo.elf
PS2-Packer v0.3 (C) 2004 Nicolas "Pixel" Noble
This is free software with ABSOLUTELY NO WARRANTY.

Loading stub file.
Stub PC = 01D00008
Loaded stub: 000006FC bytes (with 00000204 zeroes) based at 01D00000
Opening packer.
Preparing output elf file.
Packing.
ELF PC = 00100008
Loaded section: 0006B438 bytes (with 0033CB72 zeroes) based at 00100000
Section packed, from 439350 to 237121 bytes, ratio = 46.03%
Final base address: 01CC61A4
Writing stub.
All data written, writing program header.
Done!

Comparing Results

$ ls -l ps2menu.elf ps2menu-packed*
-rw-r--r--    1 pixel    pixel      444240 Aug 12 23:33 ps2menu.elf
-rw-r--r--    1 pixel    pixel      164124 Aug 13 15:07 ps2menu-packed.elf
-rw-r--r--    1 pixel    pixel      164125 Aug 13 15:07 ps2menu-packed-alt.elf
-rw-r--r--    1 pixel    pixel      239064 Aug 13 15:08 ps2menu-packed-lzo.elf

Bugs and limitations

It's poorly coded :-P
Stubs have to be in one single program header.

How to compile

Current compilation options requires libz.a and libucl.a to reside at /usr/lib/libz.a and /usr/lib/libucl.a (I do that only to statically link the zlib and ucl with the final software, so it will run everywhere) So, if it doesn't match your system, change that line into the Makefile. Afterward, a simple make should do the trick in order to compile everything, provided you have the full ps2 toolchain, with the PS2SDK variable pointing to your ps2sdk directory, and ee-gcc under your path.

Don't look at the dist target in the Makefile, it's only for me to build the various packages.

Author

Nicolas "Pixel" Noble \pixel@nobis-crew.org - http://www.nobis-crew.org

Where to find

The "official" webpage for this tool is at on my personal webspace:

http://www.nobis-crew.org/ps2-packer/

However, you can find the latests CVS changes into ps2dev's CVS:

http://cvs.ps2dev.org/ps2-packer/

Community

Links for discussion and chat are available here.

Thanks and greetings

They go to adresd, blackd_wd, drakonite, emoon, gorim, hiryu, herben, jenova, linuzapp, oobles, oopo, mrbrown, nagra, neov, nik, t0mb0la, tyranid

and maybe a few other people I forgot at #ps2dev :)

Big special thanks to LavosSpawn who helped me reducing the asm stub ;)

ps2dev / ps2-packer

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