Custom disc setup - Slim
If you intend to make your own image containing additional homebrew / modified initial loader, please read on.
Step 1: Copy your homebrew
Once you've identified your console's DVD Player version, copy all of the homebrew you would like to include on the disc into that directory in the Filesystems (EG: Filesystems/All PS2 slims (3.10 + 3.11) - English language/ is the one that supports all slim consoles).
Step 2: Make an image
Once you've placed all the homebrew files you'd like into the directory, generate a UDF (ISO9960/UDF hybrid also works) image of the directory (so VIDEO_TS is in the root).
On Windows, you can use a GUI like ImgBurn to make an disc image. It will give a warning that VIDEO_TS.BUP is missing, but just click continue anyway (PS2 doesn't require this file).
On Linux the easiest way is probably to use genisoimage as it comes pre-installed on many Linux distributions like Ubuntu. Run the following on terminal (where exploit.iso is the output and Filesystem/All PS2 slims (3.10 + 3.11) - English language is the directory containing VIDEO_TS and any homebrew):
genisoimage -udf -o exploit.iso "Filesystems/All PS2 slims (3.10 + 3.11) - English language"
Step 3: Test and burn
I would recommend you test in PCSX2 first, but since PCSX2 doesn't support loading the DVD Player, you have to decrypt and repack it yourself, which is beyond the scope of this README. With that said, if you aren't touching anything in VIDEO_TS, there shouldn't really be any reason for the exploit to fail.