Exploit boot with PS2 CD(requires modchip)
I've just made a weird discovery, quite by accident. I have a 'Ripper 2 Gold' modchip in my PS2, and for booting PS1 games this requires me to 'double-click' the reset button on the console itself. Doing so restarts the console with the chip in PS1 mode, meaning that the bios will 'see' any CD as a legal pressed PS1 CD, regardless of its real nature.
Today I accidentally 'glitched' on the reset button, with a PS2 CD in the tray, and was astonished to find that this resulted in my mc0: 'exploit' copy of LaunchELF starting...
This was surprising for two reasons:
1: That CD is a PS2 CD. It's SYSTEM.CNF doesn't have the same commands as one for PS1. (BOOT2 instead of BOOT)
2: That CD has NO normal disc ID whatever, not even a 'PSX.EXE' file. It's a homebrew disc I made myself, containing only HDL.ELF, SYSTEM.CNF, and DUMMY.BIN (just a size boster). So, according to available info on the exploit this CD should NOT have been accepted as a trigger disc...
Further experiments show that the same thing also works with other PS2 CD-Rs (not DVDs), regardless of the contents of SYSTEM.CNF, as they too trigger the exploit when booted with the mod-chip in PS1 mode. (Tested with some DVD-rips on CD-R.) This seems to work consistently with the "Ripper 2 Gold", though I can't be sure about other mod-chips.
Of course, these interesting findings aren't directly useful, since those who really need exploit booting are those without any mod-chip at all. Still, perhaps someone else can find these results useful as a clue to how future exploits may be improved. Also, they may be of help to those with mod-chips that don't support Dev1 booting (if this works there ?).
Best regards: dlanor