Booting a game directly from the executable?

[BitRain]

As far as I know it isn't possible in PCSX2 right now, but in theory I'd like to know if it's possible to launch a game directly from it's PS2 executable, ie. SLUS_xx.66/65/64.

I know these executable files then "activate" the boot.elf in the BIOS (?), I might be wrong but that's my understanding of it, I'm asking because emulators like Dolphin and Xenia can load the game executable directly from loose files (extracted ISOs, for example), this allows for pretty easy modding and you can then edit the executable with IDA to change small parts of the game, like this: 
a modified Half Life ISO with a custom executable that allows for autojumping, useful for bunnyhopping and enabling some PC-Like cheats.
https://www.youtube.com/watch?v=Vg0AlSyFqdQ

From my experiences modding PS2 titles, the game doesn't seem to work if you replace a file that's either much bigger than the original or much smaller than the original in the ISO/disk, I'm not sure if this applies to every game but it certainly sucks, which is why I'm asking if I can boot from the executable, it makes modding so much easier. 

Is this some kind of hard-coded checksum in the PS2 firmware that's been emulated to match the way the real PS2 works or is it some kinda anti-piracy measure?

[Bositman]

System-> Run ELF?

[BitRain]

Well, I didn't know that would work, I assumed running ELF files meant exclusively ELF files and not .66, .65, etc etc.

But it still doesn't work.

Here's a log:
http://pastebin.com/FBSMpPP2

then this loops for a while:

Code:

(pxEvtQueue:PauseCoreThread) Posting event! (pending=0, idle=0)
(pxEvtQueue:PauseCoreThread) Executing... [Cancelable]
(pxEvtQueue:PauseCoreThread) Event completed in 749ms
(pxEvtQueue:PauseCoreThread) Posting event! (pending=0, idle=0)
(pxEvtQueue:PauseCoreThread) Executing... [Cancelable]
(pxEvtQueue:PauseCoreThread) Event completed in 820ms

The window says it's running at 65fps but nothing shows, no sounds, nothing.

[refraction]

You can't really run extracted games like that, it doesn't work very well as it needs to load all the IRX files n such in a specific order. If you modify your game you will have to compile it in to a new ISO file

[BitRain]

Which doesn't really work anyway right? You need to have it be in a very specific form of ISO in order for it to boot correct?

[refraction]

kind of yeh, it needs to be in the correct order so the IRX and CNF files come before the ELF, then all the other data can go afterwards.

[BitRain]

Well that's pretty *****.


But theoretically, would it be possible for PCSX2 to figure that out on it's own? Or would it be very game specific?

[refraction]

Well PCSX2 does what the PS2 would do, which is that It's a real pain, I agree!