Expanding Eboot Size

This is a place to post tech details and informative documents about romhacking PSP games.
Post Reply
User avatar
zeromonkey
Hacker, script editor and control freak
Posts: 486
Joined: Thu Mar 05, 2015 3:10 pm
Location: Tennessee

Expanding Eboot Size

Post by zeromonkey » Fri Sep 18, 2015 8:10 pm

Has anybody tried this before? I was just wondering if it was even possible. It really could come in handy to throw a few large chunks of blank space on the end of the file. I have tried to look for some documentation about the setup of the files but I haven't found the answer I am looking for and that is how does the file know how big it is? I would think somewhere in the header information would be that kind of stuff but either lack of knowledge or just being brain dead when attempting it, I haven't figured it out yet.

flamethrower
Programmer
Posts: 995
Joined: Mon Mar 09, 2015 3:03 pm

Re: Expanding Eboot Size

Post by flamethrower » Fri Sep 18, 2015 10:59 pm

If JamRules can't do it, then no one can.
You could try asking Kelebek on GBAtemp.

JamRules said he got it to work but not on a real PSP.

If you want to do your own investigation, I think I have an idea as to where you could start. But I myself didn't get very far.

EBOOT. What is that, really? It is the name of the executable file.
When you give the PSP the command to start a disc or file:
1) Read header information.
1A) Where can I find the executable (within disc or ISO file).
1B) Where to load the executable in memory.
1C) Where to set the instruction pointer within the EBOOT so that the program will start running.
2) Load the EBOOT into the specified memory address, set the instruction pointer and begin program execution.

The executable is in a format called ELF. It is well documented out there on the internets.
Look for a program called readelf. It will tell you about the format.
PSP uses standard ELF. There is nothing special about it. What I can't tell you is how to modify.

See this thread on GBAtemp. Post within it if you like.
http://gbatemp.net/threads/psp-asm-hack ... nt.374967/

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest