general info, from CMP :
First I'd like to give you some information about what hackers do here. I'll put it into laymen's terms so I hope the hackers will excuse my use of non-technical adjectives.
Each game has a "heart" that it runs. It's called eboot.bin. This files contains most/all the game data itself. The game uses certain commands and values inside this eboot.bin to send data to the ps3's memory (RAM, whatever you want to call it). What we do here is take the eboot.bin and de-crypt it into an .elf file (game.self) we can work with. After it's decrypted, the laborous job of finding certain "values" starts. Hackers will use the CMP Auto Tools/ or other tools, to look for values. These are usually "max" values. Because the game puts limits on hp, money, stats, right? If the hacker knows the value of money is 59 999, then they can look for that value inside the decrypted eboot.
Once the value is found, you can manipulate the command code lines surrounding the value. You can sometimes trick the eboot into loading this "max" value instead of the regular one.
Once all changes have been made to this eboot, we can then re-encrypt it back to eboot.bin. Now the resulting eboot.bin isn't the same as the original b/c there is some security issues we can't replicate easily. So we need a way to put this eboot.bin and a few other basic files into the ps3's hard drive.
This is where package making comes in. We can put the eboot and basic other files into a package and install it to the ps3's hard drive. Once there, depending on the type of package, the disc will give preference/work with the package we've installed. Once the eboot with the modified cheat codes is loaded, you get to have your fun...lol.