This guide contains explanations to reverse engineering a PSP game to create a translation patch, using as example the “digivice ver. portable psp” ISO. (it has plenty of images to make the understanding easier)

Warning: Some files and/or methods of this project might be only as a proof of concept, hence they lead nowhere further on. If you don’t know why something is there, it’s probably that.

Considerations

• This is a PDF version of: https://github.com/Bunkai9448/digipet_PSP. To help clarity and visibility.
• This guide is, also, basically a cleaned-up version of: https://www.romhacking.net/forum/index.php?topic=35699.msg437896#msg437896
• You must provide your own game files. Please do not ask here for them.

INDEX

• Extra Tools required
• First Steps
• Working with the CPK file
• Text File
• More unpackaging inside the CPK
• Images and GIM files
• Remaining text in the Eboot
• The Font
• Repackaging the CPK
• System Messages
• Last Steps
• Extra: Making the patch
• Extra 2: Making a cheatcode
• List of References
• Author
• Special thanks
• License

To give a brief idea, here’s Extra Tools required list

• https://www.ppsspp.org/index.html (PPSSPP emulator & debugger).
• https://www.romhacking.net/utilities/1218/ (UMDgen).
• https://www.romhacking.net/utilities/818/ (Crystal Tile 2).
• CriPackTools & Cripack maker / crifilesystem (some versions don’t work and not all can be shared).
• https://github.com/Kingcom/armips (armips program).
• http://aluigi.altervista.org/quickbms.htm (quickBMS program).
• GimConv (you have to find this tool on your own).
• https://www.romhacking.net/utilities/1225/ (DecEboot to decrypt EBOOT.BIN).
• http://aluigi.org/bms/parse_exe.bms (to unpack the decrypted EBOOT.BIN and work with the text part better).
• https://www.romhacking.net/utilities/598/ (xdelta and xdeltaUI to create the patch easily).