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ROMhacking-PSP_basics – Document

Document: ROMhacking-PSP_basics
Released by:
Version: 0.9
Last updated: March 27, 2023
Downloads: 3

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.


  • This is a PDF version of: To help clarity and visibility.
    • You must provide your own game files. Please do not ask here for them.


    • 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

    • (PPSSPP emulator & debugger).
    • (UMDgen).
    • (Crystal Tile 2).
    • CriPackTools & Cripack maker / crifilesystem (some versions don’t work and not all can be shared).
    • (armips program).
    • (quickBMS program).
    • GimConv (you have to find this tool on your own).
    • (DecEboot to decrypt EBOOT.BIN).
    • (to unpack the decrypted EBOOT.BIN and work with the text part better).
    • (xdelta and xdeltaUI to create the patch easily).
Special thanks

Fothsid (first guidance about the headers)

Mugi (guidance about file structure and some scripts; Info, Data and guidance for System Messages)

Ethanol (guidance about Font, GIM, Gimconv config snippet and help fixing extract/insert mistakes)

kokibits (this project uses their PSP plugin for the syscalls)

前田太尊 (maeda taison) (betatester)

All the authors of the tools and documents used in this project.
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