Need help with file encryption for Tokimeki Memorial Girl's Side 3

Discussion in 'PSP - Hacking & Homebrew' started by jjjewel, Apr 29, 2014.

  1. jjjewel
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    jjjewel GBAtemp Maniac

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    I'm working on English translation for Tokimeki Memorial Girl's Side 3 and got a major problem that the patch with English translation only worked with emulators (tested with PPSSPP and JPCSP) but not on any PSP (tested with firmware 6.60 Pro B10 and 5.50 prome-4).

    I could narrow down to the decrypted INSTALL.DAT that cause the problem. The original file was encrypted but I needed to add translation and edit some graphics in this file so it needed to be decrypted. I used JPCSP's decryption to decrypt it. (Which gave the same result as a file decrypted with pgdecrypt.exe.)

    Anyone ever experienced this kind of problem? And how should I fix it? As far as I know, we can only decrypt PGD file but can't encrypt it back.

    Pic below shows the file that caused trouble. Just decrypt the original file and put it back to ISO, the game will freeze after you name the heroine. (Before and during the naming, the game uses graphics, text, and voice from USRDIR\cdimg0.img. After that point, it will need to load background from INSDIR\INSTALL.DAT and that's when the game turns into black screen and freezes on PSP but it works fine on emulators.)

    gs3P.png

    The file index in \USRDIR\cdimg.idx is used for both cdimg0.img and INSTALL.DAT. I'm not sure if I'm supposed to change anything there to tell it that INSTALL.DAT isn't encrypted.

    If anyone know anyway I can fix this problem, please help. T_T Thank you very much.

    Most of the script text is in USRDIR\cdimg0.img and as far as I tested, this part didn't have any problem. Eboot.bin also needed to be decrypted, but decrypted eboot.bin didn't cause any problem either.
     
  2. thexyz

    thexyz Member

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    Decrypt eboot.bin and change 25 80 02 02 at offset 0x2847C to 00 00 00 00.

    upd. wait, psp seems to lock up when entering out of sleep mode, I'll have to investigate further
    upd2 it seems one of my plugins was causing the crash, so nevermind
     
  3. jjjewel
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    jjjewel GBAtemp Maniac

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    Thank you very much. I'll make a new patch and test it. I'll post updates later in this thread. :wub:
     
  4. jjjewel
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    jjjewel GBAtemp Maniac

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    Update: Confirmed that it now works on PSP. Yay~! Thank you very much. I'll ask my friends to check a few things and if there's no problem, I'll announce the project soon. :D
     
    rubenz and oji like this.