1. Escape1975

    OP Escape1975 Advanced Member
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    Does anyone know what the layout of SYSTEM and USER partitions are?
    Specifically what cluster size the FAT32 system uses on both partitions ...
     
  2. eliboa

    eliboa GBAtemp Regular
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    From boot sector (SYSTEM & USER) :
    512 bytes per sector
    32 reserved sectors
    32 sectors per cluster (cluster size: 16 KB)
    Number of FAT : 2
     
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  3. Escape1975

    OP Escape1975 Advanced Member
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    Excellent, thanks for the info ...

    While looking at USER partition and using HacDiskMount I've noticed that when you re-format it from windows the FAT32 filesystem changes a little bit, and it's no longer considered a FAT32 (BitLocker) because windows adds a boot sector to it ...

    Wondering if someone has a USER.BIN backup that they could point me towards so I can examine
    the differences and how to handle editing USER and SYSTEM partitions without altering them too much ...
     
  4. eliboa

    eliboa GBAtemp Regular
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    There's always a boot sector in reserved sectors, that's how FAT works. You should try NxNandManager to re-format USER, it'll recreate boot & info sectors with original values (as much as possible).

    About your BitLocker tag problem, maybe there's a value somewhere in info sector that describes partition's encryption mode. USER, SYSTEM, SAFE, PRODINFO & PRODINFOF are all encrypted with AES-XTS mode (decryption uses BIS keys), BitLocker uses AES-XTS too, if I remind correctly. I guess that's why Windows labels your partition "BitLocker" even though it's not encrypted with BitLocker.
     
    Last edited by eliboa, Jan 20, 2021
  5. Escape1975

    OP Escape1975 Advanced Member
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    Ok I'll try messing with that, the BitLocker flag shows up in Winhex when I open the SYSTEM image part of the dump,
    however it doesn't when I open the USER image part of the dump ...

    It looks like the SYSTEM and I'm also assuming USER is formatted differently than my USER is now,
    that is I shouldn't see "MSDOS 5.0" and "Press any key to reboot" anywhere on the filesystem :)

    Also the SYSTEM boot identifier is EB E9 90 instead of Windows's EB 58 90
     
    Last edited by Escape1975, Jan 20, 2021
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