pureikyubu/Docs/RE/bb2.txt

// BB2 (Boot Block 2) structure

#define OS_BB2_OFFSET   0x400       // disk offset

typedef struct
{
    u32     bootFilePosition;       // main DOL executable
    u32     FSTPosition;            // default FST
    u32     FSTLength;              // default FST size (in bytes)
    u32     FSTMaxLength;           // size of biggest additional FST
    u32     userPosition;
    u32     userLength;
    u8      padding0[40];           // reserved, should be 0
} DVDBB2;