Master file table

The master file table stores all data files used by the game (graphics, sounds, text, scripts, maps, and more). It is located near the end of the ROM. The MFT contains directories, and each directory contains files. Directories are identified by a 4-byte ID, files are identified by a 2-byte ID. Neither file names, nor subdirectories are supported.

struct mft_header {
    u16 id_low;
    u16 id_high;
    mft_directory* directory;
};

// NOTE: This applies to all directories, EXCEPT for the script directory. That has its own format.
struct mft_directory {
    u32 num_entries;
    u32 offset_to_id_array;      // Relative to the start of this struct
    u32 offset_to_file_array;    // Relative to the start of this struct
    u16 id_array[num_entries];
    u32 file_array[num_entries]; // Entries are relative to the start of this struct
    // File contents follow
};

// Return pointer to start of file with the specified id.
void* mft_get_file(mft_directory* dir, u16 id) {
    u16* id_array = (char*)dir + dir->offset_to_id_array;
    u32* file_array = (char*)dir + dir->offset_to_file_array;
    u32 index = index_of(id_array, id);
    u32 file_offset = file_array[index];
    return (char*)dir + file_offset;
}

// See table below for address
mft_header mft_headers[11];

MFT Address

The mft_headers[] array starts at the following addresses:

Game	Address
Boktai 1 (J)	0x085a1584
Boktai 1 (U)	0x085b02c4
Boktai 1 (EU)	0x0856e97c
Boktai 2 (J, Rev. 0)	0x085b0ce4
Boktai 2 (J, Rev. 1)	0x085b0d90
Boktai 2 (U)	0x085abbc0
Boktai 2 (EU)	0x085b1874
Boktai 3 (J)	0x08614d6c

MFT Directories

The following directories exist:

id_low	id_high	Description
0x5130	0x9225	TODO
0xe53e	0xc305	Tile maps
0xac2c	0xaf05	Maps
0xd710	0x9305	Palettes - 20 byte header (ignorable?) followed by 0x200 bytes of raw GBA palette data
0x4f2d	0xcee5	TODO (tile sets?)
0x6d24	0xa705	Font
0x0a4d	0xcf05	TODO (tile sets?)
0x2117	0x9b05	TODO (tile sets?)
0x5f29	0xc8e5	Sprite sets
0x4679	0x9a65	Sprite set palettes
0x41f5	0xa8d9	Script directory (Boktai 1)
0xa41e	0xa8d9	Script directory (Boktai 2)
0x49bc	0xa8d9	Script directory (Boktai 3)

Tools

• Bokasm: Can extract the MFT of Boktai ROMs