1RGBFIX(1) BSD General Commands Manual RGBFIX(1)
2
4 rgbfix — Game Boy header utility and checksum fixer
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7 rgbfix [-jsVv] [-C | -c] [-f fix_spec] [-i game_id] [-k licensee_str]
8 [-l licensee_id] [-m mbc_type] [-n rom_version] [-p pad_value]
9 [-r ram_size] [-t title_str] file
10
12 The rgbfix program changes headers of Game Boy ROM images. It also per‐
13 forms other correctness operations, such as padding.
14 Note that options can be abbreviated as long as the abbreviation is unam‐
16 biguous: --verb is --verbose, but --ver is invalid because it could also
17 be --version. The arguments are as follows:
18 -C, --color-only
20 Set the Game Boy Color–only flag: 0x143 = 0xC0. If both this and
21 the -c flag are set, this takes precedence.
22 -c, --color-compatible
24 Set the Game Boy Color–compatible flag: 0x143 = 0x80. If both
25 this and the -C flag are set, -C takes precedence.
26 -f fix_spec, --fix-spec fix_spec
28 Fix certain header values that the Game Boy checks for correct‐
29 ness. Alternatively, intentionally trash these values by writing
30 their binary inverse instead. fix_spec is a string containing
31 any combination of the following characters:
32 l Fix the Nintendo logo (0x104–0x133).
34 L Trash the Nintendo logo.
35 h Fix the header checksum (0x14D).
36 H Trash the header checksum.
37 g Fix the global checksum (0x14E–0x14F).
38 G Trash the global checksum.
39 -i game_id, --game-id game_id
41 Set the game ID string (0x13F–0x142) to a given string of exactly
42 4 characters. If both this and the title are set, the game ID
43 will overwrite the overlapping portion of the title.
44 -j, --non-japanese
46 Set the non-Japanese region flag: 0x14A = 1.
47 -k licensee_str, --new-licensee licensee_str
49 Set the new licensee string (0x144–0x145) to a given string,
50 truncated to at most two characters.
51 -l licensee_id, --old-licensee licensee_id
53 Set the old licensee code, 0x14B, to a given value from 0 to
54 0xFF. This value is deprecated and should be set to 0x33 in all
55 new software.
56 -m mbc_type, --mbc-type mbc_type
58 Set the MBC type, 0x147, to a given value from 0 to 0xFF.
59 -n rom_version, --rom-version rom_version
61 Set the ROM version, 0x14C, to a given value from 0 to 0xFF.
62 -p pad_value, --pad-value pad_value
64 Pad the image to a valid size with a given pad value from 0 to
65 0xFF. rgbfix will automatically pick a size from 32 KiB, 64 KiB,
66 128 KiB, ..., 8192 KiB. The cartridge size byte (0x148) will be
67 changed to reflect this new size.
68 -r ram_size, --ram-size ram_size
70 Set the RAM size, 0x149, to a given value from 0 to 0xFF.
71 -s, --sgb-compatible
73 Set the SGB flag: 0x146 = 3. This flag will be ignored by the SGB
74 unless the old licensee code is 0x33!
75 -t title, --title title
77 Set the title string (0x134–0x143) to a given string, truncated
78 to at most 16 characters. It is recommended to use 15 characters
79 instead, to avoid clashing with the CGB flag (-c or -C). If both
80 this and the game ID are set, the game ID will overwrite the
81 overlapping portion of the title.
82 -V, --version
84 Print the version of the program and exit.
85 -v, --validate
87 Equivalent to -f lhg.
88
90 Most values in the ROM header are only cosmetic. The bare minimum
91 requirements for a workable program are the header checksum, the Nintendo
92 logo, and (if needed) the CGB/SGB flags. It is a good idea to pad the
93 image to a valid size as well (“valid” meaning a power of 2, times 32
94 KiB).
95 The following will make a plain, non-color Game Boy game without checking
97 for a valid size:
98 $ rgbfix -v foo.gb
100 The following will make a SGB-enabled, color-enabled game with a title of
102 “foobar”, and pad it to a valid size. (The Game Boy itself does not use
103 the title, but some emulators or ROM managers do.)
104 $ rgbfix -vcs -l 0x33 -p 255 -t foobar baz.gb
106 The following will duplicate the header (sans global checksum) of the
108 game “Survival Kids”:
109 $ rgbfix -cjsv -k A4 -l 0x33 -m 0x1B -p 0xFF -r 3 -t
111 SURVIVALKIDAVKE SurvivalKids.gbc
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114 Please report bugs on GitHub:
115 https://github.com/gbdev/rgbds/issues.
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118 rgbasm(1), rgblink(1), rgbds(7)
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121 rgbfix was originally released by Carsten Sørensen as a standalone pro‐
122 gram called gbfix, and was later packaged in RGBDS by Justin Lloyd. It
123 is now maintained by a number of contributors at .:
124 https://github.com/gbdev/rgbds
125BSD December 5, 2019 BSD