ref: d2f52fdd0cb02c16be354bc04bc78bb2673ea582
parent: 05be8e00113ef07aabf8a5eeb1ef98cab6a8aaec
author: Anthony J. Bentley <[email protected]>
date: Wed Dec 22 08:48:44 EST 2010
Rewrite rgbfix from scratch, under a free ISC license. Slight changes in usage; the man page has been updated accordingly.
--- a/man/rgbfix.1
+++ b/man/rgbfix.1
@@ -7,9 +7,11 @@
.\" SECTION
.Sh SYNOPSIS
.Nm rgbfix
-.Op Fl Ccdjqrsv
+.Op Fl Ccjsv
.Op Fl k Ar licensee_str
+.Op Fl l Ar licensee_id
.Op Fl m Ar mbc_type
+.Op Fl n Ar rom_version
.Op Fl p Ar pad_value
.Op Fl r Ar ram_size
.Op Fl t Ar title_str
@@ -24,20 +26,19 @@
.Bl -tag -width Ds
.\" ITEM
.It Fl C
-Set the Game Boy Color compatible flag: [0x143] = 0x80.
-This flag and the
+Set the Game Boy Color\(enonly flag: [0x143] = 0xC0.
+If both this and the
.Fl c
-flag are mutually exclusive.
+flag are set, this takes precedence.
.\" ITEM
.It Fl c
-Set the Game Boy Color only flag: [0x143] = 0xC0.
-This flag and the
+Set the Game Boy Color\(encompatible flag: [0x143] = 0x80.
+If both this and the
.Fl C
-flag are mutually exclusive.
+flag are set,
+.Fl C
+takes precedence.
.\" ITEM
-.It Fl d
-Don't perform any changes, just pretend to for debugging.
-.\" ITEM
.It Fl j
Set the non-Japanese region flag: [0x14A] = 1.
.\" ITEM
@@ -45,9 +46,16 @@
Set the new licensee string ([0x144\(en0x145]) to a given string, truncated
to at most two characters.
.\" ITEM
+.It Fl l Ar licensee_id
+Set the old licensee code, [0x14B], to a given value from 0 to 0xFF.
+This value is deprecated and should be set to 0x33 in all new software.
+.\" ITEM
.It Fl m Ar mbc_type
Set the MBC type, [0x147], to a given value from 0 to 0xFF.
.\" ITEM
+.It Fl n Ar rom_version
+Set the ROM version, [0x14C], to a given value from 0 to 0xFF.
+.\" ITEM
.It Fl p Ar pad_value
Pad the image to a valid size with a given pad value from 0 to 0xFF.
.Nm
@@ -55,14 +63,11 @@
give a warning thereafter.
The cartridge size byte ([0x148]) will be changed to reflect this new size.
.\" ITEM
-.It Fl q
-Enable quiet mode, suppressing all text except errors.
-.\" ITEM
.It Fl r Ar ram_size
Set the RAM size, [0x149], to a given value from 0 to 0xFF.
.\" ITEM
.It Fl s
-Set the SGB flag: [0x146] = 3, and set the old licensee code: [0x14B] = 0x33.
+Set the SGB flag: [0x146] = 3.
.\" ITEM
.It Fl t Ar title
Set the title string ([0x134\(en0x143]) to a given string, truncated to at
@@ -97,12 +102,12 @@
(The Game Boy itself does not use the title, but some emulators or ROM managers
might.)
.Pp
-.D1 $ rgbfix \-vCs \-p 0 \-t foobar baz.gb
+.D1 $ rgbfix \-vcs \-p 0 \-t foobar baz.gb
.Pp
The following will duplicate the header (sans global checksum) of the game
"Survival Kids":
.Pp
-.D1 $ rgbfix \-Cjsv \-k A4 \-m 0x1B \-p 0xFF \-r 3 \-t SURVIVALKIDAVKE SurvivalKids.gbc
+.D1 $ rgbfix \-cjsv \-k A4 \-m 0x1B \-p 0xFF \-r 3 \-t SURVIVALKIDAVKE SurvivalKids.gbc
.\" SECTION
.Sh SEE ALSO
.Xr rgbds 7 ,
--- a/src/fix/main.c
+++ b/src/fix/main.c
@@ -15,18 +15,402 @@
*/
#include <err.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdint.h>
#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+static void
+usage(void)
+{+ printf("usage: rgbfix [-Ccjsv] [-k licensee_str] [-l licensee_id] "+ "[-m mbc_type]\n" " [-n rom_version] [-p pad_value] "
+ "[-r ram_size] [-t title_str] file.gb\n");
+}
+
int
main(int argc, char *argv[])
{FILE *rom;
+ int ch;
+ char *ep;
+ /*
+ * Open the ROM file
+ */
+
if (argc < 2)
- errx(1, "Usage: rgbfix romfile");
+ usage();
if ((rom = fopen(argv[argc - 1], "rb+")) == NULL)
err(1, "Error opening file %s", argv[argc - 1]);
+
+ /*
+ * Parse command-line options
+ */
+
+ /* all flags default to false unless options specify otherwise */
+ bool validate = false;
+ bool settitle = false;
+ bool colorcompatible = false;
+ bool coloronly = false;
+ bool nonjapan = false;
+ bool setlicensee = false;
+ bool setnewlicensee = false;
+ bool super = false;
+ bool setcartridge = false;
+ bool setramsize = false;
+ bool resize = false;
+ bool setversion = false;
+
+ char *title = NULL; /* game title in ASCII */
+ char *newlicensee = NULL; /* new licensee ID, two ASCII characters */
+
+ int licensee = -1; /* old licensee ID */
+ int cartridge = -1; /* cartridge hardware ID */
+ int ramsize = -1; /* RAM size ID */
+ int version = -1; /* mask ROM version number */
+ int padvalue = -1; /* to pad the rom with if it changes size */
+
+ while ((ch = getopt(argc, argv, "Ccjk:l:m:n:p:sr:t:v")) != -1) {+ switch (ch) {+ case 'C':
+ coloronly = true;
+ /* FALLTHROUGH */
+ case 'c':
+ colorcompatible = true;
+ break;
+ case 'j':
+ nonjapan = true;
+ break;
+ case 'k':
+ setnewlicensee = true;
+
+ if (strlen(optarg) != 2)
+ errx(1, "New licensee code %s is not the "
+ "correct length of 2 characters", optarg);
+
+ newlicensee = optarg;
+ break;
+ case 'l':
+ setlicensee = true;
+
+ licensee = strtoul(optarg, &ep, 0);
+ if (optarg[0] == '\0' || *ep != '\0')
+ errx(1, "Invalid argument for option 'l'");
+ if (licensee < 0 || licensee > 0xFF)
+ errx(1, "Argument for option 'l' must be "
+ "between 0 and 255");
+ break;
+ case 'm':
+ setcartridge = true;
+
+ cartridge = strtoul(optarg, &ep, 0);
+ if (optarg[0] == '\0' || *ep != '\0')
+ errx(1, "Invalid argument for option 'm'");
+ if (cartridge < 0 || cartridge > 0xFF)
+ errx(1, "Argument for option 'm' must be "
+ "between 0 and 255");
+ break;
+ case 'n':
+ setversion = true;
+
+ version = strtoul(optarg, &ep, 0);
+ if (optarg[0] == '\0' || *ep != '\0')
+ errx(1, "Invalid argument for option 'n'");
+ if (version < 0 || version > 0xFF)
+ errx(1, "Argument for option 'n' must be "
+ "between 0 and 255");
+ break;
+ case 'p':
+ resize = true;
+
+ padvalue = strtoul(optarg, &ep, 0);
+ if (optarg[0] == '\0' || *ep != '\0')
+ errx(1, "Invalid argument for option 'p'");
+ if (padvalue < 0 || padvalue > 0xFF)
+ errx(1, "Argument for option 'p' must be "
+ "between 0 and 255");
+ break;
+ case 'r':
+ setramsize = true;
+
+ ramsize = strtoul(optarg, &ep, 0);
+ if (optarg[0] == '\0' || *ep != '\0')
+ errx(1, "Invalid argument for option 'r'");
+ if (ramsize < 0 || ramsize > 0xFF)
+ errx(1, "Argument for option 'r' must be "
+ "between 0 and 255");
+ break;
+ case 's':
+ super = true;
+ break;
+ case 't':
+ settitle = true;
+
+ if (strlen(optarg) > 16)
+ errx(1, "Title %s is greater than the "
+ "maximum of 16 characters", optarg);
+
+ if (strlen(optarg) == 16)
+ warnx("Title %s is 16 chars, it is best "+ "to keep it to 15 or fewer", optarg);
+
+ title = optarg;
+ break;
+ case 'v':
+ validate = true;
+ break;
+ default:
+ usage();
+ /* NOTREACHED */
+ }
+ }
+ argc -= optind;
+ argv += optind;
+
+ /*
+ * Write changes to ROM
+ */
+
+ if (validate) {+ /*
+ * Offset 0x104–0x133: Nintendo Logo
+ * This is a bitmap image that displays when the Game Boy is
+ * turned on. It must be intact, or the game will not boot.
+ */
+
+ /*
+ * See also: global checksums at 0x14D–0x14F, They must
+ * also be correct for the game to boot, so we fix them
+ * as well when the -v flag is set.
+ */
+
+ uint8_t ninlogo[48] = {+ 0xCE, 0xED, 0x66, 0x66, 0xCC, 0x0D, 0x00, 0x0B,
+ 0x03, 0x73, 0x00, 0x83, 0x00, 0x0C, 0x00, 0x0D,
+ 0x00, 0x08, 0x11, 0x1F, 0x88, 0x89, 0x00, 0x0E,
+ 0xDC, 0xCC, 0x6E, 0xE6, 0xDD, 0xDD, 0xD9, 0x99,
+ 0xBB, 0xBB, 0x67, 0x63, 0x6E, 0x0E, 0xEC, 0xCC,
+ 0xDD, 0xDC, 0x99, 0x9F, 0xBB, 0xB9, 0x33, 0x3E
+ };
+
+ fseek(rom, 0x104, SEEK_SET);
+ fwrite(ninlogo, 1, 48, rom);
+ }
+
+ if (settitle) {+ /*
+ * Offset 0x134–0x143: Game Title
+ * This is a sixteen-character game title in ASCII (no high-
+ * bit characters).
+ */
+
+ /*
+ * See also: CGB flag at 0x143. The sixteenth character of
+ * the title is co-opted for use as the CGB flag, so they
+ * may conflict.
+ */
+
+ fseek(rom, 0x134, SEEK_SET);
+ fwrite(title, 1, strlen(title) + 1, rom);
+
+ while (ftell(rom) < 0x143)
+ fputc(0, rom);
+ }
+
+ if (colorcompatible) {+ /*
+ * Offset 0x143: Game Boy Color Flag
+ * If bit 7 is set, the ROM has Game Boy Color features.
+ * If bit 6 is also set, the ROM is for the Game Boy Color
+ * only. (However, this is not actually enforced by the
+ * Game Boy.)
+ */
+
+ /*
+ * See also: Game Title at 0x134–0x143. The sixteenth
+ * character of the title overlaps with this flag, so they
+ * may conflict.
+ */
+
+ uint8_t byte;
+
+ fseek(rom, 0x143, SEEK_SET);
+ byte = fgetc(rom);
+
+ byte |= 1 << 7;
+ if (coloronly)
+ byte |= 1 << 6;
+
+ if (byte & 0x3F)
+ warnx("Color flag conflicts with game title");+
+ fseek(rom, 0x143, SEEK_SET);
+ fputc(byte, rom);
+ }
+
+ if (setnewlicensee) {+ /*
+ * Offset 0x144–0x145: New Licensee Code
+ * This is a two-character code identifying which company
+ * created the game.
+ */
+
+ /*
+ * See also: the original Licensee ID at 0x14B.
+ * This is deprecated and in all newer games is used instead
+ * as a Super Game Boy flag.
+ */
+
+ fseek(rom, 0x144, SEEK_SET);
+ fwrite(newlicensee, 1, 2, rom);
+ }
+
+ if (super) {+ /*
+ * Offset 0x146: Super Game Boy Flag
+ * If not equal to 3, Super Game Boy functions will be
+ * disabled.
+ */
+
+ /*
+ * See also: the original Licensee ID at 0x14B.
+ * If the Licensee code is not equal to 0x33, Super Game Boy
+ * functions will be disabled.
+ */
+
+ if (!setlicensee)
+ warnx("You should probably set both '-s' and "+ "'-l 0x33'");
+
+ fseek(rom, 0x146, SEEK_SET);
+ fputc(3, rom);
+ }
+
+ if (setcartridge) {+ /*
+ * Offset 0x147: Cartridge Type
+ * Identifies whether the ROM uses a memory bank controller,
+ * external RAM, timer, rumble, or battery.
+ */
+
+ fseek(rom, 0x147, SEEK_SET);
+ fputc(cartridge, rom);
+ }
+
+ if (resize) {+ /*
+ * Offset 0x148: Cartridge Size
+ * Identifies the size of the cartridge ROM.
+ */
+
+ /* We will pad the ROM to match the size given in the header. */
+ int romsize, newsize, headbyte;
+ fseek(rom, 0, SEEK_END);
+ romsize = ftell(rom);
+ newsize = 0x8000;
+
+ headbyte = 0;
+ while (romsize > newsize) {+ newsize <<= 1;
+ headbyte++;
+ }
+
+ while (newsize != ftell(rom)) /* ROM needs resizing */
+ fputc(padvalue, rom);
+
+ if (newsize > 0x800000) /* ROM is bigger than 8MiB */
+ warnx("ROM size is bigger than 8MiB");+
+ fseek(rom, 0x148, SEEK_SET);
+ fputc(headbyte, rom);
+ }
+
+ if (setramsize) {+ /*
+ * Offset 0x149: RAM Size
+ */
+
+ fseek(rom, 0x149, SEEK_SET);
+ fputc(ramsize, rom);
+ }
+
+ if (nonjapan) {+ /*
+ * Offset 0x14A: Non-Japanese Region Flag
+ */
+
+ fseek(rom, 0x14A, SEEK_SET);
+ fputc(1, rom);
+ }
+
+ if (setlicensee) {+ /*
+ * Offset 0x14B: Licensee Code
+ * This identifies which company created the game.
+ *
+ * This byte is deprecated and should be set to 0x33 in new
+ * releases.
+ */
+
+ /*
+ * See also: the New Licensee ID at 0x144–0x145.
+ */
+
+ fseek(rom, 0x14B, SEEK_SET);
+ fputc(licensee, rom);
+ }
+
+ if (setversion) {+ /*
+ * Offset 0x14C: Mask ROM Version Number
+ * Which version of the ROM this is.
+ */
+
+ fseek(rom, 0x14C, SEEK_SET);
+ fputc(version, rom);
+ }
+
+ if (validate) {+ /*
+ * Offset 0x14D: Header Checksum
+ */
+
+ uint8_t headcksum;
+
+ headcksum = 0;
+ fseek(rom, 0x134, SEEK_SET);
+ for (int i = 0; i < (0x14D - 0x134); ++i)
+ headcksum = headcksum - fgetc(rom) - 1;
+
+ fseek(rom, 0x14D, SEEK_SET);
+ fputc(headcksum, rom);
+
+ /*
+ * Offset 0x14E–0x14F: Global Checksum
+ */
+
+ uint16_t globalcksum;
+
+ globalcksum = 0;
+
+ rewind(rom);
+ for (int i = 0; i < 0x14E; ++i)
+ globalcksum += fgetc(rom);
+
+ int byte;
+ fseek(rom, 0x150, SEEK_SET);
+ while ((byte = fgetc(rom)) != EOF)
+ globalcksum += byte;
+
+ fseek(rom, 0x14E, SEEK_SET);
+ fputc(globalcksum >> 8, rom);
+ fputc(globalcksum & 0xFF, rom);
+ }
fclose(rom);