ref: 1f2f797cb9967645f5a5714431eebacf5d289edf
dir: /src/fix/main.c/
/* * This file is part of RGBDS. * * Copyright (c) 2010-2018, Anthony J. Bentley and RGBDS contributors. * * SPDX-License-Identifier: MIT */ #include <stdbool.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include "extern/err.h" #include "extern/getopt.h" #include "version.h" /* Short options */ static char const *optstring = "Ccf:i:jk:l:m:n:p:r:st:Vv"; /* * Equivalent long options * Please keep in the same order as short opts * * Also, make sure long opts don't create ambiguity: * A long opt's name should start with the same letter as its short opt, * except if it doesn't create any ambiguity (`verbose` versus `version`). * This is because long opt matching, even to a single char, is prioritized * over short opt matching */ static struct option const longopts[] = { { "color-only", no_argument, NULL, 'C' }, { "color-compatible", no_argument, NULL, 'c' }, { "fix-spec", required_argument, NULL, 'f' }, { "game-id", required_argument, NULL, 'i' }, { "non-japanese", no_argument, NULL, 'j' }, { "new-licensee", required_argument, NULL, 'k' }, { "old-licensee", required_argument, NULL, 'l' }, { "mbc-type", required_argument, NULL, 'm' }, { "rom-version", required_argument, NULL, 'n' }, { "pad-value", required_argument, NULL, 'p' }, { "ram-size", required_argument, NULL, 'r' }, { "sgb-compatible", no_argument, NULL, 's' }, { "title", required_argument, NULL, 't' }, { "version", no_argument, NULL, 'V' }, { "validate", no_argument, NULL, 'v' }, { NULL, no_argument, NULL, 0 } }; static void print_usage(void) { fputs( "Usage: rgbfix [-jsVv] [-C | -c] [-f <fix_spec>] [-i <game_id>] [-k <licensee>]\n" " [-l <licensee_byte>] [-m <mbc_type>] [-n <rom_version>]\n" " [-p <pad_value>] [-r <ram_size>] [-t <title_str>] <file>\n" "Useful options:\n" " -m, --mbc-type <value> set the MBC type byte to this value; refer\n" " to the man page for a list of values\n" " -p, --pad-value <value> pad to the next valid size using this value\n" " -r, --ram-size <code> set the cart RAM size byte to this value\n" " -V, --version print RGBFIX version and exit\n" " -v, --validate fix the header logo and both checksums (-f lhg)\n" "\n" "For help, use `man rgbfix' or go to https://rednex.github.io/rgbds/\n", stderr); exit(1); } int main(int argc, char *argv[]) { FILE *rom; int ch; char *ep; /* * Parse command-line options */ /* all flags default to false unless options specify otherwise */ bool fixlogo = false; bool fixheadsum = false; bool fixglobalsum = false; bool trashlogo = false; bool trashheadsum = false; bool trashglobalsum = false; bool settitle = false; bool setid = 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; /* game title in ASCII */ char *id; /* game ID in ASCII */ char *newlicensee; /* new licensee ID, two ASCII characters */ int licensee = 0; /* old licensee ID */ int cartridge = 0; /* cartridge hardware ID */ int ramsize = 0; /* RAM size ID */ int version = 0; /* mask ROM version number */ int padvalue = 0; /* to pad the rom with if it changes size */ while ((ch = musl_getopt_long_only(argc, argv, optstring, longopts, NULL)) != -1) { switch (ch) { case 'C': coloronly = true; /* FALLTHROUGH */ case 'c': colorcompatible = true; break; case 'f': fixlogo = strchr(optarg, 'l'); fixheadsum = strchr(optarg, 'h'); fixglobalsum = strchr(optarg, 'g'); trashlogo = strchr(optarg, 'L'); trashheadsum = strchr(optarg, 'H'); trashglobalsum = strchr(optarg, 'G'); break; case 'i': setid = true; if (strlen(optarg) != 4) errx(1, "Game ID %s must be exactly 4 characters", optarg); id = optarg; 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': printf("rgbfix %s\n", get_package_version_string()); exit(0); case 'v': fixlogo = true; fixheadsum = true; fixglobalsum = true; break; default: print_usage(); /* NOTREACHED */ } } argc -= optind; argv += optind; if (argc == 0) { fputs("FATAL: no input files\n", stderr); print_usage(); } /* * Open the ROM file */ rom = fopen(argv[argc - 1], "rb+"); if (rom == NULL) err(1, "Error opening file %s", argv[argc - 1]); /* * Read ROM header * * Offsets in the buffer are 0x100 less than the equivalent in ROM. */ uint8_t header[0x50]; if (fseek(rom, 0x100, SEEK_SET) != 0) err(1, "Could not locate ROM header"); if (fread(header, sizeof(uint8_t), sizeof(header), rom) != sizeof(header)) err(1, "Could not read ROM header"); if (fixlogo || trashlogo) { /* * 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 requested with the -f flag. */ 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 }; if (trashlogo) { for (int i = 0; i < sizeof(ninlogo); i++) ninlogo[i] = ~ninlogo[i]; } memcpy(header + 0x04, ninlogo, sizeof(ninlogo)); } 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. */ /* * See also: Game ID at 0x13F–0x142. These four ASCII * characters may conflict with the title. */ strncpy((char *)header + 0x34, title, 16); } if (setid) { /* * Offset 0x13F–0x142: Game ID * This is a four-character game ID in ASCII (no high-bit * characters). */ memcpy(header + 0x3F, id, 4); } 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. */ header[0x43] |= 1 << 7; if (coloronly) header[0x43] |= 1 << 6; if (header[0x43] & 0x3F) warnx("Color flag conflicts with game title"); } 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. */ header[0x44] = newlicensee[0]; header[0x45] = newlicensee[1]; } 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'"); header[0x46] = 3; } if (setcartridge) { /* * Offset 0x147: Cartridge Type * Identifies whether the ROM uses a memory bank controller, * external RAM, timer, rumble, or battery. */ header[0x47] = cartridge; } 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. */ long romsize, newsize; int headbyte; uint8_t *buf; if (fseek(rom, 0, SEEK_END) != 0) err(1, "Could not pad ROM file"); romsize = ftell(rom); if (romsize == -1) err(1, "Could not pad ROM file"); newsize = 0x8000; headbyte = 0; while (romsize > newsize) { newsize <<= 1; headbyte++; } if (newsize > 0x800000) /* ROM is bigger than 8MiB */ warnx("ROM size is bigger than 8MiB"); buf = malloc(newsize - romsize); if (buf == NULL) errx(1, "Couldn't allocate memory for padded ROM."); memset(buf, padvalue, newsize - romsize); if (fwrite(buf, 1, newsize - romsize, rom) != newsize - romsize) err(1, "Could not pad ROM file"); header[0x48] = headbyte; free(buf); } if (setramsize) { /* * Offset 0x149: RAM Size */ header[0x49] = ramsize; } if (nonjapan) { /* * Offset 0x14A: Non-Japanese Region Flag */ header[0x4A] = 1; } 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. */ header[0x4B] = licensee; } if (setversion) { /* * Offset 0x14C: Mask ROM Version Number * Which version of the ROM this is. */ header[0x4C] = version; } if (fixheadsum || trashheadsum) { /* * Offset 0x14D: Header Checksum */ uint8_t headcksum = 0; for (int i = 0x34; i < 0x4D; ++i) headcksum = headcksum - header[i] - 1; if (trashheadsum) headcksum = ~headcksum; header[0x4D] = headcksum; } /* * Before calculating the global checksum, we must write the modified * header to the ROM. */ if (fseek(rom, 0x100, SEEK_SET) != 0) err(1, "Could not locate header for writing"); if (fwrite(header, sizeof(uint8_t), sizeof(header), rom) != sizeof(header)) err(1, "Could not write modified ROM header"); if (fixglobalsum || trashglobalsum) { /* * Offset 0x14E–0x14F: Global Checksum */ uint16_t globalcksum = 0; if (fseek(rom, 0, SEEK_SET) != 0) err(1, "Could not start calculating global checksum"); int i = 0; int byte; while ((byte = fgetc(rom)) != EOF) { if (i != 0x14E && i != 0x14F) globalcksum += byte; i++; } if (ferror(rom)) err(1, "Could not calculate global checksum"); if (trashglobalsum) globalcksum = ~globalcksum; fseek(rom, 0x14E, SEEK_SET); fputc(globalcksum >> 8, rom); fputc(globalcksum & 0xFF, rom); if (ferror(rom)) err(1, "Could not write global checksum"); } if (fclose(rom) != 0) err(1, "Could not complete ROM write"); return 0; }