shithub: rgbds

ref: 46c131bc8651dedc981c9297ebea5e32bdbedeb7
dir: /src/rgbfix/main.c/

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/*
 * RGBFix : Perform various tasks on a Gameboy image-file
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "asmotor.h"

/*
 * Option defines
 *
 */

#define OPTF_DEBUG	0x01L
#define OPTF_PAD	0x02L
#define OPTF_VALIDATE	0x04L
#define OPTF_TITLE	0x08L
#define OPTF_TRUNCATE	0x10L

unsigned long ulOptions;

/*
 * Misc. variables
 *
 */

unsigned char NintendoChar[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,
};

/*
 * Misc. routines
 *
 */

void PrintUsage(void)
{
	printf("RGBFix v" RGBFIX_VERSION
		" (part of ASMotor " ASMOTOR_VERSION ")\n\n");

	printf("Usage: rgbfix [options] image[.gb]\n");
	printf("Options:\n");
	printf("\t-h\t\tThis text\n");
	printf("\t-d\t\tDebug: Don't change image\n");
	printf("\t-p\t\tPad image to valid size\n\t\t\tPads to 32/64/128/256/512kB as appropriate\n");
	printf("\t-r\t\ttRuncate image to valid size\n\t\t\tTruncates to 32/64/128/256/512kB as appropriate\n");
	printf("\t-t<name>\tChange cartridge title field (16 characters)\n");
	printf("\t-v\t\tValidate header\n\t\t\tCorrects - Nintendo Character Area (0x0104)\n\t\t\t\t - ROM type (0x0147)\n\t\t\t\t - ROM size (0x0148)\n\t\t\t\t - Checksums (0x014D-0x014F)\n");

	exit(0);
}

void FatalError(char *s)
{
	printf("\n***ERROR: %s\n\n", s);
	PrintUsage();
}

long int FileSize(FILE * f)
{
	long prevpos;
	long r;

	fflush(f);
	prevpos = ftell(f);
	fseek(f, 0, SEEK_END);
	r = ftell(f);
	fseek(f, prevpos, SEEK_SET);
	return (r);
}

int FileExists(char *s)
{
	FILE *f;

	if ((f = fopen(s, "rb")) != NULL) {
		fclose(f);
		return (1);
	} else
		return (0);
}

/*
 * Das main
 *
 */

int main(int argc, char *argv[])
{
	int argn = 1;
	char filename[512];
	char cartname[32];
	FILE *f;

	ulOptions = 0;

	if ((--argc) == 0)
		PrintUsage();

	while (*argv[argn] == '-') {
		argc -= 1;
		switch (argv[argn++][1]) {
		case '?':
		case 'h':
			PrintUsage();
			break;
		case 'd':
			ulOptions |= OPTF_DEBUG;
			break;
		case 'p':
			ulOptions |= OPTF_PAD;
			break;
		case 'r':
			ulOptions |= OPTF_TRUNCATE;
			break;
		case 'v':
			ulOptions |= OPTF_VALIDATE;
			break;
		case 't':
			strncpy(cartname, argv[argn - 1] + 2, 16);
			ulOptions |= OPTF_TITLE;
			break;
		}
	}

	strcpy(filename, argv[argn++]);

	if (!FileExists(filename))
		strcat(filename, ".gb");

	f = fopen(filename, "rb+");
	if (!f)
		FatalError("Unable to open file");

	/*
	 * -d (Debug) option code
	 *
	 */

	if (ulOptions & OPTF_DEBUG) {
		printf("-d (Debug) option enabled...\n");
	}

	/*
	 * -p (Pad) option code
	 *
	 */

	if (ulOptions & OPTF_PAD) {
		long size, padto;
		long bytesadded = 0;

		size = FileSize(f);
		padto = 0x8000L;
		while (size > padto)
			padto *= 2;

		printf("Padding to %ldkB:\n", padto / 1024);

		/*
		   if( padto<=0x80000L )
		   {
		   */
		if (size != padto) {
			fflush(stdout);

			fseek(f, 0, SEEK_END);
			while (size < padto) {
				size += 1;
				if ((ulOptions & OPTF_DEBUG) == 0)
					fputc(0, f);
				bytesadded += 1;
			}
			fflush(f);

			printf("\tAdded %ld bytes\n", bytesadded);
		} else
			printf("\tNo padding needed\n");
		/*
		   }
		   else
		   FatalError( "Image size exceeds 512kB" );
		   */
	}

	/*
	 * -r (Truncate) option code
	 *
	 */

	if (ulOptions & OPTF_TRUNCATE) {
		long size, padto;
		char tempfile[] = "/tmp/rgbfix-XXXXXX";
		FILE *tf;

		size = FileSize(f);
		padto = 256 * 32768;
		while (size < padto)
			padto /= 2;

		printf("Truncating to %ldkB:\n", padto / 1024);

		mkstemp(tempfile);

		if ((ulOptions & OPTF_DEBUG) == 0) {
			if ((tf = fopen(tempfile, "wb")) != NULL) {
				fseek(f, 0, SEEK_SET);
				while (padto--) {
					fputc(fgetc(f), tf);
				}
				fclose(f);
				fclose(tf);
				remove(filename);
				rename(tempfile, filename);
				f = fopen(filename, "rb+");
			}
		}
	}

	/*
	 * -t (Set carttitle) option code
	 *
	 */

	if (ulOptions & OPTF_TITLE) {
		printf("Setting cartridge title:\n");
		if ((ulOptions & OPTF_DEBUG) == 0) {
			fflush(f);
			fseek(f, 0x0134L, SEEK_SET);
			fwrite(cartname, 16, 1, f);
			fflush(f);
		}
		printf("\tTitle set to %s\n", cartname);
	}

	/*
	 * -v (Validate header) option code
	 *
	 */

	if (ulOptions & OPTF_VALIDATE) {
		long i, byteschanged = 0;
		long cartromsize, calcromsize = 0, filesize;
		long carttype;
		unsigned short cartchecksum = 0, calcchecksum = 0;
		unsigned char cartcompchecksum = 0, calccompchecksum =
			0;
		int ch;

		printf("Validating header:\n");
		fflush(stdout);

		/* Nintendo Character Area */

		fflush(f);
		fseek(f, 0x0104L, SEEK_SET);

		for (i = 0; i < 48; i += 1) {
			int ch;

			ch = fgetc(f);
			if (ch == EOF)
				ch = 0x00;
			if (ch != NintendoChar[i]) {
				byteschanged += 1;

				if ((ulOptions & OPTF_DEBUG) == 0) {
					fseek(f, -1, SEEK_CUR);
					fputc(NintendoChar[i], f);
					fflush(f);
				}
			}
		}

		fflush(f);

		if (byteschanged)
			printf
				("\tChanged %ld bytes in the Nintendo Character Area\n",
				 byteschanged);
		else
			printf("\tNintendo Character Area is OK\n");

		/* ROM size */

		fflush(f);
		fseek(f, 0x0148L, SEEK_SET);
		cartromsize = fgetc(f);
		if (cartromsize == EOF)
			cartromsize = 0x00;
		filesize = FileSize(f);
		while (filesize > (0x8000L << calcromsize))
			calcromsize += 1;

		if (calcromsize != cartromsize) {
			if ((ulOptions & OPTF_DEBUG) == 0) {
				fseek(f, -1, SEEK_CUR);
				fputc(calcromsize, f);
				fflush(f);
			}
			printf("\tChanged ROM size byte from 0x%02lX (%ldkB) to 0x%02lX (%ldkB)\n",
				 cartromsize,
				 (0x8000L << cartromsize) / 1024,
				 calcromsize,
				 (0x8000L << calcromsize) / 1024);
		} else
			printf("\tROM size byte is OK\n");

		/* Cartridge type */

		fflush(f);
		fseek(f, 0x0147L, SEEK_SET);
		carttype = fgetc(f);
		if (carttype == EOF)
			carttype = 0x00;

		if (FileSize(f) > 0x8000L) {
			/* carttype byte must != 0x00 */
			if (carttype == 0x00) {
				if ((ulOptions & OPTF_DEBUG) == 0) {
					fseek(f, -1, SEEK_CUR);
					fputc(0x01, f);
					fflush(f);
				}
				printf
					("\tCartridge type byte changed to 0x01\n");
			} else
				printf("\tCartridge type byte is OK\n");
		} else {
			/* carttype byte can be anything? */
			printf("\tCartridge type byte is OK\n");
		}

		/* Checksum */

		fflush(f);
		fseek(f, 0, SEEK_SET);

		for (i = 0; i < (0x8000L << calcromsize); i += 1) {
			ch = fgetc(f);
			if (ch == EOF)
				ch = 0;

			if (i < 0x0134L)
				calcchecksum += ch;
			else if (i < 0x014DL) {
				calccompchecksum += ch;
				calcchecksum += ch;
			} else if (i == 0x014DL)
				cartcompchecksum = ch;
			else if (i == 0x014EL)
				cartchecksum = ch << 8;
			else if (i == 0x014FL)
				cartchecksum |= ch;
			else
				calcchecksum += ch;
		}

		calccompchecksum = 0xE7 - calccompchecksum;
		calcchecksum += calccompchecksum;

		if (cartchecksum != calcchecksum) {
			fflush(f);
			fseek(f, 0x014EL, SEEK_SET);
			if ((ulOptions & OPTF_DEBUG) == 0) {
				fputc(calcchecksum >> 8, f);
				fputc(calcchecksum & 0xFF, f);
			}
			fflush(f);
			printf
				("\tChecksum changed from 0x%04lX to 0x%04lX\n",
				 (long)cartchecksum, (long)calcchecksum);
		} else
			printf("\tChecksum is OK\n");

		if (cartcompchecksum != calccompchecksum) {
			fflush(f);
			fseek(f, 0x014DL, SEEK_SET);
			if ((ulOptions & OPTF_DEBUG) == 0)
				fputc(calccompchecksum, f);
			fflush(f);
			printf
				("\tCompChecksum changed from 0x%02lX to 0x%02lX\n",
				 (long)cartcompchecksum,
				 (long)calccompchecksum);
		} else
			printf("\tCompChecksum is OK\n");

	}

	fclose(f);

	return (0);
}