tool to create saturn boot sector

1 files changed, 218 insertions, 0 deletions

diff --git a/src/satmkboot.c b/src/satmkboot.c
new file mode 100644
index 0000000..6bd9823
--- /dev/null
+++ b/src/satmkboot.c
@@ -0,0 +1,218 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+
+#include "bootinfo.h"
+#include "symbols.h"
+
+static struct systemid sysid = {
+	.title        = "TEST TITLE                                                                                                      ",
+	.maker        = "SEGA TP T-000   ",
+	.product      = "T-000000G ",
+	.version      = "V0.001",
+	.reldate      = "20000101",
+	.device       = "CD-1/1  ",
+	.regions      = "JTUBKAEL  ",
+	.peripherals  = "J               ",
+	.bootsize     = 0xe00,
+	.stack_master = 0,
+	.stack_slave  = 0,
+	.load_addr    = 0x06004000,
+	.load_size    = 0,
+};
+
+static char ipbuf[0x7200];
+static char *ipfile, *outfile;
+
+static char *serialize_region_code(char *out, const struct symbolname *region)
+{
+	size_t namelen  = strlen(region->name);
+	char  *tmp = out;
+	char  *end = out+32;
+
+	memcpy(tmp, "\xa0\x0e\x00\x09For ", 8); tmp += 8;
+	memcpy(tmp, region->name,     namelen); tmp += namelen;
+	*tmp++ = '.';
+	memset(tmp, ' ', end - tmp);
+	return end;
+}
+
+#define WRITE(f,p,s) fwrite(p,s,1,f)
+#define WRITE32(f,v) fwrite((char[]){(v)>>24,(v)>>16,(v)>>8,(v)},4,1,f)
+
+static int write_output(FILE *fp)
+{
+	static const unsigned char zeros[16];
+	extern const unsigned char securitycode[];
+	extern const size_t        securitycode_size;
+
+	/* system id - 0x100 bytes */
+	WRITE  (fp, "SEGA SEGASATURN ", 16);
+	WRITE  (fp, sysid.maker,        16);
+	WRITE  (fp, sysid.product,      10);
+	WRITE  (fp, sysid.version,       6);
+	WRITE  (fp, sysid.reldate,       8);
+	WRITE  (fp, sysid.device,        8);
+	WRITE  (fp, sysid.regions,      10);
+	WRITE  (fp, "      ",            6);
+	WRITE  (fp, sysid.peripherals,  16);
+	WRITE  (fp, sysid.title,       112);
+	WRITE  (fp, zeros,              16); /* reserved bytes */
+	WRITE32(fp, sysid.bootsize);
+	WRITE  (fp, zeros,               4); /* reserved bytes */
+	WRITE32(fp, sysid.stack_master);
+	WRITE32(fp, sysid.stack_slave);
+	WRITE32(fp, sysid.load_addr);
+	WRITE32(fp, sysid.load_size);
+	WRITE  (fp, zeros,               8); /* reserved bytes */
+
+	/* security code */
+	WRITE(fp, securitycode, securitycode_size);
+
+	/* initial program */
+	WRITE(fp, ipbuf, sysid.bootsize - 0xe00);
+	return ferror(fp) ? -1 : 0;
+}
+
+static size_t load_ip(char *filename, char *out, size_t maxsize)
+{
+	FILE  *fp;
+	size_t size;
+	const char *errprefix = "Error loading initial program";
+
+	if (!(fp = fopen(filename, "rb"))) {
+		goto fail_perror;
+	}
+	if ((size = fread(out, 1, maxsize, fp)) < maxsize) {
+		/* read fewer than requested amount. determine if we hit error or eof */
+		if (ferror(fp)) {
+			goto fail_perror;
+		}
+	} else {
+		/* successfully read the requested amount. verify we reached eof */
+		if (fgetc(fp) != EOF) {
+			fprintf(stderr, "%s: exceeds maximum size\n", errprefix);
+			goto fail;
+		}
+	}
+
+	fclose(fp);
+	return size;
+
+fail_perror:
+	perror(errprefix);
+fail:
+	if (fp) fclose(fp);
+	return -1;
+}
+
+static void usage(const char *progname)
+{
+	const int width = 20;
+
+	fprintf(stderr, "usage: %s -h\n",      progname);
+	fprintf(stderr, "       %s -io\n\n",   progname);
+	fprintf(stderr, "\t%-*s%s\n", width, "-h",              "Show this help text");
+	fprintf(stderr, "\t%-*s%s\n", width, "-i ip.bin",       "Initial program code file");
+	fprintf(stderr, "\t%-*s%s\n", width, "-o output",       "Output file");
+}
+
+static int process_args(int argc, char **argv)
+{
+	int fail = 0, help = 0;
+	int opt;
+
+	extern char *optarg;
+	extern int optind, optopt;
+
+	while ((opt = getopt(argc, argv, ":hi:o:")) != -1) {
+		switch (opt) {
+		case 'h':
+			help = 1;
+			break;
+
+		case 'i':
+			if (ipfile) {
+				fprintf(stderr, "Duplicate -i parameter\n");
+				fail = 1;
+			}
+			ipfile = optarg;
+			break;
+
+		case 'o':
+			if (outfile) {
+				fprintf(stderr, "Duplicate -o parameter\n");
+				fail = 1;
+			}
+			outfile = optarg;
+			break;
+
+		case ':':
+			fprintf(stderr, "Option '%c' missing required parameter\n", optopt);
+			fail = 1;
+			break;
+
+		default:
+			fprintf(stderr, "Unknown option '%c'\n", opt);
+			fail = 1;
+		}
+	}
+
+	if (help) {
+		usage(argv[0]);
+	} else {
+		if (argv[optind]) {
+			fprintf(stderr, "Unknown extra arguments\n");
+			fail = 1;
+		}
+		if (!ipfile || !outfile) {
+			fprintf(stderr, "Missing required option\n");
+			fail = 1;
+		}
+
+		if (fail) {
+			fprintf(stderr, "Use -h option for help on correct usage.\n");
+		}
+	}
+
+	return fail | help;
+}
+
+int main(int argc, char **argv)
+{
+	FILE  *outfp = NULL;
+	char  *ipout = ipbuf;
+	size_t ipsize;
+
+	if (process_args(argc, argv)) {
+		return 1;
+	}
+
+	for (int i = 0; i < 10 && sysid.regions[i] != ' '; i++) {
+		const struct symbolname *region = find_symbol(regiondefs, sysid.regions[i]);
+		if (region) ipout = serialize_region_code(ipout, region);
+	}
+
+	if ((ipsize = load_ip(ipfile, ipout, sizeof ipbuf - (ipout - ipbuf))) == -1) {
+		goto fail;
+	}
+	sysid.bootsize += ipsize;
+
+	if (!(outfp = fopen(outfile, "wb"))) {
+		perror("Error opening output file");
+		goto fail;
+	}
+
+	if (write_output(outfp)) {
+		perror("Error writing output");
+		goto fail;
+	}
+
+	fclose(outfp);
+	return 0;
+
+fail:
+	if (outfp) fclose(outfp);
+	return 1;
+}