Swizzle extraction toolkit

swizzle.c

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <unistd.h>
#include <sys/fcntl.h>
#include <sys/stat.h>

int check(uint8_t *);
void print(uint8_t *);

int
main(int argv, char **argc)
{
	int fd = open("bios.rom", O_RDONLY);
	if (fd < 0)
		return 1;

	struct stat st;
	if (fstat(fd, &st) < 0)
		return 2;

	uint8_t *buf = malloc(st.st_size);
	if (buf == NULL)
		return 3;

	if (read(fd, buf, st.st_size) != st.st_size)
		return 4;

	for (int off = 0; off < st.st_size - 32; off++)
		if (check(buf+off)) {
			printf("match at offset 0x%x:\n", off);
			print(buf+off);
		}

	return 0;
}

int
check(uint8_t *buf)
{
	uint32_t bits = 0;

	for (int i = 0; i < 32; i++)
		bits |= (1ULL << buf[i]);

	if (bits == 0xffffffff)
		return 1;

	return 0;
}

void
print(uint8_t *buf)
{
	for (int i = 0; i < 4; i++) {
		for (int j = 0; j < 8; j++)
			printf("0x%02x, ", buf[i*8+j]);
		printf("\n");
	}
}