mirror of
https://github.com/notwa/mm
synced 2024-11-05 05:49:02 -08:00
227 lines
4.7 KiB
C
227 lines
4.7 KiB
C
// Based on uCON64's N64 checksum algorithm by Andreas Sterbenz
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <stdint.h>
|
|
|
|
typedef uint32_t u32;
|
|
typedef uint8_t u8;
|
|
|
|
static const u32
|
|
CRC_SEEDS[] = {
|
|
0,
|
|
0xF8CA4DDC, // 6101
|
|
0xF8CA4DDC, // 6102
|
|
0xA3886759, // 6103
|
|
0,
|
|
0xDF26F436, // 6105
|
|
0x1FEA617A, // 6106
|
|
0xF8CA4DDC, // iQue 1
|
|
0xF8CA4DDC, // iQue 2
|
|
0xF8CA4DDC // iQue 3
|
|
};
|
|
|
|
const static u32
|
|
BOOTCODE_CRCS[] = {
|
|
0,
|
|
0x6170A4A1, // 6101
|
|
0x90BB6CB5, // 6102
|
|
0x0B050EE0, // 6103
|
|
0,
|
|
0x98BC2C86, // 6105
|
|
0xACC8580A, // 6106
|
|
0xCD19FEF1, // iQue 1
|
|
0xB98CED9A, // iQue 2
|
|
0xE71C2766 // iQue 3
|
|
};
|
|
|
|
#define N_CRC (sizeof(CRC_SEEDS) / sizeof(CRC_SEEDS[0]))
|
|
|
|
// crc32 code via https://gist.github.com/notwa/5689243
|
|
// in turn via http://www.geocities.ws/malbrain/crc_c.html
|
|
|
|
static const u32
|
|
crc32_tbl[] = {
|
|
0x00000000, 0x1DB71064, 0x3B6E20C8, 0x26D930AC,
|
|
0x76DC4190, 0x6B6B51F4, 0x4DB26158, 0x5005713C,
|
|
0xEDB88320, 0xF00F9344, 0xD6D6A3E8, 0xCB61B38C,
|
|
0x9B64C2B0, 0x86D3D2D4, 0xA00AE278, 0xBDBDF21C
|
|
};
|
|
|
|
static inline u32
|
|
calc_crc32(u8 *ptr, int cnt, u32 crc) {
|
|
while (cnt--) {
|
|
crc = (crc >> 4) ^ crc32_tbl[(crc & 0xF) ^ (*ptr & 0xF)];
|
|
crc = (crc >> 4) ^ crc32_tbl[(crc & 0xF) ^ (*(ptr++) >> 4)];
|
|
}
|
|
return crc;
|
|
}
|
|
|
|
static inline u32
|
|
ROL(u32 i, u32 b) {
|
|
return (i << b) | (i >> (32 - b));
|
|
}
|
|
|
|
static inline u32
|
|
R4(u8 *b) {
|
|
return 0x1000000 * b[0] + 0x10000 * b[1] + 0x100 * b[2] + b[3];
|
|
}
|
|
|
|
static inline u8*
|
|
W4(u8 *b, u32 x) {
|
|
b[0] = (x >> 24) & 0xFF;
|
|
b[1] = (x >> 16) & 0xFF;
|
|
b[2] = (x >> 8) & 0xFF;
|
|
b[3] = (x >> 0) & 0xFF;
|
|
return b;
|
|
}
|
|
|
|
typedef struct {
|
|
u32 crc1;
|
|
u32 crc2;
|
|
} calc_crc_ret;
|
|
|
|
static inline calc_crc_ret
|
|
calc_crc(u8 *data, int bootcode, u8 *lookup) {
|
|
calc_crc_ret ret = {};
|
|
|
|
u32 seed = CRC_SEEDS[bootcode];
|
|
u32 t1 = seed;
|
|
u32 t2 = seed;
|
|
u32 t3 = seed;
|
|
u32 t4 = seed;
|
|
u32 t5 = seed;
|
|
u32 t6 = seed;
|
|
|
|
for (size_t i = 0x1000; i < 0x101000; i += 4) {
|
|
u32 d = R4(data + i);
|
|
|
|
if (t6 + d < t6) {
|
|
t4++;
|
|
}
|
|
|
|
t6 += d;
|
|
|
|
t3 ^= d;
|
|
|
|
u32 r = ROL(d, d & 0x1F);
|
|
|
|
t5 += r;
|
|
|
|
if (t2 > d) {
|
|
t2 ^= r;
|
|
} else {
|
|
t2 ^= t6 ^ d;
|
|
}
|
|
|
|
if (bootcode == 5) {
|
|
u32 o = i & 0xFF;
|
|
t1 += R4(lookup + o) ^ d;
|
|
} else {
|
|
t1 += t5;
|
|
}
|
|
}
|
|
|
|
if (bootcode == 3) {
|
|
ret.crc1 = (t6 ^ t4) + t3;
|
|
ret.crc2 = (t5 ^ t2) + t1;
|
|
} else if (bootcode == 6) {
|
|
ret.crc1 = t6 * t4 + t3;
|
|
ret.crc2 = t5 * t2 + t1;
|
|
} else {
|
|
ret.crc1 = t6 ^ t4 ^ t3;
|
|
ret.crc2 = t5 ^ t2 ^ t1;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
crc_version(u8 *buf) {
|
|
// returns negative on error
|
|
// otherwise returns version index
|
|
u32 bootsum = ~calc_crc32(buf + 0x40, 0x1000 - 0x40, ~0);
|
|
|
|
if (bootsum == 0) {
|
|
return -1;
|
|
}
|
|
|
|
for (int i = 0; i < N_CRC; i++) {
|
|
if (bootsum == BOOTCODE_CRCS[i]) {
|
|
return i;
|
|
}
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
static int
|
|
fix_crc(u8 *buf) {
|
|
// returns negative on error
|
|
// otherwise returns version index
|
|
// and modifies the buffer
|
|
int bootcode = crc_version(buf);
|
|
if (bootcode < 0) {
|
|
return bootcode;
|
|
}
|
|
|
|
calc_crc_ret crcs = calc_crc(buf, bootcode, buf + 0x750);
|
|
W4(buf + 0x10, crcs.crc1);
|
|
W4(buf + 0x14, crcs.crc2);
|
|
|
|
return bootcode;
|
|
}
|
|
|
|
int
|
|
main(int argc, char *argv[]) {
|
|
// TODO: add stdin/stdout mode
|
|
for (int i = 1; i < argc; i++) {
|
|
FILE *f = fopen(argv[i], "rb");
|
|
if (f == NULL) {
|
|
perror(argv[1]);
|
|
return 1;
|
|
}
|
|
|
|
fseek(f, 0, SEEK_END);
|
|
size_t size = ftell(f);
|
|
fseek(f, 0, SEEK_SET);
|
|
|
|
if (size < 0x00101000 || size > 0x10000000) {
|
|
fprintf(stderr, "Expected reasonable ROM size, got 0x%08X\n", (u32) size);
|
|
fclose(f);
|
|
return 2;
|
|
}
|
|
|
|
u8 *buf = malloc(size);
|
|
fread(buf, 1, size, f);
|
|
fclose(f);
|
|
|
|
int bootcode = fix_crc(buf);
|
|
if (bootcode < 0) {
|
|
//fprintf(stderr, "Failed to fix CRC. Error %i\n", bootcode);
|
|
fprintf(stderr, "Failed to fix CRC: unknown bootcode\n");
|
|
free(buf);
|
|
return bootcode;
|
|
}
|
|
|
|
f = fopen(argv[i], "wb");
|
|
if (f == NULL) {
|
|
perror(argv[1]);
|
|
return 3;
|
|
}
|
|
|
|
fwrite(buf, size, 1, f);
|
|
fclose(f);
|
|
|
|
if (bootcode <= 6) {
|
|
printf("%i\t%s\n", bootcode + 6100, argv[i]);
|
|
} else {
|
|
printf("iQue %i\t%s\n", bootcode - 6, argv[i]);
|
|
}
|
|
|
|
free(buf);
|
|
}
|
|
|
|
return 0;
|
|
}
|