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CD-ROM: Fix CRC and parity checking for XA Mode 2 Form 1 sectors.

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This commit is contained in:
OBattler
2025-07-24 16:49:01 +02:00
parent 91d2af521d
commit fb00027eff
3 changed files with 33 additions and 36 deletions
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39
src/cdrom/cdrom.c
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@@ -295,7 +295,7 @@ msf_to_bcd(int *m, int *s, int *f)
void
cdrom_compute_ecc_block(cdrom_t *dev, uint8_t *parity, const uint8_t *data,
uint32_t major_count, uint32_t minor_count,
uint32_t major_mult, uint32_t minor_inc)
uint32_t major_mult, uint32_t minor_inc, int m2f1)
{
uint32_t size = major_count * minor_count;
@@ -308,6 +308,9 @@ cdrom_compute_ecc_block(cdrom_t *dev, uint8_t *parity, const uint8_t *data,
for (uint32_t minor = 0; minor < minor_count; ++minor) {
uint8_t temp = data[index];
if (m2f1 && (index < 4))
temp = 0x00;
index += minor_inc;
if (index >= size)
@@ -323,14 +326,14 @@ cdrom_compute_ecc_block(cdrom_t *dev, uint8_t *parity, const uint8_t *data,
}
}
extern void
cdrom_generate_ecc_data(cdrom_t *dev, const uint8_t *data)
static void
cdrom_generate_ecc_data(cdrom_t *dev, const uint8_t *data, int m2f1)
{
/* Compute ECC P code. */
cdrom_compute_ecc_block(dev, dev->p_parity, data, 86, 24, 2, 86);
cdrom_compute_ecc_block(dev, dev->p_parity, data, 86, 24, 2, 86, m2f1);
/* Compute ECC Q code. */
cdrom_compute_ecc_block(dev, dev->q_parity, data, 52, 43, 86, 88);
cdrom_compute_ecc_block(dev, dev->q_parity, data, 52, 43, 86, 88, m2f1);
}
static int
@@ -338,21 +341,23 @@ cdrom_is_sector_good(cdrom_t *dev, const uint8_t *b, const uint8_t mode2, const
{
int ret = 1;
if (mode2 && (form == 1)) {
const uint32_t crc = cdrom_crc32(0xffffffff, b, 2072) ^ 0xffffffff;
if (!mode2 || (form != 1)) {
if (mode2 && (form == 1)) {
const uint32_t crc = cdrom_crc32(0xffffffff, &(b[16]), 2056) ^ 0xffffffff;
ret = ret && (crc == (*(uint32_t *) &(b[2072])));
} else if (!mode2) {
const uint32_t crc = cdrom_crc32(0xffffffff, b, 2064) ^ 0xffffffff;
ret = ret && (crc == (*(uint32_t *) &(b[2072])));
} else if (!mode2) {
const uint32_t crc = cdrom_crc32(0xffffffff, b, 2064) ^ 0xffffffff;
ret = ret && (crc == (*(uint32_t *) &(b[2064])));
ret = ret && (crc == (*(uint32_t *) &(b[2064])));
}
cdrom_generate_ecc_data(dev, &(b[12]), mode2 && (form == 1));
ret = ret && !memcmp(dev->p_parity, &(b[2076]), 172);
ret = ret && !memcmp(dev->q_parity, &(b[2248]), 104);
}
cdrom_generate_ecc_data(dev, &(b[12]));
ret = ret && !memcmp(dev->p_parity, &(b[2076]), 172);
ret = ret && !memcmp(dev->q_parity, &(b[2248]), 104);
return ret;
}
@@ -379,7 +384,7 @@ read_data(cdrom_t *dev, const uint32_t lba, int check)
else if (dev->raw_buffer[dev->cur_buf ^ 1][0x0012] ==
dev->raw_buffer[dev->cur_buf ^ 1][0x0016])
form = ((dev->raw_buffer[dev->cur_buf ^ 1][0x0012] &
0x20) >> 5) + 1;
0x20) >> 5) + 1;
} else if (dev->raw_buffer[dev->cur_buf ^ 1][0x000f] == 0x02)
dev->mode2 = 1;