From 90265546e6bb75ac5e4dac25925458e5198e6cd4 Mon Sep 17 00:00:00 2001 From: OBattler Date: Thu, 17 Apr 2025 00:18:38 +0200 Subject: [PATCH] CD-ROM: Do not stop playing on a READ command that immediately terminates with an "illegal mode for this track" error, fixes track skipping in the Windows 95 CD Player. --- src/cdrom/cdrom.c | 89 +++++++++++++++++++++++++++------------ src/include/86box/cdrom.h | 2 + src/scsi/scsi_cdrom.c | 17 ++++++++ 3 files changed, 80 insertions(+), 28 deletions(-) diff --git a/src/cdrom/cdrom.c b/src/cdrom/cdrom.c index b30d93812..644a8e245 100644 --- a/src/cdrom/cdrom.c +++ b/src/cdrom/cdrom.c @@ -2274,6 +2274,65 @@ cdrom_read_disc_info_toc(cdrom_t *dev, uint8_t *b, return ret; } +static uint32_t +cdrom_msf_to_lba(const int sector, const int ismsf, + int cdrom_sector_type, const uint8_t vendor_type) +{ + int pos = sector; + uint32_t lba; + + if ((cdrom_sector_type & 0x0f) >= 0x08) { + mult = cdrom_sector_type >> 4; + pos /= mult; + } + + if (ismsf) { + const int m = (pos >> 16) & 0xff; + const int s = (pos >> 8) & 0xff; + const int f = pos & 0xff; + + lba = MSFtoLBA(m, s, f) - 150; + } else { + switch (vendor_type) { + case 0x00: + lba = pos; + break; + case 0x40: { + const int m = bcd2bin((pos >> 24) & 0xff); + const int s = bcd2bin((pos >> 16) & 0xff); + const int f = bcd2bin((pos >> 8) & 0xff); + + lba = MSFtoLBA(m, s, f) - 150; + break; + } case 0x80: + lba = bcd2bin((pos >> 24) & 0xff); + break; + /* Never used values but the compiler complains. */ + default: + lba = 0; + } + } + + return lba; +} + +int +cdrom_is_track_audio(cdrom_t *dev, const int sector, + const int ismsf, int cdrom_sector_type, + const uint8_t vendor_type) +{ + int audio = 0; + uint32_t lba = cdrom_msf_to_lba(sector, ismsf, + cdrom_sector_type, vendor_type); + + if (dev->ops->get_track_type) + audio = dev->ops->get_track_type(dev->local, lba); + + audio &= CD_TRACK_AUDIO; + + return audio; +} + int cdrom_readsector_raw(cdrom_t *dev, uint8_t *buffer, const int sector, const int ismsf, int cdrom_sector_type, const int cdrom_sector_flags, @@ -2298,38 +2357,12 @@ cdrom_readsector_raw(cdrom_t *dev, uint8_t *buffer, const int sector, const int uint8_t *temp_b; uint8_t *b = temp_b = buffer; int audio = 0; - uint32_t lba; + uint32_t lba = cdrom_msf_to_lba(sector, ismsf, + cdrom_sector_type, vendor_type); int mode2 = 0; *len = 0; - if (ismsf) { - const int m = (pos >> 16) & 0xff; - const int s = (pos >> 8) & 0xff; - const int f = pos & 0xff; - - lba = MSFtoLBA(m, s, f) - 150; - } else { - switch (vendor_type) { - case 0x00: - lba = pos; - break; - case 0x40: { - const int m = bcd2bin((pos >> 24) & 0xff); - const int s = bcd2bin((pos >> 16) & 0xff); - const int f = bcd2bin((pos >> 8) & 0xff); - - lba = MSFtoLBA(m, s, f) - 150; - break; - } case 0x80: - lba = bcd2bin((pos >> 24) & 0xff); - break; - /* Never used values but the compiler complains. */ - default: - lba = 0; - } - } - if (dev->ops->get_track_type) audio = dev->ops->get_track_type(dev->local, lba); diff --git a/src/include/86box/cdrom.h b/src/include/86box/cdrom.h index 30c6476fb..5ff4170a2 100644 --- a/src/include/86box/cdrom.h +++ b/src/include/86box/cdrom.h @@ -425,6 +425,8 @@ extern uint8_t cdrom_mitsumi_audio_play(cdrom_t *dev, uint32_t pos, uint #endif extern uint8_t cdrom_read_disc_info_toc(cdrom_t *dev, uint8_t *b, const uint8_t track, const int type); +extern int cdrom_is_track_audio(cdrom_t *dev, const int sector, const int ismsf, + int cdrom_sector_type, const uint8_t vendor_type); extern int cdrom_readsector_raw(cdrom_t *dev, uint8_t *buffer, const int sector, const int ismsf, int cdrom_sector_type, const int cdrom_sector_flags, int *len, const uint8_t vendor_type); diff --git a/src/scsi/scsi_cdrom.c b/src/scsi/scsi_cdrom.c index 246f185e8..95c8c3640 100644 --- a/src/scsi/scsi_cdrom.c +++ b/src/scsi/scsi_cdrom.c @@ -2610,6 +2610,11 @@ scsi_cdrom_command(scsi_common_t *sc, const uint8_t *cdb) dev->sector_len = 256; dev->sector_pos = ((((uint32_t) cdb[1]) & 0x1f) << 16) | (((uint32_t) cdb[2]) << 8) | ((uint32_t) cdb[3]); + if (cdrom_is_track_audio(dev->drv, dev->sector_pos, msf, + dev->sector_type, 0x00)) { + scsi_cdrom_illegal_mode(dev); + ret = 0; + } scsi_cdrom_log(dev->log, "READ (6): Length: %i, LBA: %i\n", dev->sector_len, dev->sector_pos); break; @@ -2617,6 +2622,12 @@ scsi_cdrom_command(scsi_common_t *sc, const uint8_t *cdb) dev->sector_len = (cdb[7] << 8) | cdb[8]; dev->sector_pos = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5]; + if (cdrom_is_track_audio(dev->drv, dev->sector_pos, msf, + dev->sector_type, dev->use_cdb_9 ? + (cdb[9] & 0xc0) : 0x00)) { + scsi_cdrom_illegal_mode(dev); + ret = 0; + } scsi_cdrom_log(dev->log, "READ (10): Length: %i, LBA: %i\n", dev->sector_len, dev->sector_pos); break; @@ -2627,6 +2638,12 @@ scsi_cdrom_command(scsi_common_t *sc, const uint8_t *cdb) dev->sector_pos = (((uint32_t) cdb[2]) << 24) | (((uint32_t) cdb[3]) << 16) | (((uint32_t) cdb[4]) << 8) | ((uint32_t) cdb[5]); + if (cdrom_is_track_audio(dev->drv, dev->sector_pos, msf, + dev->sector_type, dev->use_cdb_9 ? + (cdb[9] & 0xc0) : 0x00)) { + scsi_cdrom_illegal_mode(dev); + ret = 0; + } scsi_cdrom_log(dev->log, "READ (12): Length: %i, LBA: %i\n", dev->sector_len, dev->sector_pos); break;