/* * Copyright (C) 2006 Michael Brown . * Copyright (C) 2020 longpanda . * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301, USA. * * You can also choose to distribute this program under the terms of * the Unmodified Binary Distribution Licence (as given in the file * COPYING.UBDL), provided that you have satisfied its requirements. */ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "ventoy_int13.h" static unsigned int g_drive_map1 = 0; static unsigned int g_drive_map2 = 0; /** @file * * INT 13 emulation * * This module provides a mechanism for exporting block devices via * the BIOS INT 13 disk interrupt interface. * */ /** INT 13 SAN device private data */ struct int13_data { /** BIOS natural drive number (0x00-0xff) * * This is the drive number that would have been assigned by * 'naturally' appending the drive to the end of the BIOS * drive list. * * If the emulated drive replaces a preexisting drive, this is * the drive number that the preexisting drive gets remapped * to. */ unsigned int natural_drive; /** Number of cylinders * * The cylinder number field in an INT 13 call is ten bits * wide, giving a maximum of 1024 cylinders. Conventionally, * when the 7.8GB limit of a CHS address is exceeded, it is * the number of cylinders that is increased beyond the * addressable limit. */ unsigned int cylinders; /** Number of heads * * The head number field in an INT 13 call is eight bits wide, * giving a maximum of 256 heads. However, apparently all * versions of MS-DOS up to and including Win95 fail with 256 * heads, so the maximum encountered in practice is 255. */ unsigned int heads; /** Number of sectors per track * * The sector number field in an INT 13 call is six bits wide, * giving a maximum of 63 sectors, since sector numbering * (unlike head and cylinder numbering) starts at 1, not 0. */ unsigned int sectors_per_track; /** Address of El Torito boot catalog (if any) */ unsigned int boot_catalog; /** Status of last operation */ int last_status; }; /** Vector for chaining to other INT 13 handlers */ static struct segoff __text16 ( int13_vector ); #define int13_vector __use_text16 ( int13_vector ) /** Assembly wrapper */ extern void int13_wrapper ( void ); /** Dummy floppy disk parameter table */ static struct int13_fdd_parameters __data16 ( int13_fdd_params ) = { /* 512 bytes per sector */ .bytes_per_sector = 0x02, /* Highest sectors per track that we ever return */ .sectors_per_track = 48, }; #define int13_fdd_params __use_data16 ( int13_fdd_params ) /** * Equipment word * * This is a cached copy of the BIOS Data Area equipment word at * 40:10. */ static uint16_t equipment_word; /** * Number of BIOS floppy disk drives * * This is derived from the equipment word. It is held in .text16 to * allow for easy access by the INT 13,08 wrapper. */ static uint8_t __text16 ( num_fdds ); #define num_fdds __use_text16 ( num_fdds ) /** * Number of BIOS hard disk drives * * This is a cached copy of the BIOS Data Area number of hard disk * drives at 40:75. It is held in .text16 to allow for easy access by * the INT 13,08 wrapper. */ static uint8_t __text16 ( num_drives ); #define num_drives __use_text16 ( num_drives ) static struct san_device *g_sandev; /** * Calculate SAN device capacity (limited to 32 bits) * * @v sandev SAN device * @ret blocks Number of blocks */ static inline uint32_t int13_capacity32 ( struct san_device *sandev ) { uint64_t capacity = sandev_capacity ( sandev ); return ( ( capacity <= 0xffffffffUL ) ? capacity : 0xffffffff ); } /** * Test if SAN device is a floppy disk drive * * @v sandev SAN device * @ret is_fdd SAN device is a floppy disk drive */ static inline int int13_is_fdd ( struct san_device *sandev ) { (void)sandev; return 0; } #if 0 /** * Guess INT 13 hard disk drive geometry * * @v sandev SAN device * @v scratch Scratch area for single-sector reads * @ret heads Guessed number of heads * @ret sectors Guessed number of sectors per track * @ret rc Return status code * * Guesses the drive geometry by inspecting the partition table. */ static int int13_guess_geometry_hdd ( struct san_device *sandev, void *scratch, unsigned int *heads, unsigned int *sectors ) { struct master_boot_record *mbr = scratch; struct partition_table_entry *partition; unsigned int i; unsigned int start_cylinder; unsigned int start_head; unsigned int start_sector; unsigned int end_head; unsigned int end_sector; int rc; /* Read partition table */ if ( ( rc = sandev_read ( sandev, 0, 1, virt_to_user ( mbr ) ) ) != 0 ) { DBGC ( sandev, "INT13 drive %02x could not read " "partition table to guess geometry: %s\n", sandev->drive, strerror ( rc ) ); return rc; } DBGC2 ( sandev, "INT13 drive %02x has MBR:\n", sandev->drive ); DBGC2_HDA ( sandev, 0, mbr, sizeof ( *mbr ) ); DBGC ( sandev, "INT13 drive %02x has signature %08x\n", sandev->drive, mbr->signature ); /* Scan through partition table and modify guesses for * heads and sectors_per_track if we find any used * partitions. */ *heads = 0; *sectors = 0; for ( i = 0 ; i < 4 ; i++ ) { /* Skip empty partitions */ partition = &mbr->partitions[i]; if ( ! partition->type ) continue; /* If partition starts on cylinder 0 then we can * unambiguously determine the number of sectors. */ start_cylinder = PART_CYLINDER ( partition->chs_start ); start_head = PART_HEAD ( partition->chs_start ); start_sector = PART_SECTOR ( partition->chs_start ); if ( ( start_cylinder == 0 ) && ( start_head != 0 ) ) { *sectors = ( ( partition->start + 1 - start_sector ) / start_head ); DBGC ( sandev, "INT13 drive %02x guessing C/H/S " "xx/xx/%d based on partition %d\n", sandev->drive, *sectors, ( i + 1 ) ); } /* If partition ends on a higher head or sector number * than our current guess, then increase the guess. */ end_head = PART_HEAD ( partition->chs_end ); end_sector = PART_SECTOR ( partition->chs_end ); if ( ( end_head + 1 ) > *heads ) { *heads = ( end_head + 1 ); DBGC ( sandev, "INT13 drive %02x guessing C/H/S " "xx/%d/xx based on partition %d\n", sandev->drive, *heads, ( i + 1 ) ); } if ( end_sector > *sectors ) { *sectors = end_sector; DBGC ( sandev, "INT13 drive %02x guessing C/H/S " "xx/xx/%d based on partition %d\n", sandev->drive, *sectors, ( i + 1 ) ); } } /* Default guess is xx/255/63 */ if ( ! *heads ) *heads = 255; if ( ! *sectors ) *sectors = 63; return 0; } /** Recognised floppy disk geometries */ static const struct int13_fdd_geometry int13_fdd_geometries[] = { INT13_FDD_GEOMETRY ( 40, 1, 8 ), INT13_FDD_GEOMETRY ( 40, 1, 9 ), INT13_FDD_GEOMETRY ( 40, 2, 8 ), INT13_FDD_GEOMETRY ( 40, 1, 9 ), INT13_FDD_GEOMETRY ( 80, 2, 8 ), INT13_FDD_GEOMETRY ( 80, 2, 9 ), INT13_FDD_GEOMETRY ( 80, 2, 15 ), INT13_FDD_GEOMETRY ( 80, 2, 18 ), INT13_FDD_GEOMETRY ( 80, 2, 20 ), INT13_FDD_GEOMETRY ( 80, 2, 21 ), INT13_FDD_GEOMETRY ( 82, 2, 21 ), INT13_FDD_GEOMETRY ( 83, 2, 21 ), INT13_FDD_GEOMETRY ( 80, 2, 22 ), INT13_FDD_GEOMETRY ( 80, 2, 23 ), INT13_FDD_GEOMETRY ( 80, 2, 24 ), INT13_FDD_GEOMETRY ( 80, 2, 36 ), INT13_FDD_GEOMETRY ( 80, 2, 39 ), INT13_FDD_GEOMETRY ( 80, 2, 40 ), INT13_FDD_GEOMETRY ( 80, 2, 44 ), INT13_FDD_GEOMETRY ( 80, 2, 48 ), }; /** * Guess INT 13 floppy disk drive geometry * * @v sandev SAN device * @ret heads Guessed number of heads * @ret sectors Guessed number of sectors per track * @ret rc Return status code * * Guesses the drive geometry by inspecting the disk size. */ static int int13_guess_geometry_fdd ( struct san_device *sandev, unsigned int *heads, unsigned int *sectors ) { unsigned int blocks = sandev_capacity ( sandev ); const struct int13_fdd_geometry *geometry; unsigned int cylinders; unsigned int i; /* Look for a match against a known geometry */ for ( i = 0 ; i < ( sizeof ( int13_fdd_geometries ) / sizeof ( int13_fdd_geometries[0] ) ) ; i++ ) { geometry = &int13_fdd_geometries[i]; cylinders = INT13_FDD_CYLINDERS ( geometry ); *heads = INT13_FDD_HEADS ( geometry ); *sectors = INT13_FDD_SECTORS ( geometry ); if ( ( cylinders * (*heads) * (*sectors) ) == blocks ) { DBGC ( sandev, "INT13 drive %02x guessing C/H/S " "%d/%d/%d based on size %dK\n", sandev->drive, cylinders, *heads, *sectors, ( blocks / 2 ) ); return 0; } } /* Otherwise, assume a partial disk image in the most common * format (1440K, 80/2/18). */ *heads = 2; *sectors = 18; DBGC ( sandev, "INT13 drive %02x guessing C/H/S xx/%d/%d based on size " "%dK\n", sandev->drive, *heads, *sectors, ( blocks / 2 ) ); return 0; } /** * Guess INT 13 drive geometry * * @v sandev SAN device * @v scratch Scratch area for single-sector reads * @ret rc Return status code */ static int int13_guess_geometry ( struct san_device *sandev, void *scratch ) { struct int13_data *int13 = sandev->priv; unsigned int guessed_heads; unsigned int guessed_sectors; unsigned int blocks; unsigned int blocks_per_cyl; int rc; /* Guess geometry according to drive type */ if ( int13_is_fdd ( sandev ) ) { if ( ( rc = int13_guess_geometry_fdd ( sandev, &guessed_heads, &guessed_sectors )) != 0) return rc; } else { if ( ( rc = int13_guess_geometry_hdd ( sandev, scratch, &guessed_heads, &guessed_sectors )) != 0) return rc; } /* Apply guesses if no geometry already specified */ if ( ! int13->heads ) int13->heads = guessed_heads; if ( ! int13->sectors_per_track ) int13->sectors_per_track = guessed_sectors; if ( ! int13->cylinders ) { /* Avoid attempting a 64-bit divide on a 32-bit system */ blocks = int13_capacity32 ( sandev ); blocks_per_cyl = ( int13->heads * int13->sectors_per_track ); assert ( blocks_per_cyl != 0 ); int13->cylinders = ( blocks / blocks_per_cyl ); if ( int13->cylinders > 1024 ) int13->cylinders = 1024; } return 0; } #endif /* #if 0 */ /** * Update BIOS drive count */ void int13_sync_num_drives ( void ) { struct san_device *sandev; struct int13_data *int13; uint8_t *counter; uint8_t max_drive; uint8_t required; /* Get current drive counts */ get_real ( equipment_word, BDA_SEG, BDA_EQUIPMENT_WORD ); get_real ( num_drives, BDA_SEG, BDA_NUM_DRIVES ); num_fdds = ( ( equipment_word & 0x0001 ) ? ( ( ( equipment_word >> 6 ) & 0x3 ) + 1 ) : 0 ); /* Ensure count is large enough to cover all of our SAN devices */ for_each_sandev ( sandev ) { int13 = sandev->priv; counter = ( int13_is_fdd ( sandev ) ? &num_fdds : &num_drives ); max_drive = sandev->drive; if ( max_drive < int13->natural_drive ) max_drive = int13->natural_drive; required = ( ( max_drive & 0x7f ) + 1 ); if ( *counter < required ) { *counter = required; DBGC ( sandev, "INT13 drive %02x added to drive count: " "%d HDDs, %d FDDs\n", sandev->drive, num_drives, num_fdds ); } } /* Update current drive count */ equipment_word &= ~( ( 0x3 << 6 ) | 0x0001 ); if ( num_fdds ) { equipment_word |= ( 0x0001 | ( ( ( num_fdds - 1 ) & 0x3 ) << 6 ) ); } put_real ( equipment_word, BDA_SEG, BDA_EQUIPMENT_WORD ); put_real ( num_drives, BDA_SEG, BDA_NUM_DRIVES ); } /** * Check number of drives */ void int13_check_num_drives ( void ) { uint16_t check_equipment_word; uint8_t check_num_drives; get_real ( check_equipment_word, BDA_SEG, BDA_EQUIPMENT_WORD ); get_real ( check_num_drives, BDA_SEG, BDA_NUM_DRIVES ); if ( ( check_equipment_word != equipment_word ) || ( check_num_drives != num_drives ) ) { int13_sync_num_drives(); } } /** * INT 13, 00 - Reset disk system * * @v sandev SAN device * @ret status Status code */ static int int13_reset ( struct san_device *sandev, struct i386_all_regs *ix86 __unused ) { int rc; DBGC2 ( sandev, "Reset drive\n" ); /* Reset SAN device */ if ( ( rc = sandev_reset ( sandev ) ) != 0 ) return -INT13_STATUS_RESET_FAILED; return 0; } /** * INT 13, 01 - Get status of last operation * * @v sandev SAN device * @ret status Status code */ static int int13_get_last_status ( struct san_device *sandev, struct i386_all_regs *ix86 __unused ) { struct int13_data *int13 = sandev->priv; DBGC2 ( sandev, "Get status of last operation\n" ); return int13->last_status; } /** * Read / write sectors * * @v sandev SAN device * @v al Number of sectors to read or write (must be nonzero) * @v ch Low bits of cylinder number * @v cl (bits 7:6) High bits of cylinder number * @v cl (bits 5:0) Sector number * @v dh Head number * @v es:bx Data buffer * @v sandev_rw SAN device read/write method * @ret status Status code * @ret al Number of sectors read or written */ static int int13_rw_sectors ( struct san_device *sandev, struct i386_all_regs *ix86, int ( * sandev_rw ) ( struct san_device *sandev, uint64_t lba, unsigned int count, userptr_t buffer ) ) { struct int13_data *int13 = sandev->priv; unsigned int cylinder, head, sector; unsigned long lba; unsigned int count; userptr_t buffer; int rc; /* Validate blocksize */ if ( sandev_blksize ( sandev ) != INT13_BLKSIZE ) { DBGC ( sandev, "\nINT 13 drive %02x invalid blocksize (%zd) " "for non-extended read/write\n", sandev->drive, sandev_blksize ( sandev ) ); return -INT13_STATUS_INVALID; } /* Calculate parameters */ cylinder = ( ( ( ix86->regs.cl & 0xc0 ) << 2 ) | ix86->regs.ch ); head = ix86->regs.dh; sector = ( ix86->regs.cl & 0x3f ); if ( ( cylinder >= int13->cylinders ) || ( head >= int13->heads ) || ( sector < 1 ) || ( sector > int13->sectors_per_track ) ) { DBGC ( sandev, "C/H/S %d/%d/%d out of range for geometry " "%d/%d/%d\n", cylinder, head, sector, int13->cylinders, int13->heads, int13->sectors_per_track ); return -INT13_STATUS_INVALID; } lba = ( ( ( ( cylinder * int13->heads ) + head ) * int13->sectors_per_track ) + sector - 1 ); count = ix86->regs.al; buffer = real_to_user ( ix86->segs.es, ix86->regs.bx ); DBGC2 ( sandev, "C/H/S %d/%d/%d = LBA %08lx <-> %04x:%04x (count %d)\n", cylinder, head, sector, lba, ix86->segs.es, ix86->regs.bx, count ); /* Read from / write to block device */ if ( ( rc = sandev_rw ( sandev, lba, count, buffer ) ) != 0 ){ DBGC ( sandev, "INT13 drive %02x I/O failed: %s\n", sandev->drive, strerror ( rc ) ); return -INT13_STATUS_READ_ERROR; } return 0; } /** * INT 13, 02 - Read sectors * * @v sandev SAN device * @v al Number of sectors to read (must be nonzero) * @v ch Low bits of cylinder number * @v cl (bits 7:6) High bits of cylinder number * @v cl (bits 5:0) Sector number * @v dh Head number * @v es:bx Data buffer * @ret status Status code * @ret al Number of sectors read */ static int int13_read_sectors ( struct san_device *sandev, struct i386_all_regs *ix86 ) { DBGC2 ( sandev, "Read: " ); return int13_rw_sectors ( sandev, ix86, sandev_read ); } /** * INT 13, 03 - Write sectors * * @v sandev SAN device * @v al Number of sectors to write (must be nonzero) * @v ch Low bits of cylinder number * @v cl (bits 7:6) High bits of cylinder number * @v cl (bits 5:0) Sector number * @v dh Head number * @v es:bx Data buffer * @ret status Status code * @ret al Number of sectors written */ static int int13_write_sectors ( struct san_device *sandev, struct i386_all_regs *ix86 ) { DBGC2 ( sandev, "Write: " ); return int13_rw_sectors ( sandev, ix86, sandev_write ); } /** * INT 13, 08 - Get drive parameters * * @v sandev SAN device * @ret status Status code * @ret ch Low bits of maximum cylinder number * @ret cl (bits 7:6) High bits of maximum cylinder number * @ret cl (bits 5:0) Maximum sector number * @ret dh Maximum head number * @ret dl Number of drives */ static int int13_get_parameters ( struct san_device *sandev, struct i386_all_regs *ix86 ) { struct int13_data *int13 = sandev->priv; unsigned int max_cylinder = int13->cylinders - 1; unsigned int max_head = int13->heads - 1; unsigned int max_sector = int13->sectors_per_track; /* sic */ DBGC2 ( sandev, "Get drive parameters\n" ); /* Validate blocksize */ if ( sandev_blksize ( sandev ) != INT13_BLKSIZE ) { DBGC ( sandev, "\nINT 13 drive %02x invalid blocksize (%zd) " "for non-extended parameters\n", sandev->drive, sandev_blksize ( sandev ) ); return -INT13_STATUS_INVALID; } /* Common parameters */ ix86->regs.ch = ( max_cylinder & 0xff ); ix86->regs.cl = ( ( ( max_cylinder >> 8 ) << 6 ) | max_sector ); ix86->regs.dh = max_head; ix86->regs.dl = ( int13_is_fdd ( sandev ) ? num_fdds : num_drives ); /* Floppy-specific parameters */ if ( int13_is_fdd ( sandev ) ) { ix86->regs.bl = INT13_FDD_TYPE_1M44; ix86->segs.es = rm_ds; ix86->regs.di = __from_data16 ( &int13_fdd_params ); } return 0; } /** * INT 13, 15 - Get disk type * * @v sandev SAN device * @ret ah Type code * @ret cx:dx Sector count * @ret status Status code / disk type */ static int int13_get_disk_type ( struct san_device *sandev, struct i386_all_regs *ix86 ) { uint32_t blocks; DBGC2 ( sandev, "Get disk type\n" ); if ( int13_is_fdd ( sandev ) ) { return INT13_DISK_TYPE_FDD; } else { blocks = int13_capacity32 ( sandev ); ix86->regs.cx = ( blocks >> 16 ); ix86->regs.dx = ( blocks & 0xffff ); return INT13_DISK_TYPE_HDD; } } /** * INT 13, 41 - Extensions installation check * * @v sandev SAN device * @v bx 0x55aa * @ret bx 0xaa55 * @ret cx Extensions API support bitmap * @ret status Status code / API version */ static int int13_extension_check ( struct san_device *sandev __unused, struct i386_all_regs *ix86 ) { if ( ix86->regs.bx == 0x55aa ) { DBGC2 ( sandev, "INT13 extensions installation check\n" ); ix86->regs.bx = 0xaa55; ix86->regs.cx = ( INT13_EXTENSION_LINEAR | INT13_EXTENSION_EDD | INT13_EXTENSION_64BIT ); return INT13_EXTENSION_VER_3_0; } else { return -INT13_STATUS_INVALID; } } /** * Extended read / write * * @v sandev SAN device * @v ds:si Disk address packet * @v sandev_rw SAN device read/write method * @ret status Status code */ static int int13_extended_rw ( struct san_device *sandev, struct i386_all_regs *ix86, int ( * sandev_rw ) ( struct san_device *sandev, uint64_t lba, unsigned int count, userptr_t buffer ) ) { struct int13_disk_address addr; uint8_t bufsize; uint64_t lba; unsigned long count; userptr_t buffer; int rc; /* Extended reads are not allowed on floppy drives. * ELTORITO.SYS seems to assume that we are really a CD-ROM if * we support extended reads for a floppy drive. */ if ( int13_is_fdd ( sandev ) ) return -INT13_STATUS_INVALID; /* Get buffer size */ get_real ( bufsize, ix86->segs.ds, ( ix86->regs.si + offsetof ( typeof ( addr ), bufsize ) ) ); if ( bufsize < offsetof ( typeof ( addr ), buffer_phys ) ) { DBGC2 ( sandev, "\n", bufsize ); return -INT13_STATUS_INVALID; } /* Read parameters from disk address structure */ memset ( &addr, 0, sizeof ( addr ) ); copy_from_real ( &addr, ix86->segs.ds, ix86->regs.si, bufsize ); lba = addr.lba; DBGC2 ( sandev, "LBA %08llx <-> ", ( ( unsigned long long ) lba ) ); if ( ( addr.count == 0xff ) || ( ( addr.buffer.segment == 0xffff ) && ( addr.buffer.offset == 0xffff ) ) ) { buffer = phys_to_user ( addr.buffer_phys ); DBGC2 ( sandev, "%08llx", ( ( unsigned long long ) addr.buffer_phys ) ); } else { buffer = real_to_user ( addr.buffer.segment, addr.buffer.offset ); DBGC2 ( sandev, "%04x:%04x", addr.buffer.segment, addr.buffer.offset ); } if ( addr.count <= 0x7f ) { count = addr.count; } else if ( addr.count == 0xff ) { count = addr.long_count; } else { DBGC2 ( sandev, " \n", addr.count ); return -INT13_STATUS_INVALID; } DBGC2 ( sandev, " (count %ld)\n", count ); /* Read from / write to block device */ if ( ( rc = sandev_rw ( sandev, lba, count, buffer ) ) != 0 ) { DBGC ( sandev, "INT13 drive %02x extended I/O failed: %s\n", sandev->drive, strerror ( rc ) ); /* Record that no blocks were transferred successfully */ addr.count = 0; put_real ( addr.count, ix86->segs.ds, ( ix86->regs.si + offsetof ( typeof ( addr ), count ) ) ); return -INT13_STATUS_READ_ERROR; } copy_to_real (ix86->segs.ds, ix86->regs.si, &addr, bufsize ); return 0; } /** * INT 13, 42 - Extended read * * @v sandev SAN device * @v ds:si Disk address packet * @ret status Status code */ static int int13_extended_read ( struct san_device *sandev, struct i386_all_regs *ix86 ) { DBGC2 ( sandev, "Extended read: " ); return int13_extended_rw ( sandev, ix86, sandev_read ); } /** * INT 13, 43 - Extended write * * @v sandev SAN device * @v ds:si Disk address packet * @ret status Status code */ static int int13_extended_write ( struct san_device *sandev, struct i386_all_regs *ix86 ) { DBGC2 ( sandev, "Extended write: " ); return int13_extended_rw ( sandev, ix86, sandev_write ); } /** * INT 13, 44 - Verify sectors * * @v sandev SAN device * @v ds:si Disk address packet * @ret status Status code */ static int int13_extended_verify ( struct san_device *sandev, struct i386_all_regs *ix86 ) { struct int13_disk_address addr; uint64_t lba; unsigned long count; /* Read parameters from disk address structure */ if ( DBG_EXTRA ) { copy_from_real ( &addr, ix86->segs.ds, ix86->regs.si, sizeof ( addr )); lba = addr.lba; count = addr.count; DBGC2 ( sandev, "Verify: LBA %08llx (count %ld)\n", ( ( unsigned long long ) lba ), count ); } /* We have no mechanism for verifying sectors */ return -INT13_STATUS_INVALID; } /** * INT 13, 44 - Extended seek * * @v sandev SAN device * @v ds:si Disk address packet * @ret status Status code */ static int int13_extended_seek ( struct san_device *sandev, struct i386_all_regs *ix86 ) { struct int13_disk_address addr; uint64_t lba; unsigned long count; /* Read parameters from disk address structure */ if ( DBG_EXTRA ) { copy_from_real ( &addr, ix86->segs.ds, ix86->regs.si, sizeof ( addr )); lba = addr.lba; count = addr.count; DBGC2 ( sandev, "Seek: LBA %08llx (count %ld)\n", ( ( unsigned long long ) lba ), count ); } /* Ignore and return success */ return 0; } /** * Build device path information * * @v sandev SAN device * @v dpi Device path information * @ret rc Return status code */ static int int13_device_path_info ( struct san_device *sandev, struct edd_device_path_information *dpi ) { struct san_path *sanpath; struct device *device; struct device_description *desc; unsigned int i; uint8_t sum = 0; int rc; return -ECANCELED; /* Reopen block device if necessary */ if ( sandev_needs_reopen ( sandev ) && ( ( rc = sandev_reopen ( sandev ) ) != 0 ) ) return rc; sanpath = sandev->active; assert ( sanpath != NULL ); /* Get underlying hardware device */ device = identify_device ( &sanpath->block ); if ( ! device ) { DBGC ( sandev, "INT13 drive %02x cannot identify hardware " "device\n", sandev->drive ); return -ENODEV; } /* Fill in bus type and interface path */ desc = &device->desc; switch ( desc->bus_type ) { case BUS_TYPE_PCI: dpi->host_bus_type.type = EDD_BUS_TYPE_PCI; dpi->interface_path.pci.bus = PCI_BUS ( desc->location ); dpi->interface_path.pci.slot = PCI_SLOT ( desc->location ); dpi->interface_path.pci.function = PCI_FUNC ( desc->location ); dpi->interface_path.pci.channel = 0xff; /* unused */ break; default: DBGC ( sandev, "INT13 drive %02x unrecognised bus type %d\n", sandev->drive, desc->bus_type ); return -ENOTSUP; } /* Get EDD block device description */ if ( ( rc = edd_describe ( &sanpath->block, &dpi->interface_type, &dpi->device_path ) ) != 0 ) { DBGC ( sandev, "INT13 drive %02x cannot identify block device: " "%s\n", sandev->drive, strerror ( rc ) ); return rc; } /* Fill in common fields and fix checksum */ dpi->key = EDD_DEVICE_PATH_INFO_KEY; dpi->len = sizeof ( *dpi ); for ( i = 0 ; i < sizeof ( *dpi ) ; i++ ) sum += *( ( ( uint8_t * ) dpi ) + i ); dpi->checksum -= sum; return 0; } /** * INT 13, 48 - Get extended parameters * * @v sandev SAN device * @v ds:si Drive parameter table * @ret status Status code */ static int int13_get_extended_parameters ( struct san_device *sandev, struct i386_all_regs *ix86 ) { struct int13_data *int13 = sandev->priv; struct int13_disk_parameters params; struct segoff address; size_t len = sizeof ( params ); uint16_t bufsize; int rc; /* Get buffer size */ get_real ( bufsize, ix86->segs.ds, ( ix86->regs.si + offsetof ( typeof ( params ), bufsize ))); DBGC2 ( sandev, "Get extended drive parameters to %04x:%04x+%02x\n", ix86->segs.ds, ix86->regs.si, bufsize ); /* Build drive parameters */ memset ( ¶ms, 0, sizeof ( params ) ); params.flags = INT13_FL_DMA_TRANSPARENT; if ( ( int13->cylinders < 1024 ) && ( sandev_capacity ( sandev ) <= INT13_MAX_CHS_SECTORS ) ) { params.flags |= INT13_FL_CHS_VALID; } params.cylinders = int13->cylinders; params.heads = int13->heads; params.sectors_per_track = int13->sectors_per_track; params.sectors = sandev_capacity ( sandev ); params.sector_size = sandev_blksize ( sandev ); memset ( ¶ms.dpte, 0xff, sizeof ( params.dpte ) ); if ( ( rc = int13_device_path_info ( sandev, ¶ms.dpi ) ) != 0 ) { DBGC ( sandev, "INT13 drive %02x could not provide device " "path information: %s\n", sandev->drive, strerror ( rc ) ); len = offsetof ( typeof ( params ), dpi ); } /* Calculate returned "buffer size" (which will be less than * the length actually copied if device path information is * present). */ if ( bufsize < offsetof ( typeof ( params ), dpte ) ) return -INT13_STATUS_INVALID; if ( bufsize < offsetof ( typeof ( params ), dpi ) ) { params.bufsize = offsetof ( typeof ( params ), dpte ); } else { params.bufsize = offsetof ( typeof ( params ), dpi ); } DBGC ( sandev, "INT 13 drive %02x described using extended " "parameters:\n", sandev->drive ); address.segment = ix86->segs.ds; address.offset = ix86->regs.si; DBGC_HDA ( sandev, address, ¶ms, len ); /* Return drive parameters */ if ( len > bufsize ) len = bufsize; copy_to_real ( ix86->segs.ds, ix86->regs.si, ¶ms, len ); return 0; } /** * INT 13, 4b - Get status or terminate CD-ROM emulation * * @v sandev SAN device * @v ds:si Specification packet * @ret status Status code */ static int int13_cdrom_status_terminate ( struct san_device *sandev, struct i386_all_regs *ix86 ) { struct int13_cdrom_specification specification; DBGC2 ( sandev, "Get CD-ROM emulation status to %04x:%04x%s\n", ix86->segs.ds, ix86->regs.si, ( ix86->regs.al ? "" : " and terminate" ) ); /* Fail if we are not a CD-ROM */ if ( ! sandev->is_cdrom ) { DBGC ( sandev, "INT13 drive %02x is not a CD-ROM\n", sandev->drive ); return -INT13_STATUS_INVALID; } /* Build specification packet */ memset ( &specification, 0, sizeof ( specification ) ); specification.size = sizeof ( specification ); specification.drive = sandev->drive; /* Return specification packet */ copy_to_real ( ix86->segs.ds, ix86->regs.si, &specification, sizeof ( specification ) ); return 0; } /** * INT 13, 4d - Read CD-ROM boot catalog * * @v sandev SAN device * @v ds:si Command packet * @ret status Status code */ static int int13_cdrom_read_boot_catalog ( struct san_device *sandev, struct i386_all_regs *ix86 ) { struct int13_data *int13 = sandev->priv; struct int13_cdrom_boot_catalog_command command; unsigned int start; int rc; /* Read parameters from command packet */ copy_from_real ( &command, ix86->segs.ds, ix86->regs.si, sizeof ( command ) ); DBGC2 ( sandev, "Read CD-ROM boot catalog to %08x\n", command.buffer ); /* Fail if we have no boot catalog */ if ( ! int13->boot_catalog ) { DBGC ( sandev, "INT13 drive %02x has no boot catalog\n", sandev->drive ); return -INT13_STATUS_INVALID; } start = ( int13->boot_catalog + command.start ); /* Read from boot catalog */ if ( ( rc = sandev_read ( sandev, start, command.count, phys_to_user ( command.buffer ) ) ) != 0 ) { DBGC ( sandev, "INT13 drive %02x could not read boot catalog: " "%s\n", sandev->drive, strerror ( rc ) ); return -INT13_STATUS_READ_ERROR; } return 0; } /** * INT 13 handler * */ static __asmcall void int13 ( struct i386_all_regs *ix86 ) { int command = ix86->regs.ah; unsigned int bios_drive = ix86->regs.dl; struct san_device *sandev; struct int13_data *int13; int status; /* We simulate a cdrom, so no need to sync hd drive number */ //int13_check_num_drives(); if (bios_drive == VENTOY_BIOS_FAKE_DRIVE) { ix86->regs.dl = g_sandev->exdrive; return; } // drive swap if (g_drive_map1 >= 0x80 && g_drive_map2 >= 0x80) { if (bios_drive == g_drive_map1) { ix86->regs.dl = g_drive_map2; return; } else if (bios_drive == g_drive_map2) { ix86->regs.dl = g_drive_map1; return; } } for_each_sandev ( sandev ) { int13 = sandev->priv; if ( bios_drive != sandev->drive ) { /* Remap any accesses to this drive's natural number */ if ( bios_drive == int13->natural_drive ) { DBGC2 ( sandev, "INT13,%02x (%02x) remapped to " "(%02x)\n", ix86->regs.ah, bios_drive, sandev->drive ); ix86->regs.dl = sandev->drive; return; } else if ( ( ( bios_drive & 0x7f ) == 0x7f ) && ( command == INT13_CDROM_STATUS_TERMINATE ) && sandev->is_cdrom ) { /* Catch non-drive-specific CD-ROM calls */ } else { return; } } sandev->int13_command = command; sandev->x86_regptr = ix86; DBGC2 ( sandev, "INT13,%02x (%02x): ", ix86->regs.ah, bios_drive ); switch ( command ) { case INT13_RESET: status = int13_reset ( sandev, ix86 ); break; case INT13_GET_LAST_STATUS: status = int13_get_last_status ( sandev, ix86 ); break; case INT13_READ_SECTORS: status = int13_read_sectors ( sandev, ix86 ); break; case INT13_WRITE_SECTORS: status = int13_write_sectors ( sandev, ix86 ); break; case INT13_GET_PARAMETERS: status = int13_get_parameters ( sandev, ix86 ); break; case INT13_GET_DISK_TYPE: status = int13_get_disk_type ( sandev, ix86 ); break; case INT13_EXTENSION_CHECK: status = int13_extension_check ( sandev, ix86 ); break; case INT13_EXTENDED_READ: status = int13_extended_read ( sandev, ix86 ); break; case INT13_EXTENDED_WRITE: status = int13_extended_write ( sandev, ix86 ); break; case INT13_EXTENDED_VERIFY: status = int13_extended_verify ( sandev, ix86 ); break; case INT13_EXTENDED_SEEK: status = int13_extended_seek ( sandev, ix86 ); break; case INT13_GET_EXTENDED_PARAMETERS: status = int13_get_extended_parameters ( sandev, ix86 ); break; case INT13_CDROM_STATUS_TERMINATE: status = int13_cdrom_status_terminate ( sandev, ix86 ); break; case INT13_CDROM_READ_BOOT_CATALOG: status = int13_cdrom_read_boot_catalog ( sandev, ix86 ); break; default: DBGC2 ( sandev, "*** Unrecognised INT13 ***\n" ); status = -INT13_STATUS_INVALID; break; } /* Store status for INT 13,01 */ int13->last_status = status; /* Negative status indicates an error */ if ( status < 0 ) { status = -status; DBGC ( sandev, "INT13,%02x (%02x) failed with status " "%02x\n", ix86->regs.ah, sandev->drive, status ); } else { ix86->flags &= ~CF; } ix86->regs.ah = status; /* Set OF to indicate to wrapper not to chain this call */ ix86->flags |= OF; return; } } /** * Hook INT 13 handler * */ static void int13_hook_vector ( void ) { /* Assembly wrapper to call int13(). int13() sets OF if we * should not chain to the previous handler. (The wrapper * clears CF and OF before calling int13()). */ __asm__ __volatile__ ( TEXT16_CODE ( "\nint13_wrapper:\n\t" /* Preserve %ax and %dx for future reference */ "pushw %%bp\n\t" "movw %%sp, %%bp\n\t" "pushw %%ax\n\t" "pushw %%dx\n\t" /* Clear OF, set CF, call int13() */ "orb $0, %%al\n\t" "stc\n\t" VIRT_CALL ( int13 ) /* Chain if OF not set */ "jo 1f\n\t" "pushfw\n\t" "lcall *%%cs:int13_vector\n\t" "\n1:\n\t" /* Overwrite flags for iret */ "pushfw\n\t" "popw 6(%%bp)\n\t" /* Fix up %dl: * * INT 13,15 : do nothing if hard disk * INT 13,08 : load with number of drives * all others: restore original value */ "cmpb $0x15, -1(%%bp)\n\t" "jne 2f\n\t" "testb $0x80, -4(%%bp)\n\t" "jnz 3f\n\t" "\n2:\n\t" "movb -4(%%bp), %%dl\n\t" "cmpb $0x08, -1(%%bp)\n\t" "jne 3f\n\t" "testb $0x80, %%dl\n\t" "movb %%cs:num_drives, %%dl\n\t" "jnz 3f\n\t" "movb %%cs:num_fdds, %%dl\n\t" /* Return */ "\n3:\n\t" "movw %%bp, %%sp\n\t" "popw %%bp\n\t" "iret\n\t" ) : : ); hook_bios_interrupt ( 0x13, ( intptr_t ) int13_wrapper, &int13_vector ); } /** * Load and verify master boot record from INT 13 drive * * @v drive Drive number * @v address Boot code address to fill in * @ret rc Return status code */ static int int13_load_mbr ( unsigned int drive, struct segoff *address ) { uint16_t status; int discard_b, discard_c, discard_d; uint16_t magic; /* Use INT 13, 02 to read the MBR */ address->segment = 0; address->offset = 0x7c00; __asm__ __volatile__ ( REAL_CODE ( "pushw %%es\n\t" "pushl %%ebx\n\t" "popw %%bx\n\t" "popw %%es\n\t" "stc\n\t" "sti\n\t" "int $0x13\n\t" "sti\n\t" /* BIOS bugs */ "jc 1f\n\t" "xorw %%ax, %%ax\n\t" "\n1:\n\t" "popw %%es\n\t" ) : "=a" ( status ), "=b" ( discard_b ), "=c" ( discard_c ), "=d" ( discard_d ) : "a" ( 0x0201 ), "b" ( *address ), "c" ( 1 ), "d" ( drive ) ); if ( status ) { DBG ( "INT13 drive %02x could not read MBR (status %04x)\n", drive, status ); return -EIO; } /* Check magic signature */ get_real ( magic, address->segment, ( address->offset + offsetof ( struct master_boot_record, magic ) ) ); if ( magic != INT13_MBR_MAGIC ) { DBG ( "INT13 drive %02x does not contain a valid MBR\n", drive ); return -ENOEXEC; } return 0; } /** El Torito boot catalog command packet */ static struct int13_cdrom_boot_catalog_command __data16 ( eltorito_cmd ) = { .size = sizeof ( struct int13_cdrom_boot_catalog_command ), .count = 1, .buffer = 0x7c00, .start = 0, }; #define eltorito_cmd __use_data16 ( eltorito_cmd ) /** El Torito disk address packet */ static struct int13_disk_address __bss16 ( eltorito_address ); #define eltorito_address __use_data16 ( eltorito_address ) /** * Load and verify El Torito boot record from INT 13 drive * * @v drive Drive number * @v address Boot code address to fill in * @ret rc Return status code */ static int int13_load_eltorito ( unsigned int drive, struct segoff *address ) { struct { struct eltorito_validation_entry valid; struct eltorito_boot_entry boot; } __attribute__ (( packed )) catalog; uint16_t status; if (g_sandev && g_sandev->drive == drive) { copy_to_user(phys_to_user ( eltorito_cmd.buffer ), 0, g_sandev->boot_catalog_sector, sizeof(g_sandev->boot_catalog_sector)); } else { /* Use INT 13, 4d to read the boot catalog */ __asm__ __volatile__ ( REAL_CODE ( "stc\n\t" "sti\n\t" "int $0x13\n\t" "sti\n\t" /* BIOS bugs */ "jc 1f\n\t" "xorw %%ax, %%ax\n\t" "\n1:\n\t" ) : "=a" ( status ) : "a" ( 0x4d00 ), "d" ( drive ), "S" ( __from_data16 ( &eltorito_cmd ) ) ); if ( status ) { DBG ( "INT13 drive %02x could not read El Torito boot catalog " "(status %04x)\n", drive, status ); return -EIO; } } copy_from_user ( &catalog, phys_to_user ( eltorito_cmd.buffer ), 0, sizeof ( catalog ) ); /* Sanity checks */ if ( catalog.valid.platform_id != ELTORITO_PLATFORM_X86 ) { DBG ( "INT13 drive %02x El Torito specifies unknown platform " "%02x\n", drive, catalog.valid.platform_id ); return -ENOEXEC; } if ( catalog.boot.indicator != ELTORITO_BOOTABLE ) { DBG ( "INT13 drive %02x El Torito is not bootable\n", drive ); return -ENOEXEC; } if ( catalog.boot.media_type != ELTORITO_NO_EMULATION ) { DBG ( "INT13 drive %02x El Torito requires emulation " "type %02x\n", drive, catalog.boot.media_type ); return -ENOTSUP; } DBG ( "INT13 drive %02x El Torito boot image at LBA %08x (count %d)\n", drive, catalog.boot.start, catalog.boot.length ); address->segment = ( catalog.boot.load_segment ? catalog.boot.load_segment : 0x7c0 ); address->offset = 0; DBG ( "INT13 drive %02x El Torito boot image loads at %04x:%04x\n", drive, address->segment, address->offset ); /* Use INT 13, 42 to read the boot image */ eltorito_address.bufsize = offsetof ( typeof ( eltorito_address ), buffer_phys ); eltorito_address.count = catalog.boot.length; eltorito_address.buffer = *address; eltorito_address.lba = catalog.boot.start; __asm__ __volatile__ ( REAL_CODE ( "stc\n\t" "sti\n\t" "int $0x13\n\t" "sti\n\t" /* BIOS bugs */ "jc 1f\n\t" "xorw %%ax, %%ax\n\t" "\n1:\n\t" ) : "=a" ( status ) : "a" ( 0x4200 ), "d" ( drive ), "S" ( __from_data16 ( &eltorito_address ) ) ); if ( status ) { DBG ( "INT13 drive %02x could not read El Torito boot image " "(status %04x)\n", drive, status ); return -EIO; } return 0; } /** * Hook INT 13 SAN device * * @v drive Drive number * @v uris List of URIs * @v count Number of URIs * @v flags Flags * @ret drive Drive number, or negative error * * Registers the drive with the INT 13 emulation subsystem, and hooks * the INT 13 interrupt vector (if not already hooked). */ unsigned int ventoy_int13_hook (ventoy_chain_head *chain) { unsigned int blocks; unsigned int blocks_per_cyl; unsigned int natural_drive; struct int13_data *int13; /* We simulate a cdrom, so no need to sync hd drive number */ //int13_sync_num_drives(); /* hook will copy num_drives to dl when int13 08 was called, so must initialize it's value */ get_real(num_drives, BDA_SEG, BDA_NUM_DRIVES); //natural_drive = num_drives | 0x80; natural_drive = 0xE0; /* just set a cdrom drive number 224 */ if (chain->disk_drive >= 0x80 && chain->drive_map >= 0x80) { g_drive_map1 = chain->disk_drive; g_drive_map2 = chain->drive_map; } /* a fake sandev */ g_sandev = zalloc(sizeof(struct san_device) + sizeof(struct int13_data)); g_sandev->priv = int13 = (struct int13_data *)(g_sandev + 1); g_sandev->drive = int13->natural_drive = natural_drive; g_sandev->is_cdrom = 1; g_sandev->blksize_shift = 2; g_sandev->capacity.blksize = 512; g_sandev->capacity.blocks = chain->virt_img_size_in_bytes / 512; g_sandev->exdrive = chain->disk_drive; int13->boot_catalog = chain->boot_catalog; memcpy(g_sandev->boot_catalog_sector, chain->boot_catalog_sector, sizeof(chain->boot_catalog_sector)); /* Apply guesses if no geometry already specified */ if ( ! int13->heads ) int13->heads = 255; if ( ! int13->sectors_per_track ) int13->sectors_per_track = 63; if ( ! int13->cylinders ) { /* Avoid attempting a 64-bit divide on a 32-bit system */ blocks = int13_capacity32 ( g_sandev ); blocks_per_cyl = ( int13->heads * int13->sectors_per_track ); int13->cylinders = ( blocks / blocks_per_cyl ); if ( int13->cylinders > 1024 ) int13->cylinders = 1024; } /* Hook INT 13 vector if not already hooked */ int13_hook_vector(); /* Update BIOS drive count */ //int13_sync_num_drives(); return natural_drive; } static uint8_t __bss16_array ( xbftab, [512 + 128]) __attribute__ (( aligned ( 16 ) )); #define xbftab __use_data16 ( xbftab ) void * ventoy_get_runtime_addr(void) { return (void *)user_to_phys((userptr_t)(&xbftab), 0); } /** * Attempt to boot from an INT 13 drive * * @v drive Drive number * @v filename Filename (or NULL to use default) * @ret rc Return status code * * This boots from the specified INT 13 drive by loading the Master * Boot Record to 0000:7c00 and jumping to it. INT 18 is hooked to * capture an attempt by the MBR to boot the next device. (This is * the closest thing to a return path from an MBR). * * Note that this function can never return success, by definition. */ int ventoy_int13_boot ( unsigned int drive, void *imginfo, const char *cmdline) { //struct memory_map memmap; int rc; int headlen; struct segoff address; struct acpi_header *acpi = NULL; struct ibft_table *ibft = NULL; /* Look for a usable boot sector */ if ( ( ( rc = int13_load_eltorito ( drive, &address ) ) != 0 ) && ( ( rc = int13_load_mbr ( drive, &address ) ) != 0 )) return rc; if (imginfo) { if (strstr(cmdline, "ibft")) { headlen = 80; ibft = (struct ibft_table *)(&xbftab); acpi = &(ibft->acpi); memset(ibft, 0, headlen); acpi->signature = IBFT_SIG; acpi->length = headlen + sizeof(ventoy_os_param); acpi->revision = 1; strncpy(acpi->oem_id, "ventoy", sizeof(acpi->oem_id)); strncpy(acpi->oem_table_id, "runtime", sizeof(acpi->oem_table_id)); memcpy((uint8_t *)ibft + headlen, imginfo, sizeof(ventoy_os_param)); acpi_fix_checksum(acpi); } else { memcpy((&xbftab), imginfo, sizeof(ventoy_os_param)); } } /* Dump out memory map prior to boot, if memmap debugging is * enabled. Not required for program flow, but we have so * many problems that turn out to be memory-map related that * it's worth doing. */ //get_memmap ( &memmap ); DBGC(g_sandev, "start to boot ...\n"); /* Jump to boot sector */ if ( ( rc = call_bootsector ( address.segment, address.offset, drive ) ) != 0 ) { return rc; } return -ECANCELED; /* -EIMPOSSIBLE */ }