diff options
Diffstat (limited to 'qemu/roms/ipxe/src/arch/i386/interface/pcbios/int13.c')
| -rw-r--r-- | qemu/roms/ipxe/src/arch/i386/interface/pcbios/int13.c | 1993 |
1 files changed, 0 insertions, 1993 deletions
diff --git a/qemu/roms/ipxe/src/arch/i386/interface/pcbios/int13.c b/qemu/roms/ipxe/src/arch/i386/interface/pcbios/int13.c deleted file mode 100644 index f0450da90..000000000 --- a/qemu/roms/ipxe/src/arch/i386/interface/pcbios/int13.c +++ /dev/null @@ -1,1993 +0,0 @@ -/* - * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>. - * - * 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 <stdint.h> -#include <stdlib.h> -#include <limits.h> -#include <byteswap.h> -#include <errno.h> -#include <assert.h> -#include <ipxe/list.h> -#include <ipxe/blockdev.h> -#include <ipxe/io.h> -#include <ipxe/open.h> -#include <ipxe/uri.h> -#include <ipxe/process.h> -#include <ipxe/xfer.h> -#include <ipxe/retry.h> -#include <ipxe/timer.h> -#include <ipxe/acpi.h> -#include <ipxe/sanboot.h> -#include <ipxe/device.h> -#include <ipxe/pci.h> -#include <ipxe/iso9660.h> -#include <ipxe/eltorito.h> -#include <realmode.h> -#include <bios.h> -#include <biosint.h> -#include <bootsector.h> -#include <int13.h> - -/** @file - * - * INT 13 emulation - * - * This module provides a mechanism for exporting block devices via - * the BIOS INT 13 disk interrupt interface. - * - */ - -/** - * Overall timeout for INT 13 commands (independent of underlying device - * - * Underlying devices should ideally never become totally stuck. - * However, if they do, then the INT 13 mechanism provides no means - * for the caller to cancel the operation, and the machine appears to - * hang. Use an overall timeout for all commands to avoid this - * problem and bounce timeout failures to the caller. - */ -#define INT13_COMMAND_TIMEOUT ( 15 * TICKS_PER_SEC ) - -/** An INT 13 emulated drive */ -struct int13_drive { - /** Reference count */ - struct refcnt refcnt; - /** List of all registered drives */ - struct list_head list; - - /** Block device URI */ - struct uri *uri; - /** Underlying block device interface */ - struct interface block; - - /** BIOS in-use drive number (0x00-0xff) */ - unsigned int drive; - /** 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; - - /** Block device capacity */ - struct block_device_capacity capacity; - /** INT 13 emulated blocksize shift - * - * To allow for emulation of CD-ROM access, this represents - * the left-shift required to translate from INT 13 blocks to - * underlying blocks. - */ - unsigned int blksize_shift; - - /** 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; - - /** Drive is a CD-ROM */ - int is_cdrom; - /** Address of El Torito boot catalog (if any) */ - unsigned int boot_catalog; - - /** Underlying device status, if in error */ - int block_rc; - /** 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 ) - -/** List of registered emulated drives */ -static LIST_HEAD ( int13s ); - -/** - * 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 ) - -/** - * Calculate INT 13 drive sector size - * - * @v int13 Emulated drive - * @ret blksize Sector size - */ -static inline size_t int13_blksize ( struct int13_drive *int13 ) { - return ( int13->capacity.blksize << int13->blksize_shift ); -} - -/** - * Calculate INT 13 drive capacity - * - * @v int13 Emulated drive - * @ret blocks Number of blocks - */ -static inline uint64_t int13_capacity ( struct int13_drive *int13 ) { - return ( int13->capacity.blocks >> int13->blksize_shift ); -} - -/** - * Calculate INT 13 drive capacity (limited to 32 bits) - * - * @v int13 Emulated drive - * @ret blocks Number of blocks - */ -static inline uint32_t int13_capacity32 ( struct int13_drive *int13 ) { - uint64_t capacity = int13_capacity ( int13 ); - return ( ( capacity <= 0xffffffffUL ) ? capacity : 0xffffffff ); -} - -/** - * Test if INT 13 drive is a floppy disk drive - * - * @v int13 Emulated drive - * @ret is_fdd Emulated drive is a floppy disk - */ -static inline int int13_is_fdd ( struct int13_drive *int13 ) { - return ( ! ( int13->drive & 0x80 ) ); -} - -/** An INT 13 command */ -struct int13_command { - /** Status */ - int rc; - /** INT 13 drive */ - struct int13_drive *int13; - /** Underlying block device interface */ - struct interface block; - /** Command timeout timer */ - struct retry_timer timer; -}; - -/** - * Record INT 13 drive capacity - * - * @v command INT 13 command - * @v capacity Block device capacity - */ -static void int13_command_capacity ( struct int13_command *command, - struct block_device_capacity *capacity ) { - memcpy ( &command->int13->capacity, capacity, - sizeof ( command->int13->capacity ) ); -} - -/** - * Close INT 13 command - * - * @v command INT 13 command - * @v rc Reason for close - */ -static void int13_command_close ( struct int13_command *command, int rc ) { - intf_restart ( &command->block, rc ); - stop_timer ( &command->timer ); - command->rc = rc; -} - -/** - * Handle INT 13 command timer expiry - * - * @v timer Timer - */ -static void int13_command_expired ( struct retry_timer *timer, - int over __unused ) { - struct int13_command *command = - container_of ( timer, struct int13_command, timer ); - - int13_command_close ( command, -ETIMEDOUT ); -} - -/** INT 13 command interface operations */ -static struct interface_operation int13_command_op[] = { - INTF_OP ( intf_close, struct int13_command *, int13_command_close ), - INTF_OP ( block_capacity, struct int13_command *, - int13_command_capacity ), -}; - -/** INT 13 command interface descriptor */ -static struct interface_descriptor int13_command_desc = - INTF_DESC ( struct int13_command, block, int13_command_op ); - -/** - * Open (or reopen) INT 13 emulated drive underlying block device - * - * @v int13 Emulated drive - * @ret rc Return status code - */ -static int int13_reopen_block ( struct int13_drive *int13 ) { - int rc; - - /* Close any existing block device */ - intf_restart ( &int13->block, -ECONNRESET ); - - /* Open block device */ - if ( ( rc = xfer_open_uri ( &int13->block, int13->uri ) ) != 0 ) { - DBGC ( int13, "INT13 drive %02x could not reopen block " - "device: %s\n", int13->drive, strerror ( rc ) ); - int13->block_rc = rc; - return rc; - } - - /* Clear block device error status */ - int13->block_rc = 0; - - return 0; -} - -/** - * Prepare to issue INT 13 command - * - * @v command INT 13 command - * @v int13 Emulated drive - * @ret rc Return status code - */ -static int int13_command_start ( struct int13_command *command, - struct int13_drive *int13 ) { - int rc; - - /* Sanity check */ - assert ( command->int13 == NULL ); - assert ( ! timer_running ( &command->timer ) ); - - /* Reopen block device if necessary */ - if ( ( int13->block_rc != 0 ) && - ( ( rc = int13_reopen_block ( int13 ) ) != 0 ) ) - return rc; - - /* Initialise command */ - command->rc = -EINPROGRESS; - command->int13 = int13; - start_timer_fixed ( &command->timer, INT13_COMMAND_TIMEOUT ); - - /* Wait for block control interface to become ready */ - while ( ( command->rc == -EINPROGRESS ) && - ( xfer_window ( &int13->block ) == 0 ) ) { - step(); - } - - return ( ( command->rc == -EINPROGRESS ) ? - int13->block_rc : command->rc ); -} - -/** - * Wait for INT 13 command to complete - * - * @v command INT 13 command - * @ret rc Return status code - */ -static int int13_command_wait ( struct int13_command *command ) { - - /* Sanity check */ - assert ( timer_running ( &command->timer ) ); - - /* Wait for command to complete */ - while ( command->rc == -EINPROGRESS ) - step(); - - assert ( ! timer_running ( &command->timer ) ); - return command->rc; -} - -/** - * Terminate INT 13 command - * - * @v command INT 13 command - */ -static void int13_command_stop ( struct int13_command *command ) { - stop_timer ( &command->timer ); - command->int13 = NULL; -} - -/** The single active INT 13 command */ -static struct int13_command int13_command = { - .block = INTF_INIT ( int13_command_desc ), - .timer = TIMER_INIT ( int13_command_expired ), -}; - -/** - * Read from or write to INT 13 drive - * - * @v int13 Emulated drive - * @v lba Starting logical block address - * @v count Number of logical blocks - * @v buffer Data buffer - * @v block_rw Block read/write method - * @ret rc Return status code - */ -static int int13_rw ( struct int13_drive *int13, uint64_t lba, - unsigned int count, userptr_t buffer, - int ( * block_rw ) ( struct interface *control, - struct interface *data, - uint64_t lba, unsigned int count, - userptr_t buffer, size_t len ) ) { - struct int13_command *command = &int13_command; - unsigned int frag_count; - size_t frag_len; - int rc; - - /* Translate to underlying blocksize */ - lba <<= int13->blksize_shift; - count <<= int13->blksize_shift; - - while ( count ) { - - /* Determine fragment length */ - frag_count = count; - if ( frag_count > int13->capacity.max_count ) - frag_count = int13->capacity.max_count; - frag_len = ( int13->capacity.blksize * frag_count ); - - /* Issue command */ - if ( ( ( rc = int13_command_start ( command, int13 ) ) != 0 ) || - ( ( rc = block_rw ( &int13->block, &command->block, lba, - frag_count, buffer, - frag_len ) ) != 0 ) || - ( ( rc = int13_command_wait ( command ) ) != 0 ) ) { - int13_command_stop ( command ); - return rc; - } - int13_command_stop ( command ); - - /* Move to next fragment */ - lba += frag_count; - count -= frag_count; - buffer = userptr_add ( buffer, frag_len ); - } - - return 0; -} - -/** - * Read INT 13 drive capacity - * - * @v int13 Emulated drive - * @ret rc Return status code - */ -static int int13_read_capacity ( struct int13_drive *int13 ) { - struct int13_command *command = &int13_command; - int rc; - - /* Issue command */ - if ( ( ( rc = int13_command_start ( command, int13 ) ) != 0 ) || - ( ( rc = block_read_capacity ( &int13->block, - &command->block ) ) != 0 ) || - ( ( rc = int13_command_wait ( command ) ) != 0 ) ) { - int13_command_stop ( command ); - return rc; - } - - int13_command_stop ( command ); - return 0; -} - -/** - * Parse ISO9660 parameters - * - * @v int13 Emulated drive - * @v scratch Scratch area for single-sector reads - * @ret rc Return status code - * - * Reads and parses ISO9660 parameters, if present. - */ -static int int13_parse_iso9660 ( struct int13_drive *int13, void *scratch ) { - static const struct iso9660_primary_descriptor_fixed primary_check = { - .type = ISO9660_TYPE_PRIMARY, - .id = ISO9660_ID, - }; - struct iso9660_primary_descriptor *primary = scratch; - static const struct eltorito_descriptor_fixed boot_check = { - .type = ISO9660_TYPE_BOOT, - .id = ISO9660_ID, - .version = 1, - .system_id = "EL TORITO SPECIFICATION", - }; - struct eltorito_descriptor *boot = scratch; - unsigned int blksize; - unsigned int blksize_shift; - int rc; - - /* Calculate required blocksize shift */ - blksize = int13_blksize ( int13 ); - blksize_shift = 0; - while ( blksize < ISO9660_BLKSIZE ) { - blksize <<= 1; - blksize_shift++; - } - if ( blksize > ISO9660_BLKSIZE ) { - /* Do nothing if the blksize is invalid for CD-ROM access */ - return 0; - } - - /* Read primary volume descriptor */ - if ( ( rc = int13_rw ( int13, - ( ISO9660_PRIMARY_LBA << blksize_shift ), 1, - virt_to_user ( primary ), block_read ) ) != 0 ){ - DBGC ( int13, "INT13 drive %02x could not read ISO9660 " - "primary volume descriptor: %s\n", - int13->drive, strerror ( rc ) ); - return rc; - } - - /* Do nothing unless this is an ISO image */ - if ( memcmp ( primary, &primary_check, sizeof ( primary_check ) ) != 0 ) - return 0; - DBGC ( int13, "INT13 drive %02x contains an ISO9660 filesystem; " - "treating as CD-ROM\n", int13->drive ); - int13->is_cdrom = 1; - - /* Read boot record volume descriptor */ - if ( ( rc = int13_rw ( int13, - ( ELTORITO_LBA << blksize_shift ), 1, - virt_to_user ( boot ), block_read ) ) != 0 ) { - DBGC ( int13, "INT13 drive %02x could not read El Torito boot " - "record volume descriptor: %s\n", - int13->drive, strerror ( rc ) ); - return rc; - } - - /* Check for an El Torito boot catalog */ - if ( memcmp ( boot, &boot_check, sizeof ( boot_check ) ) == 0 ) { - int13->boot_catalog = boot->sector; - DBGC ( int13, "INT13 drive %02x has an El Torito boot catalog " - "at LBA %08x\n", int13->drive, int13->boot_catalog ); - } else { - DBGC ( int13, "INT13 drive %02x has no El Torito boot " - "catalog\n", int13->drive ); - } - - /* Configure drive for no-emulation CD-ROM access */ - int13->blksize_shift += blksize_shift; - - return 0; -} - -/** - * Guess INT 13 hard disk drive geometry - * - * @v int13 Emulated drive - * @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 int13_drive *int13, void *scratch, - unsigned int *heads, - unsigned int *sectors ) { - struct master_boot_record *mbr = scratch; - struct partition_table_entry *partition; - unsigned int i; - int rc; - - /* Default guess is xx/255/63 */ - *heads = 255; - *sectors = 63; - - /* Read partition table */ - if ( ( rc = int13_rw ( int13, 0, 1, virt_to_user ( mbr ), - block_read ) ) != 0 ) { - DBGC ( int13, "INT13 drive %02x could not read " - "partition table to guess geometry: %s\n", - int13->drive, strerror ( rc ) ); - return rc; - } - DBGC2 ( int13, "INT13 drive %02x has MBR:\n", int13->drive ); - DBGC2_HDA ( int13, 0, mbr, sizeof ( *mbr ) ); - DBGC ( int13, "INT13 drive %02x has signature %08x\n", - int13->drive, mbr->signature ); - - /* Scan through partition table and modify guesses for - * heads and sectors_per_track if we find any used - * partitions. - */ - for ( i = 0 ; i < 4 ; i++ ) { - partition = &mbr->partitions[i]; - if ( ! partition->type ) - continue; - *heads = ( PART_HEAD ( partition->chs_end ) + 1 ); - *sectors = PART_SECTOR ( partition->chs_end ); - DBGC ( int13, "INT13 drive %02x guessing C/H/S xx/%d/%d based " - "on partition %d\n", - int13->drive, *heads, *sectors, ( i + 1 ) ); - } - - 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 int13 Emulated drive - * @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 int13_drive *int13, - unsigned int *heads, - unsigned int *sectors ) { - unsigned int blocks = int13_capacity ( int13 ); - 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 ( int13, "INT13 drive %02x guessing C/H/S " - "%d/%d/%d based on size %dK\n", int13->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 ( int13, "INT13 drive %02x guessing C/H/S xx/%d/%d based on size " - "%dK\n", int13->drive, *heads, *sectors, ( blocks / 2 ) ); - return 0; -} - -/** - * Guess INT 13 drive geometry - * - * @v int13 Emulated drive - * @v scratch Scratch area for single-sector reads - * @ret rc Return status code - */ -static int int13_guess_geometry ( struct int13_drive *int13, void *scratch ) { - unsigned int guessed_heads; - unsigned int guessed_sectors; - unsigned int blocks; - unsigned int blocks_per_cyl; - int rc; - - /* Don't even try when the blksize is invalid for C/H/S access */ - if ( int13_blksize ( int13 ) != INT13_BLKSIZE ) - return 0; - - /* Guess geometry according to drive type */ - if ( int13_is_fdd ( int13 ) ) { - if ( ( rc = int13_guess_geometry_fdd ( int13, &guessed_heads, - &guessed_sectors )) != 0) - return rc; - } else { - if ( ( rc = int13_guess_geometry_hdd ( int13, 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 ( int13 ); - 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; -} - -/** - * Update BIOS drive count - */ -static void int13_sync_num_drives ( void ) { - struct int13_drive *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 emulated drives */ - list_for_each_entry ( int13, &int13s, list ) { - counter = ( int13_is_fdd ( int13 ) ? &num_fdds : &num_drives ); - max_drive = int13->drive; - if ( max_drive < int13->natural_drive ) - max_drive = int13->natural_drive; - required = ( ( max_drive & 0x7f ) + 1 ); - if ( *counter < required ) { - *counter = required; - DBGC ( int13, "INT13 drive %02x added to drive count: " - "%d HDDs, %d FDDs\n", - int13->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 - */ -static 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 int13 Emulated drive - * @ret status Status code - */ -static int int13_reset ( struct int13_drive *int13, - struct i386_all_regs *ix86 __unused ) { - int rc; - - DBGC2 ( int13, "Reset drive\n" ); - - /* Reopen underlying block device */ - if ( ( rc = int13_reopen_block ( int13 ) ) != 0 ) - return -INT13_STATUS_RESET_FAILED; - - /* Check that block device is functional */ - if ( ( rc = int13_read_capacity ( int13 ) ) != 0 ) - return -INT13_STATUS_RESET_FAILED; - - return 0; -} - -/** - * INT 13, 01 - Get status of last operation - * - * @v int13 Emulated drive - * @ret status Status code - */ -static int int13_get_last_status ( struct int13_drive *int13, - struct i386_all_regs *ix86 __unused ) { - DBGC2 ( int13, "Get status of last operation\n" ); - return int13->last_status; -} - -/** - * Read / write sectors - * - * @v int13 Emulated drive - * @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 block_rw Block read/write method - * @ret status Status code - * @ret al Number of sectors read or written - */ -static int int13_rw_sectors ( struct int13_drive *int13, - struct i386_all_regs *ix86, - int ( * block_rw ) ( struct interface *control, - struct interface *data, - uint64_t lba, - unsigned int count, - userptr_t buffer, - size_t len ) ) { - unsigned int cylinder, head, sector; - unsigned long lba; - unsigned int count; - userptr_t buffer; - int rc; - - /* Validate blocksize */ - if ( int13_blksize ( int13 ) != INT13_BLKSIZE ) { - DBGC ( int13, "\nINT 13 drive %02x invalid blocksize (%zd) " - "for non-extended read/write\n", - int13->drive, int13_blksize ( int13 ) ); - 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 ( int13, "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 ( int13, "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 = int13_rw ( int13, lba, count, buffer, block_rw ) ) != 0 ) { - DBGC ( int13, "INT13 drive %02x I/O failed: %s\n", - int13->drive, strerror ( rc ) ); - return -INT13_STATUS_READ_ERROR; - } - - return 0; -} - -/** - * INT 13, 02 - Read sectors - * - * @v int13 Emulated drive - * @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 int13_drive *int13, - struct i386_all_regs *ix86 ) { - DBGC2 ( int13, "Read: " ); - return int13_rw_sectors ( int13, ix86, block_read ); -} - -/** - * INT 13, 03 - Write sectors - * - * @v int13 Emulated drive - * @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 int13_drive *int13, - struct i386_all_regs *ix86 ) { - DBGC2 ( int13, "Write: " ); - return int13_rw_sectors ( int13, ix86, block_write ); -} - -/** - * INT 13, 08 - Get drive parameters - * - * @v int13 Emulated drive - * @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 int13_drive *int13, - struct i386_all_regs *ix86 ) { - unsigned int max_cylinder = int13->cylinders - 1; - unsigned int max_head = int13->heads - 1; - unsigned int max_sector = int13->sectors_per_track; /* sic */ - - DBGC2 ( int13, "Get drive parameters\n" ); - - /* Validate blocksize */ - if ( int13_blksize ( int13 ) != INT13_BLKSIZE ) { - DBGC ( int13, "\nINT 13 drive %02x invalid blocksize (%zd) " - "for non-extended parameters\n", - int13->drive, int13_blksize ( int13 ) ); - 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 ( int13 ) ? num_fdds : num_drives ); - - /* Floppy-specific parameters */ - if ( int13_is_fdd ( int13 ) ) { - 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 int13 Emulated drive - * @ret ah Type code - * @ret cx:dx Sector count - * @ret status Status code / disk type - */ -static int int13_get_disk_type ( struct int13_drive *int13, - struct i386_all_regs *ix86 ) { - uint32_t blocks; - - DBGC2 ( int13, "Get disk type\n" ); - - if ( int13_is_fdd ( int13 ) ) { - return INT13_DISK_TYPE_FDD; - } else { - blocks = int13_capacity32 ( int13 ); - ix86->regs.cx = ( blocks >> 16 ); - ix86->regs.dx = ( blocks & 0xffff ); - return INT13_DISK_TYPE_HDD; - } -} - -/** - * INT 13, 41 - Extensions installation check - * - * @v int13 Emulated drive - * @v bx 0x55aa - * @ret bx 0xaa55 - * @ret cx Extensions API support bitmap - * @ret status Status code / API version - */ -static int int13_extension_check ( struct int13_drive *int13 __unused, - struct i386_all_regs *ix86 ) { - if ( ix86->regs.bx == 0x55aa ) { - DBGC2 ( int13, "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 int13 Emulated drive - * @v ds:si Disk address packet - * @v block_rw Block read/write method - * @ret status Status code - */ -static int int13_extended_rw ( struct int13_drive *int13, - struct i386_all_regs *ix86, - int ( * block_rw ) ( struct interface *control, - struct interface *data, - uint64_t lba, - unsigned int count, - userptr_t buffer, - size_t len ) ) { - 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 ( int13 ) ) - 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 ( int13, "<invalid buffer size %#02x\n>\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 ( int13, "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 ( int13, "%08llx", - ( ( unsigned long long ) addr.buffer_phys ) ); - } else { - buffer = real_to_user ( addr.buffer.segment, - addr.buffer.offset ); - DBGC2 ( int13, "%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 ( int13, " <invalid count %#02x>\n", addr.count ); - return -INT13_STATUS_INVALID; - } - DBGC2 ( int13, " (count %ld)\n", count ); - - /* Read from / write to block device */ - if ( ( rc = int13_rw ( int13, lba, count, buffer, block_rw ) ) != 0 ) { - DBGC ( int13, "INT13 drive %02x extended I/O failed: %s\n", - int13->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; - } - - return 0; -} - -/** - * INT 13, 42 - Extended read - * - * @v int13 Emulated drive - * @v ds:si Disk address packet - * @ret status Status code - */ -static int int13_extended_read ( struct int13_drive *int13, - struct i386_all_regs *ix86 ) { - DBGC2 ( int13, "Extended read: " ); - return int13_extended_rw ( int13, ix86, block_read ); -} - -/** - * INT 13, 43 - Extended write - * - * @v int13 Emulated drive - * @v ds:si Disk address packet - * @ret status Status code - */ -static int int13_extended_write ( struct int13_drive *int13, - struct i386_all_regs *ix86 ) { - DBGC2 ( int13, "Extended write: " ); - return int13_extended_rw ( int13, ix86, block_write ); -} - -/** - * INT 13, 44 - Verify sectors - * - * @v int13 Emulated drive - * @v ds:si Disk address packet - * @ret status Status code - */ -static int int13_extended_verify ( struct int13_drive *int13, - 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 ( int13, "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 int13 Emulated drive - * @v ds:si Disk address packet - * @ret status Status code - */ -static int int13_extended_seek ( struct int13_drive *int13, - 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 ( int13, "Seek: LBA %08llx (count %ld)\n", - ( ( unsigned long long ) lba ), count ); - } - - /* Ignore and return success */ - return 0; -} - -/** - * Build device path information - * - * @v int13 Emulated drive - * @v dpi Device path information - * @ret rc Return status code - */ -static int int13_device_path_info ( struct int13_drive *int13, - struct edd_device_path_information *dpi ) { - struct device *device; - struct device_description *desc; - unsigned int i; - uint8_t sum = 0; - int rc; - - /* Reopen block device if necessary */ - if ( ( int13->block_rc != 0 ) && - ( ( rc = int13_reopen_block ( int13 ) ) != 0 ) ) - return rc; - - /* Get underlying hardware device */ - device = identify_device ( &int13->block ); - if ( ! device ) { - DBGC ( int13, "INT13 drive %02x cannot identify hardware " - "device\n", int13->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 ( int13, "INT13 drive %02x unrecognised bus type %d\n", - int13->drive, desc->bus_type ); - return -ENOTSUP; - } - - /* Get EDD block device description */ - if ( ( rc = edd_describe ( &int13->block, &dpi->interface_type, - &dpi->device_path ) ) != 0 ) { - DBGC ( int13, "INT13 drive %02x cannot identify block device: " - "%s\n", int13->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 int13 Emulated drive - * @v ds:si Drive parameter table - * @ret status Status code - */ -static int int13_get_extended_parameters ( struct int13_drive *int13, - struct i386_all_regs *ix86 ) { - 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 ( int13, "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 ) && - ( int13_capacity ( int13 ) <= 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 = int13_capacity ( int13 ); - params.sector_size = int13_blksize ( int13 ); - memset ( ¶ms.dpte, 0xff, sizeof ( params.dpte ) ); - if ( ( rc = int13_device_path_info ( int13, ¶ms.dpi ) ) != 0 ) { - DBGC ( int13, "INT13 drive %02x could not provide device " - "path information: %s\n", - int13->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 ( int13, "INT 13 drive %02x described using extended " - "parameters:\n", int13->drive ); - address.segment = ix86->segs.ds; - address.offset = ix86->regs.si; - DBGC_HDA ( int13, 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 int13 Emulated drive - * @v ds:si Specification packet - * @ret status Status code - */ -static int int13_cdrom_status_terminate ( struct int13_drive *int13, - struct i386_all_regs *ix86 ) { - struct int13_cdrom_specification specification; - - DBGC2 ( int13, "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 ( ! int13->is_cdrom ) { - DBGC ( int13, "INT13 drive %02x is not a CD-ROM\n", - int13->drive ); - return -INT13_STATUS_INVALID; - } - - /* Build specification packet */ - memset ( &specification, 0, sizeof ( specification ) ); - specification.size = sizeof ( specification ); - specification.drive = int13->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 int13 Emulated drive - * @v ds:si Command packet - * @ret status Status code - */ -static int int13_cdrom_read_boot_catalog ( struct int13_drive *int13, - struct i386_all_regs *ix86 ) { - struct int13_cdrom_boot_catalog_command command; - int rc; - - /* Read parameters from command packet */ - copy_from_real ( &command, ix86->segs.ds, ix86->regs.si, - sizeof ( command ) ); - DBGC2 ( int13, "Read CD-ROM boot catalog to %08x\n", command.buffer ); - - /* Fail if we have no boot catalog */ - if ( ! int13->boot_catalog ) { - DBGC ( int13, "INT13 drive %02x has no boot catalog\n", - int13->drive ); - return -INT13_STATUS_INVALID; - } - - /* Read from boot catalog */ - if ( ( rc = int13_rw ( int13, ( int13->boot_catalog + command.start ), - command.count, phys_to_user ( command.buffer ), - block_read ) ) != 0 ) { - DBGC ( int13, "INT13 drive %02x could not read boot catalog: " - "%s\n", int13->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 int13_drive *int13; - int status; - - /* Check BIOS hasn't killed off our drive */ - int13_check_num_drives(); - - list_for_each_entry ( int13, &int13s, list ) { - - if ( bios_drive != int13->drive ) { - /* Remap any accesses to this drive's natural number */ - if ( bios_drive == int13->natural_drive ) { - DBGC2 ( int13, "INT13,%02x (%02x) remapped to " - "(%02x)\n", ix86->regs.ah, - bios_drive, int13->drive ); - ix86->regs.dl = int13->drive; - return; - } else if ( ( ( bios_drive & 0x7f ) == 0x7f ) && - ( command == INT13_CDROM_STATUS_TERMINATE ) - && int13->is_cdrom ) { - /* Catch non-drive-specific CD-ROM calls */ - } else { - continue; - } - } - - DBGC2 ( int13, "INT13,%02x (%02x): ", - ix86->regs.ah, bios_drive ); - - switch ( command ) { - case INT13_RESET: - status = int13_reset ( int13, ix86 ); - break; - case INT13_GET_LAST_STATUS: - status = int13_get_last_status ( int13, ix86 ); - break; - case INT13_READ_SECTORS: - status = int13_read_sectors ( int13, ix86 ); - break; - case INT13_WRITE_SECTORS: - status = int13_write_sectors ( int13, ix86 ); - break; - case INT13_GET_PARAMETERS: - status = int13_get_parameters ( int13, ix86 ); - break; - case INT13_GET_DISK_TYPE: - status = int13_get_disk_type ( int13, ix86 ); - break; - case INT13_EXTENSION_CHECK: - status = int13_extension_check ( int13, ix86 ); - break; - case INT13_EXTENDED_READ: - status = int13_extended_read ( int13, ix86 ); - break; - case INT13_EXTENDED_WRITE: - status = int13_extended_write ( int13, ix86 ); - break; - case INT13_EXTENDED_VERIFY: - status = int13_extended_verify ( int13, ix86 ); - break; - case INT13_EXTENDED_SEEK: - status = int13_extended_seek ( int13, ix86 ); - break; - case INT13_GET_EXTENDED_PARAMETERS: - status = int13_get_extended_parameters ( int13, ix86 ); - break; - case INT13_CDROM_STATUS_TERMINATE: - status = int13_cdrom_status_terminate ( int13, ix86 ); - break; - case INT13_CDROM_READ_BOOT_CATALOG: - status = int13_cdrom_read_boot_catalog ( int13, ix86 ); - break; - default: - DBGC2 ( int13, "*** 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 ( int13, "INT13,%02x (%02x) failed with status " - "%02x\n", ix86->regs.ah, int13->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" - "pushl %0\n\t" - "pushw %%cs\n\t" - "call prot_call\n\t" - /* 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" ) - : : "i" ( int13 ) ); - - hook_bios_interrupt ( 0x13, ( unsigned int ) int13_wrapper, - &int13_vector ); -} - -/** - * Unhook INT 13 handler - */ -static void int13_unhook_vector ( void ) { - unhook_bios_interrupt ( 0x13, ( unsigned int ) int13_wrapper, - &int13_vector ); -} - -/** - * Check INT13 emulated drive flow control window - * - * @v int13 Emulated drive - */ -static size_t int13_block_window ( struct int13_drive *int13 __unused ) { - - /* We are never ready to receive data via this interface. - * This prevents objects that support both block and stream - * interfaces from attempting to send us stream data. - */ - return 0; -} - -/** - * Handle INT 13 emulated drive underlying block device closing - * - * @v int13 Emulated drive - * @v rc Reason for close - */ -static void int13_block_close ( struct int13_drive *int13, int rc ) { - - /* Any closing is an error from our point of view */ - if ( rc == 0 ) - rc = -ENOTCONN; - - DBGC ( int13, "INT13 drive %02x went away: %s\n", - int13->drive, strerror ( rc ) ); - - /* Record block device error code */ - int13->block_rc = rc; - - /* Shut down interfaces */ - intf_restart ( &int13->block, rc ); -} - -/** INT 13 drive interface operations */ -static struct interface_operation int13_block_op[] = { - INTF_OP ( xfer_window, struct int13_drive *, int13_block_window ), - INTF_OP ( intf_close, struct int13_drive *, int13_block_close ), -}; - -/** INT 13 drive interface descriptor */ -static struct interface_descriptor int13_block_desc = - INTF_DESC ( struct int13_drive, block, int13_block_op ); - -/** - * Free INT 13 emulated drive - * - * @v refcnt Reference count - */ -static void int13_free ( struct refcnt *refcnt ) { - struct int13_drive *int13 = - container_of ( refcnt, struct int13_drive, refcnt ); - - uri_put ( int13->uri ); - free ( int13 ); -} - -/** - * Hook INT 13 emulated drive - * - * @v uri URI - * @v drive Drive number - * @ret rc Return status code - * - * Registers the drive with the INT 13 emulation subsystem, and hooks - * the INT 13 interrupt vector (if not already hooked). - */ -static int int13_hook ( struct uri *uri, unsigned int drive ) { - struct int13_drive *int13; - unsigned int natural_drive; - void *scratch; - int rc; - - /* Calculate natural drive number */ - int13_sync_num_drives(); - natural_drive = ( ( drive & 0x80 ) ? ( num_drives | 0x80 ) : num_fdds ); - - /* Check that drive number is not in use */ - list_for_each_entry ( int13, &int13s, list ) { - if ( int13->drive == drive ) { - rc = -EADDRINUSE; - goto err_in_use; - } - } - - /* Allocate and initialise structure */ - int13 = zalloc ( sizeof ( *int13 ) ); - if ( ! int13 ) { - rc = -ENOMEM; - goto err_zalloc; - } - ref_init ( &int13->refcnt, int13_free ); - intf_init ( &int13->block, &int13_block_desc, &int13->refcnt ); - int13->uri = uri_get ( uri ); - int13->drive = drive; - int13->natural_drive = natural_drive; - - /* Open block device interface */ - if ( ( rc = int13_reopen_block ( int13 ) ) != 0 ) - goto err_reopen_block; - - /* Read device capacity */ - if ( ( rc = int13_read_capacity ( int13 ) ) != 0 ) - goto err_read_capacity; - - /* Allocate scratch area */ - scratch = malloc ( int13_blksize ( int13 ) ); - if ( ! scratch ) - goto err_alloc_scratch; - - /* Parse parameters, if present */ - if ( ( rc = int13_parse_iso9660 ( int13, scratch ) ) != 0 ) - goto err_parse_iso9660; - - /* Give drive a default geometry */ - if ( ( rc = int13_guess_geometry ( int13, scratch ) ) != 0 ) - goto err_guess_geometry; - - DBGC ( int13, "INT13 drive %02x (naturally %02x) registered with C/H/S " - "geometry %d/%d/%d\n", int13->drive, int13->natural_drive, - int13->cylinders, int13->heads, int13->sectors_per_track ); - - /* Hook INT 13 vector if not already hooked */ - if ( list_empty ( &int13s ) ) { - int13_hook_vector(); - devices_get(); - } - - /* Add to list of emulated drives */ - list_add ( &int13->list, &int13s ); - - /* Update BIOS drive count */ - int13_sync_num_drives(); - - free ( scratch ); - return 0; - - err_guess_geometry: - err_parse_iso9660: - free ( scratch ); - err_alloc_scratch: - err_read_capacity: - err_reopen_block: - intf_shutdown ( &int13->block, rc ); - ref_put ( &int13->refcnt ); - err_zalloc: - err_in_use: - return rc; -} - -/** - * Find INT 13 emulated drive by drive number - * - * @v drive Drive number - * @ret int13 Emulated drive, or NULL - */ -static struct int13_drive * int13_find ( unsigned int drive ) { - struct int13_drive *int13; - - list_for_each_entry ( int13, &int13s, list ) { - if ( int13->drive == drive ) - return int13; - } - return NULL; -} - -/** - * Unhook INT 13 emulated drive - * - * @v drive Drive number - * - * Unregisters the drive from the INT 13 emulation subsystem. If this - * is the last emulated drive, the INT 13 vector is unhooked (if - * possible). - */ -static void int13_unhook ( unsigned int drive ) { - struct int13_drive *int13; - - /* Find drive */ - int13 = int13_find ( drive ); - if ( ! int13 ) { - DBG ( "INT13 cannot find emulated drive %02x\n", drive ); - return; - } - - /* Shut down interfaces */ - intf_shutdown ( &int13->block, 0 ); - - /* Remove from list of emulated drives */ - list_del ( &int13->list ); - - /* Should adjust BIOS drive count, but it's difficult - * to do so reliably. - */ - - DBGC ( int13, "INT13 drive %02x unregistered\n", int13->drive ); - - /* Unhook INT 13 vector if no more drives */ - if ( list_empty ( &int13s ) ) { - devices_put(); - int13_unhook_vector(); - } - - /* Drop list's reference to drive */ - ref_put ( &int13->refcnt ); -} - -/** - * 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 ) { - uint8_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 %02x)\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; - uint8_t status; - - /* 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 %02x)\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 %02x)\n", drive, status ); - return -EIO; - } - - return 0; -} - -/** - * Attempt to boot from an INT 13 drive - * - * @v drive Drive number - * @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. - */ -static int int13_boot ( unsigned int drive ) { - struct memory_map memmap; - struct segoff address; - int rc; - - /* Look for a usable boot sector */ - if ( ( ( rc = int13_load_mbr ( drive, &address ) ) != 0 ) && - ( ( rc = int13_load_eltorito ( drive, &address ) ) != 0 ) ) - return rc; - - /* 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 ); - - /* Jump to boot sector */ - if ( ( rc = call_bootsector ( address.segment, address.offset, - drive ) ) != 0 ) { - DBG ( "INT13 drive %02x boot returned: %s\n", - drive, strerror ( rc ) ); - return rc; - } - - return -ECANCELED; /* -EIMPOSSIBLE */ -} - -/** A boot firmware table generated by iPXE */ -union xbft_table { - /** ACPI header */ - struct acpi_description_header acpi; - /** Padding */ - char pad[768]; -}; - -/** The boot firmware table generated by iPXE */ -static union xbft_table __bss16 ( xbftab ) __attribute__ (( aligned ( 16 ) )); -#define xbftab __use_data16 ( xbftab ) - -/** - * Describe INT 13 emulated drive for SAN-booted operating system - * - * @v drive Drive number - * @ret rc Return status code - */ -static int int13_describe ( unsigned int drive ) { - struct int13_drive *int13; - struct segoff xbft_address; - int rc; - - /* Find drive */ - int13 = int13_find ( drive ); - if ( ! int13 ) { - DBG ( "INT13 cannot find emulated drive %02x\n", drive ); - return -ENODEV; - } - - /* Reopen block device if necessary */ - if ( ( int13->block_rc != 0 ) && - ( ( rc = int13_reopen_block ( int13 ) ) != 0 ) ) - return rc; - - /* Clear table */ - memset ( &xbftab, 0, sizeof ( xbftab ) ); - - /* Fill in common parameters */ - strncpy ( xbftab.acpi.oem_id, "FENSYS", - sizeof ( xbftab.acpi.oem_id ) ); - strncpy ( xbftab.acpi.oem_table_id, "iPXE", - sizeof ( xbftab.acpi.oem_table_id ) ); - - /* Fill in remaining parameters */ - if ( ( rc = acpi_describe ( &int13->block, &xbftab.acpi, - sizeof ( xbftab ) ) ) != 0 ) { - DBGC ( int13, "INT13 drive %02x could not create ACPI " - "description: %s\n", int13->drive, strerror ( rc ) ); - return rc; - } - - /* Fix up ACPI checksum */ - acpi_fix_checksum ( &xbftab.acpi ); - xbft_address.segment = rm_ds; - xbft_address.offset = __from_data16 ( &xbftab ); - DBGC ( int13, "INT13 drive %02x described using boot firmware " - "table:\n", int13->drive ); - DBGC_HDA ( int13, xbft_address, &xbftab, - le32_to_cpu ( xbftab.acpi.length ) ); - - return 0; -} - -PROVIDE_SANBOOT_INLINE ( pcbios, san_default_drive ); -PROVIDE_SANBOOT ( pcbios, san_hook, int13_hook ); -PROVIDE_SANBOOT ( pcbios, san_unhook, int13_unhook ); -PROVIDE_SANBOOT ( pcbios, san_boot, int13_boot ); -PROVIDE_SANBOOT ( pcbios, san_describe, int13_describe ); |