diff options
Diffstat (limited to 'src/arch/i386/interface/pcbios/int13.c')
| -rw-r--r-- | src/arch/i386/interface/pcbios/int13.c | 890 |
1 files changed, 696 insertions, 194 deletions
diff --git a/src/arch/i386/interface/pcbios/int13.c b/src/arch/i386/interface/pcbios/int13.c index f72dc5fa9..97110fde1 100644 --- a/src/arch/i386/interface/pcbios/int13.c +++ b/src/arch/i386/interface/pcbios/int13.c @@ -19,6 +19,7 @@ FILE_LICENCE ( GPL2_OR_LATER ); #include <stdint.h> +#include <stdlib.h> #include <limits.h> #include <byteswap.h> #include <errno.h> @@ -26,6 +27,14 @@ FILE_LICENCE ( GPL2_OR_LATER ); #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 <realmode.h> #include <bios.h> #include <biosint.h> @@ -41,6 +50,77 @@ FILE_LICENCE ( GPL2_OR_LATER ); * */ +/** + * 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 (0x80-0xff) */ + unsigned int drive; + /** BIOS natural drive number (0x80-0xff) + * + * 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; + + /** 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; + + /** 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 ) @@ -49,7 +129,7 @@ static struct segoff __text16 ( int13_vector ); extern void int13_wrapper ( void ); /** List of registered emulated drives */ -static LIST_HEAD ( drives ); +static LIST_HEAD ( int13s ); /** * Number of BIOS drives @@ -60,19 +140,309 @@ static LIST_HEAD ( drives ); */ static uint8_t num_drives; +/** 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 ); + +/** + * 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 ) { + + /* Sanity check */ + assert ( command->int13 == NULL ); + assert ( ! timer_running ( &command->timer ) ); + + /* 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; + + 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; +} + +/** + * Guess INT 13 drive geometry + * + * @v int13 Emulated drive + * @ret rc Return status code + * + * Guesses the drive geometry by inspecting the partition table. + */ +static int int13_guess_geometry ( struct int13_drive *int13 ) { + struct master_boot_record mbr; + struct partition_table_entry *partition; + unsigned int guessed_heads = 255; + unsigned int guessed_sectors_per_track = 63; + unsigned long blocks; + unsigned long blocks_per_cyl; + unsigned int i; + int rc; + + /* Don't even try when the blksize is invalid for C/H/S access */ + if ( int13->capacity.blksize != INT13_BLKSIZE ) + return 0; + + /* 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; + } + + /* 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; + guessed_heads = ( PART_HEAD ( partition->chs_end ) + 1 ); + guessed_sectors_per_track = PART_SECTOR ( partition->chs_end ); + DBGC ( int13, "INT13 drive %02x guessing C/H/S xx/%d/%d based " + "on partition %d\n", int13->drive, guessed_heads, + guessed_sectors_per_track, ( i + 1 ) ); + } + + /* 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_per_track; + if ( ! int13->cylinders ) { + /* Avoid attempting a 64-bit divide on a 32-bit system */ + blocks = ( ( int13->capacity.blocks <= ULONG_MAX ) ? + int13->capacity.blocks : ULONG_MAX ); + 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; +} + +/** + * 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; + + /* Read device capacity */ + if ( ( rc = int13_read_capacity ( int13 ) ) != 0 ) + return rc; + + return 0; +} + /** * Update BIOS drive count */ static void int13_set_num_drives ( void ) { - struct int13_drive *drive; + struct int13_drive *int13; /* Get current drive count */ get_real ( num_drives, BDA_SEG, BDA_NUM_DRIVES ); /* Ensure count is large enough to cover all of our emulated drives */ - list_for_each_entry ( drive, &drives, list ) { - if ( num_drives <= ( drive->drive & 0x7f ) ) - num_drives = ( ( drive->drive & 0x7f ) + 1 ); + list_for_each_entry ( int13, &int13s, list ) { + if ( num_drives <= ( int13->drive & 0x7f ) ) + num_drives = ( ( int13->drive & 0x7f ) + 1 ); } /* Update current drive count */ @@ -96,48 +466,56 @@ static void int13_check_num_drives ( void ) { /** * INT 13, 00 - Reset disk system * - * @v drive Emulated drive + * @v int13 Emulated drive * @ret status Status code */ -static int int13_reset ( struct int13_drive *drive __unused, +static int int13_reset ( struct int13_drive *int13, struct i386_all_regs *ix86 __unused ) { - DBG ( "Reset drive\n" ); + int rc; + + DBGC2 ( int13, "Reset drive\n" ); + + /* Reopen underlying block device */ + if ( ( rc = int13_reopen_block ( int13 ) ) != 0 ) + return -INT13_STATUS_RESET_FAILED; + return 0; } /** * INT 13, 01 - Get status of last operation * - * @v drive Emulated drive + * @v int13 Emulated drive * @ret status Status code */ -static int int13_get_last_status ( struct int13_drive *drive, +static int int13_get_last_status ( struct int13_drive *int13, struct i386_all_regs *ix86 __unused ) { - DBG ( "Get status of last operation\n" ); - return drive->last_status; + DBGC2 ( int13, "Get status of last operation\n" ); + return int13->last_status; } /** * Read / write sectors * - * @v drive Emulated drive + * @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 io Read / write method + * @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 *drive, +static int int13_rw_sectors ( struct int13_drive *int13, struct i386_all_regs *ix86, - int ( * io ) ( struct block_device *blockdev, - uint64_t block, - unsigned long count, - userptr_t buffer ) ) { - struct block_device *blockdev = drive->blockdev; + 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; @@ -145,30 +523,33 @@ static int int13_rw_sectors ( struct int13_drive *drive, int rc; /* Validate blocksize */ - if ( blockdev->blksize != INT13_BLKSIZE ) { - DBG ( "Invalid blocksize (%zd) for non-extended read/write\n", - blockdev->blksize ); + if ( int13->capacity.blksize != INT13_BLKSIZE ) { + DBGC ( int13, "\nINT 13 drive %02x invalid blocksize (%zd) " + "for non-extended read/write\n", + int13->drive, int13->capacity.blksize ); return -INT13_STATUS_INVALID; } /* Calculate parameters */ cylinder = ( ( ( ix86->regs.cl & 0xc0 ) << 2 ) | ix86->regs.ch ); - assert ( cylinder < drive->cylinders ); + assert ( cylinder < int13->cylinders ); head = ix86->regs.dh; - assert ( head < drive->heads ); + assert ( head < int13->heads ); sector = ( ix86->regs.cl & 0x3f ); - assert ( ( sector >= 1 ) && ( sector <= drive->sectors_per_track ) ); - lba = ( ( ( ( cylinder * drive->heads ) + head ) - * drive->sectors_per_track ) + sector - 1 ); + assert ( ( sector >= 1 ) && ( sector <= int13->sectors_per_track ) ); + 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 ); - DBG ( "C/H/S %d/%d/%d = LBA %#lx <-> %04x:%04x (count %d)\n", cylinder, - head, sector, lba, ix86->segs.es, ix86->regs.bx, count ); + 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 = io ( blockdev, lba, count, buffer ) ) != 0 ) { - DBG ( "INT 13 failed: %s\n", strerror ( rc ) ); + 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; } @@ -178,7 +559,7 @@ static int int13_rw_sectors ( struct int13_drive *drive, /** * INT 13, 02 - Read sectors * - * @v drive Emulated drive + * @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 @@ -188,16 +569,16 @@ static int int13_rw_sectors ( struct int13_drive *drive, * @ret status Status code * @ret al Number of sectors read */ -static int int13_read_sectors ( struct int13_drive *drive, +static int int13_read_sectors ( struct int13_drive *int13, struct i386_all_regs *ix86 ) { - DBG ( "Read: " ); - return int13_rw_sectors ( drive, ix86, drive->blockdev->op->read ); + DBGC2 ( int13, "Read: " ); + return int13_rw_sectors ( int13, ix86, block_read ); } /** * INT 13, 03 - Write sectors * - * @v drive Emulated drive + * @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 @@ -207,16 +588,16 @@ static int int13_read_sectors ( struct int13_drive *drive, * @ret status Status code * @ret al Number of sectors written */ -static int int13_write_sectors ( struct int13_drive *drive, +static int int13_write_sectors ( struct int13_drive *int13, struct i386_all_regs *ix86 ) { - DBG ( "Write: " ); - return int13_rw_sectors ( drive, ix86, drive->blockdev->op->write ); + DBGC2 ( int13, "Write: " ); + return int13_rw_sectors ( int13, ix86, block_write ); } /** * INT 13, 08 - Get drive parameters * - * @v drive Emulated drive + * @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 @@ -224,13 +605,13 @@ static int int13_write_sectors ( struct int13_drive *drive, * @ret dh Maximum head number * @ret dl Number of drives */ -static int int13_get_parameters ( struct int13_drive *drive, +static int int13_get_parameters ( struct int13_drive *int13, struct i386_all_regs *ix86 ) { - unsigned int max_cylinder = drive->cylinders - 1; - unsigned int max_head = drive->heads - 1; - unsigned int max_sector = drive->sectors_per_track; /* sic */ + unsigned int max_cylinder = int13->cylinders - 1; + unsigned int max_head = int13->heads - 1; + unsigned int max_sector = int13->sectors_per_track; /* sic */ - DBG ( "Get drive parameters\n" ); + DBGC2 ( int13, "Get drive parameters\n" ); ix86->regs.ch = ( max_cylinder & 0xff ); ix86->regs.cl = ( ( ( max_cylinder >> 8 ) << 6 ) | max_sector ); @@ -242,18 +623,18 @@ static int int13_get_parameters ( struct int13_drive *drive, /** * INT 13, 15 - Get disk type * - * @v drive Emulated drive + * @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 *drive, +static int int13_get_disk_type ( struct int13_drive *int13, struct i386_all_regs *ix86 ) { uint32_t blocks; - DBG ( "Get disk type\n" ); - blocks = ( ( drive->blockdev->blocks <= 0xffffffffUL ) ? - drive->blockdev->blocks : 0xffffffffUL ); + DBGC2 ( int13, "Get disk type\n" ); + blocks = ( ( int13->capacity.blocks <= 0xffffffffUL ) ? + int13->capacity.blocks : 0xffffffffUL ); ix86->regs.cx = ( blocks >> 16 ); ix86->regs.dx = ( blocks & 0xffff ); return INT13_DISK_TYPE_HDD; @@ -262,16 +643,16 @@ static int int13_get_disk_type ( struct int13_drive *drive, /** * INT 13, 41 - Extensions installation check * - * @v drive Emulated drive + * @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 *drive __unused, +static int int13_extension_check ( struct int13_drive *int13 __unused, struct i386_all_regs *ix86 ) { if ( ix86->regs.bx == 0x55aa ) { - DBG ( "INT 13 extensions installation check\n" ); + DBGC2 ( int13, "INT13 extensions installation check\n" ); ix86->regs.bx = 0xaa55; ix86->regs.cx = INT13_EXTENSION_LINEAR; return INT13_EXTENSION_VER_1_X; @@ -283,18 +664,19 @@ static int int13_extension_check ( struct int13_drive *drive __unused, /** * Extended read / write * - * @v drive Emulated drive + * @v int13 Emulated drive * @v ds:si Disk address packet - * @v io Read / write method + * @v block_rw Block read/write method * @ret status Status code */ -static int int13_extended_rw ( struct int13_drive *drive, +static int int13_extended_rw ( struct int13_drive *int13, struct i386_all_regs *ix86, - int ( * io ) ( struct block_device *blockdev, - uint64_t block, - unsigned long count, - userptr_t buffer ) ) { - struct block_device *blockdev = drive->blockdev; + 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; uint64_t lba; unsigned long count; @@ -307,12 +689,14 @@ static int int13_extended_rw ( struct int13_drive *drive, count = addr.count; buffer = real_to_user ( addr.buffer.segment, addr.buffer.offset ); - DBG ( "LBA %#llx <-> %04x:%04x (count %ld)\n", (unsigned long long)lba, - addr.buffer.segment, addr.buffer.offset, count ); + DBGC2 ( int13, "LBA %08llx <-> %04x:%04x (count %ld)\n", + ( ( unsigned long long ) lba ), addr.buffer.segment, + addr.buffer.offset, count ); /* Read from / write to block device */ - if ( ( rc = io ( blockdev, lba, count, buffer ) ) != 0 ) { - DBG ( "INT 13 failed: %s\n", strerror ( rc ) ); + 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 ) ); return -INT13_STATUS_READ_ERROR; } @@ -322,50 +706,50 @@ static int int13_extended_rw ( struct int13_drive *drive, /** * INT 13, 42 - Extended read * - * @v drive Emulated drive + * @v int13 Emulated drive * @v ds:si Disk address packet * @ret status Status code */ -static int int13_extended_read ( struct int13_drive *drive, +static int int13_extended_read ( struct int13_drive *int13, struct i386_all_regs *ix86 ) { - DBG ( "Extended read: " ); - return int13_extended_rw ( drive, ix86, drive->blockdev->op->read ); + DBGC2 ( int13, "Extended read: " ); + return int13_extended_rw ( int13, ix86, block_read ); } /** * INT 13, 43 - Extended write * - * @v drive Emulated drive + * @v int13 Emulated drive * @v ds:si Disk address packet * @ret status Status code */ -static int int13_extended_write ( struct int13_drive *drive, +static int int13_extended_write ( struct int13_drive *int13, struct i386_all_regs *ix86 ) { - DBG ( "Extended write: " ); - return int13_extended_rw ( drive, ix86, drive->blockdev->op->write ); + DBGC2 ( int13, "Extended write: " ); + return int13_extended_rw ( int13, ix86, block_write ); } /** * INT 13, 48 - Get extended parameters * - * @v drive Emulated drive + * @v int13 Emulated drive * @v ds:si Drive parameter table * @ret status Status code */ -static int int13_get_extended_parameters ( struct int13_drive *drive, +static int int13_get_extended_parameters ( struct int13_drive *int13, struct i386_all_regs *ix86 ) { struct int13_disk_parameters params = { .bufsize = sizeof ( params ), .flags = INT13_FL_DMA_TRANSPARENT, - .cylinders = drive->cylinders, - .heads = drive->heads, - .sectors_per_track = drive->sectors_per_track, - .sectors = drive->blockdev->blocks, - .sector_size = drive->blockdev->blksize, + .cylinders = int13->cylinders, + .heads = int13->heads, + .sectors_per_track = int13->sectors_per_track, + .sectors = int13->capacity.blocks, + .sector_size = int13->capacity.blksize, }; - DBG ( "Get extended drive parameters to %04x:%04x\n", - ix86->segs.ds, ix86->regs.si ); + DBGC2 ( int13, "Get extended drive parameters to %04x:%04x\n", + ix86->segs.ds, ix86->regs.si ); copy_to_real ( ix86->segs.ds, ix86->regs.si, ¶ms, sizeof ( params ) ); @@ -379,72 +763,74 @@ static int int13_get_extended_parameters ( struct int13_drive *drive, static __asmcall void int13 ( struct i386_all_regs *ix86 ) { int command = ix86->regs.ah; unsigned int bios_drive = ix86->regs.dl; - struct int13_drive *drive; + struct int13_drive *int13; int status; /* Check BIOS hasn't killed off our drive */ int13_check_num_drives(); - list_for_each_entry ( drive, &drives, list ) { + list_for_each_entry ( int13, &int13s, list ) { - if ( bios_drive != drive->drive ) { + if ( bios_drive != int13->drive ) { /* Remap any accesses to this drive's natural number */ - if ( bios_drive == drive->natural_drive ) { - DBG ( "INT 13,%04x (%02x) remapped to " - "(%02x)\n", ix86->regs.ax, - bios_drive, drive->drive ); - ix86->regs.dl = drive->drive; + 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; } continue; } - DBG ( "INT 13,%04x (%02x): ", ix86->regs.ax, drive->drive ); + DBGC2 ( int13, "INT13,%02x (%02x): ", + ix86->regs.ah, int13->drive ); switch ( command ) { case INT13_RESET: - status = int13_reset ( drive, ix86 ); + status = int13_reset ( int13, ix86 ); break; case INT13_GET_LAST_STATUS: - status = int13_get_last_status ( drive, ix86 ); + status = int13_get_last_status ( int13, ix86 ); break; case INT13_READ_SECTORS: - status = int13_read_sectors ( drive, ix86 ); + status = int13_read_sectors ( int13, ix86 ); break; case INT13_WRITE_SECTORS: - status = int13_write_sectors ( drive, ix86 ); + status = int13_write_sectors ( int13, ix86 ); break; case INT13_GET_PARAMETERS: - status = int13_get_parameters ( drive, ix86 ); + status = int13_get_parameters ( int13, ix86 ); break; case INT13_GET_DISK_TYPE: - status = int13_get_disk_type ( drive, ix86 ); + status = int13_get_disk_type ( int13, ix86 ); break; case INT13_EXTENSION_CHECK: - status = int13_extension_check ( drive, ix86 ); + status = int13_extension_check ( int13, ix86 ); break; case INT13_EXTENDED_READ: - status = int13_extended_read ( drive, ix86 ); + status = int13_extended_read ( int13, ix86 ); break; case INT13_EXTENDED_WRITE: - status = int13_extended_write ( drive, ix86 ); + status = int13_extended_write ( int13, ix86 ); break; case INT13_GET_EXTENDED_PARAMETERS: - status = int13_get_extended_parameters ( drive, ix86 ); + status = int13_get_extended_parameters ( int13, ix86 ); break; default: - DBG ( "*** Unrecognised INT 13 ***\n" ); + DBGC2 ( int13, "*** Unrecognised INT13 ***\n" ); status = -INT13_STATUS_INVALID; break; } /* Store status for INT 13,01 */ - drive->last_status = status; + int13->last_status = status; /* Negative status indicates an error */ if ( status < 0 ) { status = -status; - DBG ( "INT 13 returning failure status %x\n", status ); + DBGC ( int13, "INT13,%02x (%02x) failed with status " + "%02x\n", ix86->regs.ah, int13->drive, status ); } else { ix86->flags &= ~CF; } @@ -461,7 +847,7 @@ static __asmcall void int13 ( struct i386_all_regs *ix86 ) { * Hook INT 13 handler * */ -static void hook_int13 ( void ) { +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()). @@ -517,136 +903,188 @@ static void hook_int13 ( void ) { /** * Unhook INT 13 handler */ -static void unhook_int13 ( void ) { +static void int13_unhook_vector ( void ) { unhook_bios_interrupt ( 0x13, ( unsigned int ) int13_wrapper, &int13_vector ); } /** - * Guess INT 13 drive geometry + * Handle INT 13 emulated drive underlying block device closing * - * @v drive Emulated drive - * - * Guesses the drive geometry by inspecting the partition table. + * @v int13 Emulated drive + * @v rc Reason for close */ -static void guess_int13_geometry ( struct int13_drive *drive ) { - struct master_boot_record mbr; - struct partition_table_entry *partition; - unsigned int guessed_heads = 255; - unsigned int guessed_sectors_per_track = 63; - unsigned long blocks; - unsigned long blocks_per_cyl; - unsigned int i; +static void int13_block_close ( struct int13_drive *int13, int rc ) { - /* Don't even try when the blksize is invalid for C/H/S access */ - if ( drive->blockdev->blksize != INT13_BLKSIZE ) - return; + /* Any closing is an error from our point of view */ + if ( rc == 0 ) + rc = -ENOTCONN; - /* Scan through partition table and modify guesses for heads - * and sectors_per_track if we find any used partitions. + 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 ); + + /* Further INT 13 calls will fail immediately. The caller may + * use INT 13,00 to reset the drive. */ - if ( drive->blockdev->op->read ( drive->blockdev, 0, 1, - virt_to_user ( &mbr ) ) == 0 ) { - for ( i = 0 ; i < 4 ; i++ ) { - partition = &mbr.partitions[i]; - if ( ! partition->type ) - continue; - guessed_heads = - ( PART_HEAD ( partition->chs_end ) + 1 ); - guessed_sectors_per_track = - PART_SECTOR ( partition->chs_end ); - DBG ( "Guessing C/H/S xx/%d/%d based on partition " - "%d\n", guessed_heads, - guessed_sectors_per_track, ( i + 1 ) ); - } - } else { - DBG ( "Could not read partition table to guess geometry\n" ); - } +} - /* Apply guesses if no geometry already specified */ - if ( ! drive->heads ) - drive->heads = guessed_heads; - if ( ! drive->sectors_per_track ) - drive->sectors_per_track = guessed_sectors_per_track; - if ( ! drive->cylinders ) { - /* Avoid attempting a 64-bit divide on a 32-bit system */ - blocks = ( ( drive->blockdev->blocks <= ULONG_MAX ) ? - drive->blockdev->blocks : ULONG_MAX ); - blocks_per_cyl = ( drive->heads * drive->sectors_per_track ); - assert ( blocks_per_cyl != 0 ); - drive->cylinders = ( blocks / blocks_per_cyl ); - if ( drive->cylinders > 1024 ) - drive->cylinders = 1024; - } +/** INT 13 drive interface operations */ +static struct interface_operation int13_block_op[] = { + 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 ); } /** - * Register INT 13 emulated drive + * Hook INT 13 emulated drive * - * @v drive Emulated drive + * @v uri URI + * @v drive Requested drive number + * @ret drive Assigned 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). - * - * The underlying block device must be valid. A drive number and - * geometry will be assigned if left blank. */ -void register_int13_drive ( struct int13_drive *drive ) { +static int int13_hook ( struct uri *uri, unsigned int drive ) { + struct int13_drive *int13; uint8_t num_drives; + unsigned int natural_drive; + int rc; - /* Give drive a default geometry if none specified */ - guess_int13_geometry ( drive ); - - /* Assign natural drive number */ + /* Calculate drive number */ get_real ( num_drives, BDA_SEG, BDA_NUM_DRIVES ); - drive->natural_drive = ( num_drives | 0x80 ); + natural_drive = ( num_drives | 0x80 ); + if ( drive == INT13_USE_NATURAL_DRIVE ) + drive = natural_drive; + drive |= 0x80; + + /* 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; + } + } - /* Assign drive number */ - if ( ( drive->drive & 0xff ) == 0xff ) { - /* Drive number == -1 => use natural drive number */ - drive->drive = drive->natural_drive; - } else { - /* Use specified drive number (+0x80 if necessary) */ - drive->drive |= 0x80; + /* 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; - DBG ( "Registered INT13 drive %02x (naturally %02x) with C/H/S " - "geometry %d/%d/%d\n", drive->drive, drive->natural_drive, - drive->cylinders, drive->heads, drive->sectors_per_track ); + /* Give drive a default geometry */ + if ( ( rc = int13_guess_geometry ( int13 ) ) != 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 ( &drives ) ) - hook_int13(); + if ( list_empty ( &int13s ) ) + int13_hook_vector(); /* Add to list of emulated drives */ - list_add ( &drive->list, &drives ); + list_add ( &int13->list, &int13s ); /* Update BIOS drive count */ int13_set_num_drives(); + + return int13->drive; + + err_guess_geometry: + err_reopen_block: + intf_shutdown ( &int13->block, rc ); + ref_put ( &int13->refcnt ); + err_zalloc: + err_in_use: + return rc; } /** - * Unregister INT 13 emulated drive + * Find INT 13 emulated drive by drive number * - * @v drive Emulated drive + * @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). */ -void unregister_int13_drive ( struct int13_drive *drive ) { +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 ( &drive->list ); + list_del ( &int13->list ); - /* Should adjust BIOS drive count, but it's difficult to do so - * reliably. + /* Should adjust BIOS drive count, but it's difficult + * to do so reliably. */ - DBG ( "Unregistered INT13 drive %02x\n", drive->drive ); + DBGC ( int13, "INT13 drive %02x unregsitered\n", int13->drive ); /* Unhook INT 13 vector if no more drives */ - if ( list_empty ( &drives ) ) - unhook_int13(); + if ( list_empty ( &int13s ) ) + int13_unhook_vector(); + + /* Drop list's reference to drive */ + ref_put ( &int13->refcnt ); } /** @@ -662,13 +1100,13 @@ void unregister_int13_drive ( struct int13_drive *drive ) { * * Note that this function can never return success, by definition. */ -int int13_boot ( unsigned int drive ) { +static int int13_boot ( unsigned int drive ) { struct memory_map memmap; int status, signature; int discard_c, discard_d; int rc; - DBG ( "Booting from INT 13 drive %02x\n", drive ); + DBG ( "INT13 drive %02x booting\n", drive ); /* Use INT 13 to read the boot sector */ __asm__ __volatile__ ( REAL_CODE ( "pushw %%es\n\t" @@ -692,8 +1130,8 @@ int int13_boot ( unsigned int drive ) { /* Check signature is correct */ if ( signature != be16_to_cpu ( 0x55aa ) ) { - DBG ( "Invalid disk signature %#04x (should be 0x55aa)\n", - cpu_to_be16 ( signature ) ); + DBG ( "INT13 drive %02x invalid disk signature %#04x (should " + "be 0x55aa)\n", drive, cpu_to_be16 ( signature ) ); return -ENOEXEC; } @@ -706,10 +1144,74 @@ int int13_boot ( unsigned int drive ) { /* Jump to boot sector */ if ( ( rc = call_bootsector ( 0x0, 0x7c00, drive ) ) != 0 ) { - DBG ( "INT 13 drive %02x boot returned: %s\n", + 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; + } + + /* 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 ( 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 ); |