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int13.c
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/*
* 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/blockdev.h>
#include <ipxe/io.h>
#include <ipxe/acpi.h>
#include <ipxe/sanboot.h>
#include <ipxe/device.h>
#include <ipxe/pci.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.
*
*/
/** INT 13 SAN device private data */
struct int13_data {
/** BIOS natural drive number (0x00-0xff)
*
* This is the drive number that would have been assigned by
* 'naturally' appending the drive to the end of the BIOS
* drive list.
*
* If the emulated drive replaces a preexisting drive, this is
* the drive number that the preexisting drive gets remapped
* to.
*/
unsigned int natural_drive;
/** Number of cylinders
*
* The cylinder number field in an INT 13 call is ten bits
* wide, giving a maximum of 1024 cylinders. Conventionally,
* when the 7.8GB limit of a CHS address is exceeded, it is
* the number of cylinders that is increased beyond the
* addressable limit.
*/
unsigned int cylinders;
/** Number of heads
*
* The head number field in an INT 13 call is eight bits wide,
* giving a maximum of 256 heads. However, apparently all
* versions of MS-DOS up to and including Win95 fail with 256
* heads, so the maximum encountered in practice is 255.
*/
unsigned int heads;
/** Number of sectors per track
*
* The sector number field in an INT 13 call is six bits wide,
* giving a maximum of 63 sectors, since sector numbering
* (unlike head and cylinder numbering) starts at 1, not 0.
*/
unsigned int sectors_per_track;
/** Address of El Torito boot catalog (if any) */
unsigned int boot_catalog;
/** Status of last operation */
int last_status;
};
/** Vector for chaining to other INT 13 handlers */
static struct segoff __text16 ( int13_vector );
#define int13_vector __use_text16 ( int13_vector )
/** Assembly wrapper */
extern void int13_wrapper ( void );
/** Dummy floppy disk parameter table */
static struct int13_fdd_parameters __data16 ( int13_fdd_params ) = {
/* 512 bytes per sector */
.bytes_per_sector = 0x02,
/* Highest sectors per track that we ever return */
.sectors_per_track = 48,
};
#define int13_fdd_params __use_data16 ( int13_fdd_params )
/**
* Equipment word
*
* This is a cached copy of the BIOS Data Area equipment word at
* 40:10.
*/
static uint16_t equipment_word;
/**
* Number of BIOS floppy disk drives
*
* This is derived from the equipment word. It is held in .text16 to
* allow for easy access by the INT 13,08 wrapper.
*/
static uint8_t __text16 ( num_fdds );
#define num_fdds __use_text16 ( num_fdds )
/**
* Number of BIOS hard disk drives
*
* This is a cached copy of the BIOS Data Area number of hard disk
* drives at 40:75. It is held in .text16 to allow for easy access by
* the INT 13,08 wrapper.
*/
static uint8_t __text16 ( num_drives );
#define num_drives __use_text16 ( num_drives )
/**
* Calculate SAN device capacity (limited to 32 bits)
*
* @v sandev SAN device
* @ret blocks Number of blocks
*/
static inline uint32_t int13_capacity32 ( struct san_device *sandev ) {
uint64_t capacity = sandev_capacity ( sandev );
return ( ( capacity <= 0xffffffffUL ) ? capacity : 0xffffffff );
}
/**
* Test if SAN device is a floppy disk drive
*
* @v sandev SAN device
* @ret is_fdd SAN device is a floppy disk drive
*/
static inline int int13_is_fdd ( struct san_device *sandev ) {
return ( ! ( sandev->drive & 0x80 ) );
}
/**
* Parse El Torito parameters
*
* @v sandev SAN device
* @v scratch Scratch area for single-sector reads
* @ret rc Return status code
*
* Reads and parses El Torito parameters, if present.
*/
static int int13_parse_eltorito ( struct san_device *sandev, void *scratch ) {
struct int13_data *int13 = sandev->priv;
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;
int rc;
/* Read boot record volume descriptor */
if ( ( rc = sandev_read ( sandev, ELTORITO_LBA, 1, boot ) ) != 0 ) {
DBGC ( sandev->drive, "INT13 drive %02x could not read El "
"Torito boot record volume descriptor: %s\n",
sandev->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 ( sandev->drive, "INT13 drive %02x has an El Torito boot "
"catalog at LBA %08x\n", sandev->drive,
int13->boot_catalog );
} else {
DBGC ( sandev->drive, "INT13 drive %02x has no El Torito boot "
"catalog\n", sandev->drive );
}
return 0;
}
/**
* Guess INT 13 hard disk drive geometry
*
* @v sandev SAN device
* @v scratch Scratch area for single-sector reads
* @ret heads Guessed number of heads
* @ret sectors Guessed number of sectors per track
* @ret rc Return status code
*
* Guesses the drive geometry by inspecting the partition table.
*/
static int int13_guess_geometry_hdd ( struct san_device *sandev, void *scratch,
unsigned int *heads,
unsigned int *sectors ) {
struct master_boot_record *mbr = scratch;
struct partition_table_entry *partition;
unsigned int i;
unsigned int start_cylinder;
unsigned int start_head;
unsigned int start_sector;
unsigned int end_head;
unsigned int end_sector;
int rc;
/* Read partition table */
if ( ( rc = sandev_read ( sandev, 0, 1, mbr ) ) != 0 ) {
DBGC ( sandev->drive, "INT13 drive %02x could not read "
"partition table to guess geometry: %s\n",
sandev->drive, strerror ( rc ) );
return rc;
}
DBGC2 ( sandev->drive, "INT13 drive %02x has MBR:\n", sandev->drive );
DBGC2_HDA ( sandev->drive, 0, mbr, sizeof ( *mbr ) );
DBGC ( sandev->drive, "INT13 drive %02x has signature %08x\n",
sandev->drive, mbr->signature );
/* Scan through partition table and modify guesses for
* heads and sectors_per_track if we find any used
* partitions.
*/
*heads = 0;
*sectors = 0;
for ( i = 0 ; i < 4 ; i++ ) {
/* Skip empty partitions */
partition = &mbr->partitions[i];
if ( ! partition->type )
continue;
/* If partition starts on cylinder 0 then we can
* unambiguously determine the number of sectors.
*/
start_cylinder = PART_CYLINDER ( partition->chs_start );
start_head = PART_HEAD ( partition->chs_start );
start_sector = PART_SECTOR ( partition->chs_start );
if ( ( start_cylinder == 0 ) && ( start_head != 0 ) ) {
*sectors = ( ( partition->start + 1 - start_sector ) /
start_head );
DBGC ( sandev->drive, "INT13 drive %02x guessing "
"C/H/S xx/xx/%d based on partition %d\n",
sandev->drive, *sectors, ( i + 1 ) );
}
/* If partition ends on a higher head or sector number
* than our current guess, then increase the guess.
*/
end_head = PART_HEAD ( partition->chs_end );
end_sector = PART_SECTOR ( partition->chs_end );
if ( ( end_head + 1 ) > *heads ) {
*heads = ( end_head + 1 );
DBGC ( sandev->drive, "INT13 drive %02x guessing "
"C/H/S xx/%d/xx based on partition %d\n",
sandev->drive, *heads, ( i + 1 ) );
}
if ( end_sector > *sectors ) {
*sectors = end_sector;
DBGC ( sandev->drive, "INT13 drive %02x guessing "
"C/H/S xx/xx/%d based on partition %d\n",
sandev->drive, *sectors, ( i + 1 ) );
}
}
/* Default guess is xx/255/63 */
if ( ! *heads )
*heads = 255;
if ( ! *sectors )
*sectors = 63;
return 0;
}
/** Recognised floppy disk geometries */
static const struct int13_fdd_geometry int13_fdd_geometries[] = {
INT13_FDD_GEOMETRY ( 40, 1, 8 ),
INT13_FDD_GEOMETRY ( 40, 1, 9 ),
INT13_FDD_GEOMETRY ( 40, 2, 8 ),
INT13_FDD_GEOMETRY ( 40, 1, 9 ),
INT13_FDD_GEOMETRY ( 80, 2, 8 ),
INT13_FDD_GEOMETRY ( 80, 2, 9 ),
INT13_FDD_GEOMETRY ( 80, 2, 15 ),
INT13_FDD_GEOMETRY ( 80, 2, 18 ),
INT13_FDD_GEOMETRY ( 80, 2, 20 ),
INT13_FDD_GEOMETRY ( 80, 2, 21 ),
INT13_FDD_GEOMETRY ( 82, 2, 21 ),
INT13_FDD_GEOMETRY ( 83, 2, 21 ),
INT13_FDD_GEOMETRY ( 80, 2, 22 ),
INT13_FDD_GEOMETRY ( 80, 2, 23 ),
INT13_FDD_GEOMETRY ( 80, 2, 24 ),
INT13_FDD_GEOMETRY ( 80, 2, 36 ),
INT13_FDD_GEOMETRY ( 80, 2, 39 ),
INT13_FDD_GEOMETRY ( 80, 2, 40 ),
INT13_FDD_GEOMETRY ( 80, 2, 44 ),
INT13_FDD_GEOMETRY ( 80, 2, 48 ),
};
/**
* Guess INT 13 floppy disk drive geometry
*
* @v sandev SAN device
* @ret heads Guessed number of heads
* @ret sectors Guessed number of sectors per track
* @ret rc Return status code
*
* Guesses the drive geometry by inspecting the disk size.
*/
static int int13_guess_geometry_fdd ( struct san_device *sandev,
unsigned int *heads,
unsigned int *sectors ) {
unsigned int blocks = sandev_capacity ( sandev );
const struct int13_fdd_geometry *geometry;
unsigned int cylinders;
unsigned int i;
/* Look for a match against a known geometry */
for ( i = 0 ; i < ( sizeof ( int13_fdd_geometries ) /
sizeof ( int13_fdd_geometries[0] ) ) ; i++ ) {
geometry = &int13_fdd_geometries[i];
cylinders = INT13_FDD_CYLINDERS ( geometry );
*heads = INT13_FDD_HEADS ( geometry );
*sectors = INT13_FDD_SECTORS ( geometry );
if ( ( cylinders * (*heads) * (*sectors) ) == blocks ) {
DBGC ( sandev->drive, "INT13 drive %02x guessing "
"C/H/S %d/%d/%d based on size %dK\n",
sandev->drive, cylinders, *heads, *sectors,
( blocks / 2 ) );
return 0;
}
}
/* Otherwise, assume a partial disk image in the most common
* format (1440K, 80/2/18).
*/
*heads = 2;
*sectors = 18;
DBGC ( sandev->drive, "INT13 drive %02x guessing C/H/S xx/%d/%d "
"based on size %dK\n", sandev->drive, *heads, *sectors,
( blocks / 2 ) );
return 0;
}
/**
* Guess INT 13 drive geometry
*
* @v sandev SAN device
* @v scratch Scratch area for single-sector reads
* @ret rc Return status code
*/
static int int13_guess_geometry ( struct san_device *sandev, void *scratch ) {
struct int13_data *int13 = sandev->priv;
unsigned int guessed_heads;
unsigned int guessed_sectors;
unsigned int blocks;
unsigned int blocks_per_cyl;
int rc;
/* Guess geometry according to drive type */
if ( int13_is_fdd ( sandev ) ) {
if ( ( rc = int13_guess_geometry_fdd ( sandev, &guessed_heads,
&guessed_sectors )) != 0)
return rc;
} else {
if ( ( rc = int13_guess_geometry_hdd ( sandev, scratch,
&guessed_heads,
&guessed_sectors )) != 0)
return rc;
}
/* Apply guesses if no geometry already specified */
if ( ! int13->heads )
int13->heads = guessed_heads;
if ( ! int13->sectors_per_track )
int13->sectors_per_track = guessed_sectors;
if ( ! int13->cylinders ) {
/* Avoid attempting a 64-bit divide on a 32-bit system */
blocks = int13_capacity32 ( sandev );
blocks_per_cyl = ( int13->heads * int13->sectors_per_track );
assert ( blocks_per_cyl != 0 );
int13->cylinders = ( blocks / blocks_per_cyl );
if ( int13->cylinders > 1024 )
int13->cylinders = 1024;
}
return 0;
}
/**
* Update BIOS drive count
*/
static void int13_sync_num_drives ( void ) {
struct san_device *sandev;
struct int13_data *int13;
uint8_t *counter;
uint8_t max_drive;
uint8_t required;
/* Get current drive counts */
get_real ( equipment_word, BDA_SEG, BDA_EQUIPMENT_WORD );
get_real ( num_drives, BDA_SEG, BDA_NUM_DRIVES );
num_fdds = ( ( equipment_word & 0x0001 ) ?
( ( ( equipment_word >> 6 ) & 0x3 ) + 1 ) : 0 );
/* Ensure count is large enough to cover all of our SAN devices */
for_each_sandev ( sandev ) {
int13 = sandev->priv;
counter = ( int13_is_fdd ( sandev ) ? &num_fdds : &num_drives );
max_drive = sandev->drive;
if ( max_drive < int13->natural_drive )
max_drive = int13->natural_drive;
required = ( ( max_drive & 0x7f ) + 1 );
if ( *counter < required ) {
*counter = required;
DBGC ( sandev->drive, "INT13 drive %02x added to "
"drive count: %d HDDs, %d FDDs\n",
sandev->drive, num_drives, num_fdds );
}
}
/* Update current drive count */
equipment_word &= ~( ( 0x3 << 6 ) | 0x0001 );
if ( num_fdds ) {
equipment_word |= ( 0x0001 |
( ( ( num_fdds - 1 ) & 0x3 ) << 6 ) );
}
put_real ( equipment_word, BDA_SEG, BDA_EQUIPMENT_WORD );
put_real ( num_drives, BDA_SEG, BDA_NUM_DRIVES );
}
/**
* Check number of drives
*/
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 sandev SAN device
* @ret status Status code
*/
static int int13_reset ( struct san_device *sandev,
struct i386_all_regs *ix86 __unused ) {
int rc;
DBGC2 ( sandev->drive, "Reset drive\n" );
/* Reset SAN device */
if ( ( rc = sandev_reset ( sandev ) ) != 0 )
return -INT13_STATUS_RESET_FAILED;
return 0;
}
/**
* INT 13, 01 - Get status of last operation
*
* @v sandev SAN device
* @ret status Status code
*/
static int int13_get_last_status ( struct san_device *sandev,
struct i386_all_regs *ix86 __unused ) {
struct int13_data *int13 = sandev->priv;
DBGC2 ( sandev->drive, "Get status of last operation\n" );
return int13->last_status;
}
/**
* Read / write sectors
*
* @v sandev SAN device
* @v al Number of sectors to read or write (must be nonzero)
* @v ch Low bits of cylinder number
* @v cl (bits 7:6) High bits of cylinder number
* @v cl (bits 5:0) Sector number
* @v dh Head number
* @v es:bx Data buffer
* @v sandev_rw SAN device read/write method
* @ret status Status code
* @ret al Number of sectors read or written
*/
static int int13_rw_sectors ( struct san_device *sandev,
struct i386_all_regs *ix86,
int ( * sandev_rw ) ( struct san_device *sandev,
uint64_t lba,
unsigned int count,
void *buffer ) ) {
struct int13_data *int13 = sandev->priv;
unsigned int cylinder, head, sector;
unsigned long lba;
unsigned int count;
void *buffer;
int rc;
/* Validate blocksize */
if ( sandev_blksize ( sandev ) != INT13_BLKSIZE ) {
DBGC ( sandev->drive, "\nINT 13 drive %02x invalid blocksize "
"(%zd) for non-extended read/write\n",
sandev->drive, sandev_blksize ( sandev ) );
return -INT13_STATUS_INVALID;
}
/* Calculate parameters */
cylinder = ( ( ( ix86->regs.cl & 0xc0 ) << 2 ) | ix86->regs.ch );
head = ix86->regs.dh;
sector = ( ix86->regs.cl & 0x3f );
if ( ( cylinder >= int13->cylinders ) ||
( head >= int13->heads ) ||
( sector < 1 ) || ( sector > int13->sectors_per_track ) ) {
DBGC ( sandev->drive, "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_virt ( ix86->segs.es, ix86->regs.bx );
DBGC2 ( sandev->drive, "C/H/S %d/%d/%d = LBA %08lx <-> %04x:%04x "
"(count %d)\n", cylinder, head, sector, lba, ix86->segs.es,
ix86->regs.bx, count );
/* Read from / write to block device */
if ( ( rc = sandev_rw ( sandev, lba, count, buffer ) ) != 0 ){
DBGC ( sandev->drive, "INT13 drive %02x I/O failed: %s\n",
sandev->drive, strerror ( rc ) );
return -INT13_STATUS_READ_ERROR;
}
return 0;
}
/**
* INT 13, 02 - Read sectors
*
* @v sandev SAN device
* @v al Number of sectors to read (must be nonzero)
* @v ch Low bits of cylinder number
* @v cl (bits 7:6) High bits of cylinder number
* @v cl (bits 5:0) Sector number
* @v dh Head number
* @v es:bx Data buffer
* @ret status Status code
* @ret al Number of sectors read
*/
static int int13_read_sectors ( struct san_device *sandev,
struct i386_all_regs *ix86 ) {
DBGC2 ( sandev->drive, "Read: " );
return int13_rw_sectors ( sandev, ix86, sandev_read );
}
/**
* INT 13, 03 - Write sectors
*
* @v sandev SAN device
* @v al Number of sectors to write (must be nonzero)
* @v ch Low bits of cylinder number
* @v cl (bits 7:6) High bits of cylinder number
* @v cl (bits 5:0) Sector number
* @v dh Head number
* @v es:bx Data buffer
* @ret status Status code
* @ret al Number of sectors written
*/
static int int13_write_sectors ( struct san_device *sandev,
struct i386_all_regs *ix86 ) {
DBGC2 ( sandev->drive, "Write: " );
return int13_rw_sectors ( sandev, ix86, sandev_write );
}
/**
* INT 13, 08 - Get drive parameters
*
* @v sandev SAN device
* @ret status Status code
* @ret ch Low bits of maximum cylinder number
* @ret cl (bits 7:6) High bits of maximum cylinder number
* @ret cl (bits 5:0) Maximum sector number
* @ret dh Maximum head number
* @ret dl Number of drives
*/
static int int13_get_parameters ( struct san_device *sandev,
struct i386_all_regs *ix86 ) {
struct int13_data *int13 = sandev->priv;
unsigned int max_cylinder = int13->cylinders - 1;
unsigned int max_head = int13->heads - 1;
unsigned int max_sector = int13->sectors_per_track; /* sic */
DBGC2 ( sandev->drive, "Get drive parameters\n" );
/* Validate blocksize */
if ( sandev_blksize ( sandev ) != INT13_BLKSIZE ) {
DBGC ( sandev->drive, "\nINT 13 drive %02x invalid blocksize "
"(%zd) for non-extended parameters\n",
sandev->drive, sandev_blksize ( sandev ) );
return -INT13_STATUS_INVALID;
}
/* Common parameters */
ix86->regs.ch = ( max_cylinder & 0xff );
ix86->regs.cl = ( ( ( max_cylinder >> 8 ) << 6 ) | max_sector );
ix86->regs.dh = max_head;
ix86->regs.dl = ( int13_is_fdd ( sandev ) ? num_fdds : num_drives );
/* Floppy-specific parameters */
if ( int13_is_fdd ( sandev ) ) {
ix86->regs.bl = INT13_FDD_TYPE_1M44;
ix86->segs.es = rm_ds;
ix86->regs.di = __from_data16 ( &int13_fdd_params );
}
return 0;
}
/**
* INT 13, 15 - Get disk type
*
* @v sandev SAN device
* @ret ah Type code
* @ret cx:dx Sector count
* @ret status Status code / disk type
*/
static int int13_get_disk_type ( struct san_device *sandev,
struct i386_all_regs *ix86 ) {
uint32_t blocks;
DBGC2 ( sandev->drive, "Get disk type\n" );
if ( int13_is_fdd ( sandev ) ) {
return INT13_DISK_TYPE_FDD;
} else {
blocks = int13_capacity32 ( sandev );
ix86->regs.cx = ( blocks >> 16 );
ix86->regs.dx = ( blocks & 0xffff );
return INT13_DISK_TYPE_HDD;
}
}
/**
* INT 13, 41 - Extensions installation check
*
* @v sandev SAN device
* @v bx 0x55aa
* @ret bx 0xaa55
* @ret cx Extensions API support bitmap
* @ret status Status code / API version
*/
static int int13_extension_check ( struct san_device *sandev,
struct i386_all_regs *ix86 ) {
if ( ( ix86->regs.bx == 0x55aa ) && ! int13_is_fdd ( sandev ) ) {
DBGC2 ( sandev->drive, "INT13 extensions check\n" );
ix86->regs.bx = 0xaa55;
ix86->regs.cx = ( INT13_EXTENSION_LINEAR |
INT13_EXTENSION_EDD |
INT13_EXTENSION_64BIT );
return INT13_EXTENSION_VER_3_0;
} else {
return -INT13_STATUS_INVALID;
}
}
/**
* Extended read / write
*
* @v sandev SAN device
* @v ds:si Disk address packet
* @v sandev_rw SAN device read/write method
* @ret status Status code
*/
static int int13_extended_rw ( struct san_device *sandev,
struct i386_all_regs *ix86,
int ( * sandev_rw ) ( struct san_device *sandev,
uint64_t lba,
unsigned int count,
void *buffer ) ) {
struct int13_disk_address addr;
uint8_t bufsize;
uint64_t lba;
unsigned long count;
void *buffer;
int rc;
/* Extended reads are not allowed on floppy drives.
* ELTORITO.SYS seems to assume that we are really a CD-ROM if
* we support extended reads for a floppy drive.
*/
if ( int13_is_fdd ( sandev ) )
return -INT13_STATUS_INVALID;
/* Get buffer size */
get_real ( bufsize, ix86->segs.ds,
( ix86->regs.si + offsetof ( typeof ( addr ), bufsize ) ) );
if ( bufsize < offsetof ( typeof ( addr ), buffer_phys ) ) {
DBGC2 ( sandev->drive, "<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 ( sandev->drive, "LBA %08llx <-> ",
( ( unsigned long long ) lba ) );
if ( ( addr.count == 0xff ) ||
( ( addr.buffer.segment == 0xffff ) &&
( addr.buffer.offset == 0xffff ) ) ) {
buffer = phys_to_virt ( addr.buffer_phys );
DBGC2 ( sandev->drive, "%08llx",
( ( unsigned long long ) addr.buffer_phys ) );
} else {
buffer = real_to_virt ( addr.buffer.segment,
addr.buffer.offset );
DBGC2 ( sandev->drive, "%04x:%04x", addr.buffer.segment,
addr.buffer.offset );
}
if ( addr.count <= 0x7f ) {
count = addr.count;
} else if ( addr.count == 0xff ) {
count = addr.long_count;
} else {
DBGC2 ( sandev->drive, " <invalid count %#02x>\n", addr.count );
return -INT13_STATUS_INVALID;
}
DBGC2 ( sandev->drive, " (count %ld)\n", count );
/* Read from / write to block device */
if ( ( rc = sandev_rw ( sandev, lba, count, buffer ) ) != 0 ) {
DBGC ( sandev->drive, "INT13 drive %02x extended I/O failed: "
"%s\n", sandev->drive, strerror ( rc ) );
/* Record that no blocks were transferred successfully */
addr.count = 0;
put_real ( addr.count, ix86->segs.ds,
( ix86->regs.si +
offsetof ( typeof ( addr ), count ) ) );
return -INT13_STATUS_READ_ERROR;
}
return 0;
}
/**
* INT 13, 42 - Extended read
*
* @v sandev SAN device
* @v ds:si Disk address packet
* @ret status Status code
*/
static int int13_extended_read ( struct san_device *sandev,
struct i386_all_regs *ix86 ) {
DBGC2 ( sandev->drive, "Extended read: " );
return int13_extended_rw ( sandev, ix86, sandev_read );
}
/**
* INT 13, 43 - Extended write
*
* @v sandev SAN device
* @v ds:si Disk address packet
* @ret status Status code
*/
static int int13_extended_write ( struct san_device *sandev,
struct i386_all_regs *ix86 ) {
DBGC2 ( sandev->drive, "Extended write: " );
return int13_extended_rw ( sandev, ix86, sandev_write );
}
/**
* INT 13, 44 - Verify sectors
*
* @v sandev SAN device
* @v ds:si Disk address packet
* @ret status Status code
*/
static int int13_extended_verify ( struct san_device *sandev,
struct i386_all_regs *ix86 ) {
struct int13_disk_address addr;
uint64_t lba;
unsigned long count;
/* Read parameters from disk address structure */
if ( DBG_EXTRA ) {
copy_from_real ( &addr, ix86->segs.ds, ix86->regs.si,
sizeof ( addr ));
lba = addr.lba;
count = addr.count;
DBGC2 ( sandev->drive, "Verify: LBA %08llx (count %ld)\n",
( ( unsigned long long ) lba ), count );
}
/* We have no mechanism for verifying sectors */
return -INT13_STATUS_INVALID;
}
/**
* INT 13, 44 - Extended seek
*
* @v sandev SAN device
* @v ds:si Disk address packet
* @ret status Status code
*/
static int int13_extended_seek ( struct san_device *sandev,
struct i386_all_regs *ix86 ) {
struct int13_disk_address addr;
uint64_t lba;
unsigned long count;
/* Read parameters from disk address structure */
if ( DBG_EXTRA ) {
copy_from_real ( &addr, ix86->segs.ds, ix86->regs.si,
sizeof ( addr ));
lba = addr.lba;
count = addr.count;
DBGC2 ( sandev->drive, "Seek: LBA %08llx (count %ld)\n",
( ( unsigned long long ) lba ), count );
}
/* Ignore and return success */
return 0;
}
/**
* Build device path information
*
* @v sandev SAN device
* @v dpi Device path information
* @ret rc Return status code
*/
static int int13_device_path_info ( struct san_device *sandev,
struct edd_device_path_information *dpi ) {
struct san_path *sanpath;
struct device *device;
struct device_description *desc;
unsigned int i;
uint8_t sum = 0;
int rc;
/* Reopen block device if necessary */
if ( sandev_needs_reopen ( sandev ) &&
( ( rc = sandev_reopen ( sandev ) ) != 0 ) )
return rc;
sanpath = sandev->active;
assert ( sanpath != NULL );
/* Get underlying hardware device */
device = identify_device ( &sanpath->block );
if ( ! device ) {
DBGC ( sandev->drive, "INT13 drive %02x cannot identify "
"hardware device\n", sandev->drive );
return -ENODEV;
}
/* Fill in bus type and interface path */
desc = &device->desc;
switch ( desc->bus_type ) {
case BUS_TYPE_PCI:
dpi->host_bus_type.type = EDD_BUS_TYPE_PCI;
dpi->interface_path.pci.bus = PCI_BUS ( desc->location );
dpi->interface_path.pci.slot = PCI_SLOT ( desc->location );
dpi->interface_path.pci.function = PCI_FUNC ( desc->location );
dpi->interface_path.pci.channel = 0xff; /* unused */
break;
default:
DBGC ( sandev->drive, "INT13 drive %02x unrecognised bus "
"type %d\n", sandev->drive, desc->bus_type );
return -ENOTSUP;
}
/* Get EDD block device description */
if ( ( rc = edd_describe ( &sanpath->block, &dpi->interface_type,
&dpi->device_path ) ) != 0 ) {
DBGC ( sandev->drive, "INT13 drive %02x cannot identify "
"block device: %s\n", sandev->drive, strerror ( rc ) );
return rc;
}
/* Fill in common fields and fix checksum */
dpi->key = EDD_DEVICE_PATH_INFO_KEY;
dpi->len = sizeof ( *dpi );
for ( i = 0 ; i < sizeof ( *dpi ) ; i++ )
sum += *( ( ( uint8_t * ) dpi ) + i );
dpi->checksum -= sum;
return 0;
}
/**
* INT 13, 48 - Get extended parameters
*
* @v sandev SAN device
* @v ds:si Drive parameter table
* @ret status Status code
*/
static int int13_get_extended_parameters ( struct san_device *sandev,
struct i386_all_regs *ix86 ) {
struct int13_data *int13 = sandev->priv;
struct int13_disk_parameters params;
struct segoff address;
size_t len = sizeof ( params );
uint16_t bufsize;
int rc;
/* Get buffer size */
get_real ( bufsize, ix86->segs.ds,
( ix86->regs.si + offsetof ( typeof ( params ), bufsize )));
DBGC2 ( sandev->drive, "Get extended drive parameters to "
"%04x:%04x+%02x\n", ix86->segs.ds, ix86->regs.si, bufsize );
/* Build drive parameters */
memset ( ¶ms, 0, sizeof ( params ) );
params.flags = INT13_FL_DMA_TRANSPARENT;
if ( ( int13->cylinders < 1024 ) &&
( sandev_capacity ( sandev ) <= INT13_MAX_CHS_SECTORS ) ) {
params.flags |= INT13_FL_CHS_VALID;
}
params.cylinders = int13->cylinders;
params.heads = int13->heads;
params.sectors_per_track = int13->sectors_per_track;
params.sectors = sandev_capacity ( sandev );
params.sector_size = sandev_blksize ( sandev );
memset ( ¶ms.dpte, 0xff, sizeof ( params.dpte ) );
if ( ( rc = int13_device_path_info ( sandev, ¶ms.dpi ) ) != 0 ) {
DBGC ( sandev->drive, "INT13 drive %02x could not provide "
"device path information: %s\n",
sandev->drive, strerror ( rc ) );
len = offsetof ( typeof ( params ), dpi );
}
/* Calculate returned "buffer size" (which will be less than
* the length actually copied if device path information is
* present).
*/
if ( bufsize < offsetof ( typeof ( params ), dpte ) )
return -INT13_STATUS_INVALID;
if ( bufsize < offsetof ( typeof ( params ), dpi ) ) {
params.bufsize = offsetof ( typeof ( params ), dpte );
} else {
params.bufsize = offsetof ( typeof ( params ), dpi );
}
DBGC ( sandev->drive, "INT 13 drive %02x described using extended "
"parameters:\n", sandev->drive );
address.segment = ix86->segs.ds;
address.offset = ix86->regs.si;
DBGC_HDA ( sandev->drive, address, ¶ms, len );
/* Return drive parameters */
if ( len > bufsize )
len = bufsize;
copy_to_real ( ix86->segs.ds, ix86->regs.si, ¶ms, len );
return 0;
}
/**
* INT 13, 4b - Get status or terminate CD-ROM emulation
*
* @v sandev SAN device
* @v ds:si Specification packet
* @ret status Status code