int13.h File Reference

INT 13 emulation. More...

#include <stdint.h>
#include <gpxe/list.h>
#include <realmode.h>

Go to the source code of this file.

Data Structures

struct  int13_drive
 An INT 13 emulated drive. More...
struct  int13_disk_address
 An INT 13 disk address packet. More...
struct  int13_disk_parameters
 INT 13 disk parameters. More...
struct  int13_cdrom_specification
 Bootable CD-ROM specification packet. More...
struct  partition_chs
 A C/H/S address within a partition table entry. More...
struct  partition_table_entry
 A partition table entry within the MBR. More...
struct  master_boot_record
 A Master Boot Record. More...

Defines

#define INT13_RESET   0x00
 Reset disk system.
#define INT13_GET_LAST_STATUS   0x01
 Get status of last operation.
#define INT13_READ_SECTORS   0x02
 Read sectors.
#define INT13_WRITE_SECTORS   0x03
 Write sectors.
#define INT13_GET_PARAMETERS   0x08
 Get drive parameters.
#define INT13_GET_DISK_TYPE   0x15
 Get disk type.
#define INT13_EXTENSION_CHECK   0x41
 Extensions installation check.
#define INT13_EXTENDED_READ   0x42
 Extended read.
#define INT13_EXTENDED_WRITE   0x43
 Extended write.
#define INT13_GET_EXTENDED_PARAMETERS   0x48
 Get extended drive parameters.
#define INT13_CDROM_STATUS_TERMINATE   0x4b
 Get CD-ROM status / terminate emulation.
#define INT13_STATUS_SUCCESS   0x00
 Operation completed successfully.
#define INT13_STATUS_INVALID   0x01
 Invalid function or parameter.
#define INT13_STATUS_READ_ERROR   0x04
 Read error.
#define INT13_STATUS_WRITE_ERROR   0xcc
 Write error.
#define INT13_BLKSIZE   512
 Block size for non-extended INT 13 calls.
#define INT13_DISK_TYPE_NONE   0x00
 No such drive.
#define INT13_DISK_TYPE_FDD   0x01
 Floppy without change-line support.
#define INT13_DISK_TYPE_FDD_CL   0x02
 Floppy with change-line support.
#define INT13_DISK_TYPE_HDD   0x03
 Hard disk.
#define INT13_FL_DMA_TRANSPARENT   0x01
 DMA boundary errors handled transparently.
#define INT13_FL_CHS_VALID   0x02
 CHS information is valid.
#define INT13_FL_REMOVABLE   0x04
 Removable drive.
#define INT13_FL_VERIFIABLE   0x08
 Write with verify supported.
#define INT13_FL_CHANGE_LINE   0x10
 Has change-line supported (valid only for removable drives).
#define INT13_FL_LOCKABLE   0x20
 Drive can be locked (valid only for removable drives).
#define INT13_FL_CHS_MAX   0x40
 CHS is max possible, not current media (valid only for removable drives).
#define INT13_EXTENSION_LINEAR   0x01
 Extended disk access functions supported.
#define INT13_EXTENSION_REMOVABLE   0x02
 Removable drive functions supported.
#define INT13_EXTENSION_EDD   0x04
 EDD functions supported.
#define INT13_EXTENSION_VER_1_X   0x01
 INT13 extensions version 1.x.
#define INT13_EXTENSION_VER_2_0   0x20
 INT13 extensions version 2.0 (EDD-1.0).
#define INT13_EXTENSION_VER_2_1   0x21
 INT13 extensions version 2.1 (EDD-1.1).
#define INT13_EXTENSION_VER_3_0   0x30
 INT13 extensions version 3.0 (EDD-3.0).
#define PART_HEAD(chs)   ( (chs).head )
#define PART_SECTOR(chs)   ( (chs).cyl_sector & 0x3f )
#define PART_CYLINDER(chs)   ( (chs).cyl | ( ( (chs).cyl_sector & 0xc0 ) << 2 ) )

Functions

 FILE_LICENCE (GPL2_OR_LATER)
void register_int13_drive (struct int13_drive *drive)
 Register INT 13 emulated drive.
void unregister_int13_drive (struct int13_drive *drive)
 Unregister INT 13 emulated drive.
int int13_boot (unsigned int drive)
 Attempt to boot from an INT 13 drive.

Variables

struct int13_disk_address packed
 An INT 13 disk address packet.

Detailed Description

INT 13 emulation.

Definition in file int13.h.

Define Documentation

#define INT13_BLKSIZE   512

Block size for non-extended INT 13 calls.

Definition at line 65 of file int13.h.

Referenced by guess_int13_geometry(), and int13_rw_sectors().

#define PART_HEAD ( chs   )     ( (chs).head )

Definition at line 259 of file int13.h.

Referenced by guess_int13_geometry().

#define PART_SECTOR ( chs   )     ( (chs).cyl_sector & 0x3f )

Definition at line 260 of file int13.h.

Referenced by guess_int13_geometry().

#define PART_CYLINDER ( chs   )     ( (chs).cyl | ( ( (chs).cyl_sector & 0xc0 ) << 2 ) )

Definition at line 261 of file int13.h.

Function Documentation

FILE_LICENCE ( GPL2_OR_LATER   ) 

void register_int13_drive ( struct int13_drive *  drive  ) 

Register INT 13 emulated drive.

Parameters:
drive Emulated drive
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.

Definition at line 594 of file int13.c.

References BDA_NUM_DRIVES, BDA_SEG, int13_drive::cylinders, DBG, int13_drive::drive, get_real, guess_int13_geometry(), int13_drive::heads, hook_int13(), int13_set_num_drives(), int13_drive::list, list_add, list_empty(), int13_drive::natural_drive, num_drives, and int13_drive::sectors_per_track.

Referenced by aoeboot(), eltorito_exec(), ib_srpboot(), and iscsiboot().

00594                                                         {
00595         uint8_t num_drives;
00596 
00597         /* Give drive a default geometry if none specified */
00598         guess_int13_geometry ( drive );
00599 
00600         /* Assign natural drive number */
00601         get_real ( num_drives, BDA_SEG, BDA_NUM_DRIVES );
00602         drive->natural_drive = ( num_drives | 0x80 );
00603 
00604         /* Assign drive number */
00605         if ( ( drive->drive & 0xff ) == 0xff ) {
00606                 /* Drive number == -1 => use natural drive number */
00607                 drive->drive = drive->natural_drive;
00608         } else {
00609                 /* Use specified drive number (+0x80 if necessary) */
00610                 drive->drive |= 0x80;
00611         }
00612 
00613         DBG ( "Registered INT13 drive %02x (naturally %02x) with C/H/S "
00614               "geometry %d/%d/%d\n", drive->drive, drive->natural_drive,
00615               drive->cylinders, drive->heads, drive->sectors_per_track );
00616 
00617         /* Hook INT 13 vector if not already hooked */
00618         if ( list_empty ( &drives ) )
00619                 hook_int13();
00620 
00621         /* Add to list of emulated drives */
00622         list_add ( &drive->list, &drives );
00623 
00624         /* Update BIOS drive count */
00625         int13_set_num_drives();
00626 }

void unregister_int13_drive ( struct int13_drive *  drive  ) 

Unregister INT 13 emulated drive.

Parameters:
drive Emulated drive
Unregisters the drive from the INT 13 emulation subsystem. If this is the last emulated drive, the INT 13 vector is unhooked (if possible).

Definition at line 637 of file int13.c.

References DBG, int13_drive::drive, int13_drive::list, list_del, list_empty(), and unhook_int13().

Referenced by aoeboot(), eltorito_exec(), ib_srpboot(), and iscsiboot().

00637                                                           {
00638         /* Remove from list of emulated drives */
00639         list_del ( &drive->list );
00640 
00641         /* Should adjust BIOS drive count, but it's difficult to do so
00642          * reliably.
00643          */
00644 
00645         DBG ( "Unregistered INT13 drive %02x\n", drive->drive );
00646 
00647         /* Unhook INT 13 vector if no more drives */
00648         if ( list_empty ( &drives ) )
00649                 unhook_int13();
00650 }

int int13_boot ( unsigned int  drive  ) 

Attempt to boot from an INT 13 drive.

Parameters:
drive Drive number
Return values:
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.

Definition at line 665 of file int13.c.

References __asm__(), be16_to_cpu, call_bootsector(), cpu_to_be16, DBG, ECANCELED, EIO, ENOEXEC, get_memmap(), REAL_CODE, and strerror().

Referenced by aoeboot(), ib_srpboot(), and iscsiboot().

00665                                       {
00666         struct memory_map memmap;
00667         int status, signature;
00668         int discard_c, discard_d;
00669         int rc;
00670 
00671         DBG ( "Booting from INT 13 drive %02x\n", drive );
00672 
00673         /* Use INT 13 to read the boot sector */
00674         __asm__ __volatile__ ( REAL_CODE ( "pushw %%es\n\t"
00675                                            "pushw $0\n\t"
00676                                            "popw %%es\n\t"
00677                                            "stc\n\t"
00678                                            "sti\n\t"
00679                                            "int $0x13\n\t"
00680                                            "sti\n\t" /* BIOS bugs */
00681                                            "jc 1f\n\t"
00682                                            "xorl %%eax, %%eax\n\t"
00683                                            "\n1:\n\t"
00684                                            "movzwl %%es:0x7dfe, %%ebx\n\t"
00685                                            "popw %%es\n\t" )
00686                                : "=a" ( status ), "=b" ( signature ),
00687                                  "=c" ( discard_c ), "=d" ( discard_d )
00688                                : "a" ( 0x0201 ), "b" ( 0x7c00 ),
00689                                  "c" ( 1 ), "d" ( drive ) );
00690         if ( status )
00691                 return -EIO;
00692 
00693         /* Check signature is correct */
00694         if ( signature != be16_to_cpu ( 0x55aa ) ) {
00695                 DBG ( "Invalid disk signature %#04x (should be 0x55aa)\n",
00696                       cpu_to_be16 ( signature ) );
00697                 return -ENOEXEC;
00698         }
00699 
00700         /* Dump out memory map prior to boot, if memmap debugging is
00701          * enabled.  Not required for program flow, but we have so
00702          * many problems that turn out to be memory-map related that
00703          * it's worth doing.
00704          */
00705         get_memmap ( &memmap );
00706 
00707         /* Jump to boot sector */
00708         if ( ( rc = call_bootsector ( 0x0, 0x7c00, drive ) ) != 0 ) {
00709                 DBG ( "INT 13 drive %02x boot returned: %s\n",
00710                       drive, strerror ( rc ) );
00711                 return rc;
00712         }
00713 
00714         return -ECANCELED; /* -EIMPOSSIBLE */
00715 }

Variable Documentation

struct master_boot_record packed

An INT 13 disk address packet.

A Master Boot Record.

A partition table entry within the MBR.

A C/H/S address within a partition table entry.

Bootable CD-ROM specification packet.

INT 13 disk parameters.

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