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#ifndef INT13_H
#define INT13_H
/** @file
*
* INT 13 emulation
*
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <stdint.h>
#include <gpxe/list.h>
#include <realmode.h>
struct block_device;
/**
* @defgroup int13ops INT 13 operation codes
* @{
*/
/** Reset disk system */
#define INT13_RESET 0x00
/** Get status of last operation */
#define INT13_GET_LAST_STATUS 0x01
/** Read sectors */
#define INT13_READ_SECTORS 0x02
/** Write sectors */
#define INT13_WRITE_SECTORS 0x03
/** Get drive parameters */
#define INT13_GET_PARAMETERS 0x08
/** Get disk type */
#define INT13_GET_DISK_TYPE 0x15
/** Extensions installation check */
#define INT13_EXTENSION_CHECK 0x41
/** Extended read */
#define INT13_EXTENDED_READ 0x42
/** Extended write */
#define INT13_EXTENDED_WRITE 0x43
/** Get extended drive parameters */
#define INT13_GET_EXTENDED_PARAMETERS 0x48
/** Get CD-ROM status / terminate emulation */
#define INT13_CDROM_STATUS_TERMINATE 0x4b
/** @} */
/**
* @defgroup int13status INT 13 status codes
* @{
*/
/** Operation completed successfully */
#define INT13_STATUS_SUCCESS 0x00
/** Invalid function or parameter */
#define INT13_STATUS_INVALID 0x01
/** Read error */
#define INT13_STATUS_READ_ERROR 0x04
/** Write error */
#define INT13_STATUS_WRITE_ERROR 0xcc
/** @} */
/** Block size for non-extended INT 13 calls */
#define INT13_BLKSIZE 512
/** An INT 13 emulated drive */
struct int13_drive {
/** List of all registered drives */
struct list_head list;
/** Underlying block device */
struct block_device *blockdev;
/** 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;
/** 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;
/** Status of last operation */
int last_status;
};
/** An INT 13 disk address packet */
struct int13_disk_address {
/** Size of the packet, in bytes */
uint8_t bufsize;
/** Reserved, must be zero */
uint8_t reserved;
/** Block count */
uint16_t count;
/** Data buffer */
struct segoff buffer;
/** Starting block number */
uint64_t lba;
/** Data buffer (EDD-3.0 only) */
uint64_t buffer_phys;
} __attribute__ (( packed ));
/** INT 13 disk parameters */
struct int13_disk_parameters {
/** Size of this structure */
uint16_t bufsize;
/** Flags */
uint16_t flags;
/** Number of cylinders */
uint32_t cylinders;
/** Number of heads */
uint32_t heads;
/** Number of sectors per track */
uint32_t sectors_per_track;
/** Total number of sectors on drive */
uint64_t sectors;
/** Bytes per sector */
uint16_t sector_size;
} __attribute__ (( packed ));
/**
* @defgroup int13types INT 13 disk types
* @{
*/
/** No such drive */
#define INT13_DISK_TYPE_NONE 0x00
/** Floppy without change-line support */
#define INT13_DISK_TYPE_FDD 0x01
/** Floppy with change-line support */
#define INT13_DISK_TYPE_FDD_CL 0x02
/** Hard disk */
#define INT13_DISK_TYPE_HDD 0x03
/** @} */
/**
* @defgroup int13flags INT 13 disk parameter flags
* @{
*/
/** DMA boundary errors handled transparently */
#define INT13_FL_DMA_TRANSPARENT 0x01
/** CHS information is valid */
#define INT13_FL_CHS_VALID 0x02
/** Removable drive */
#define INT13_FL_REMOVABLE 0x04
/** Write with verify supported */
#define INT13_FL_VERIFIABLE 0x08
/** Has change-line supported (valid only for removable drives) */
#define INT13_FL_CHANGE_LINE 0x10
/** Drive can be locked (valid only for removable drives) */
#define INT13_FL_LOCKABLE 0x20
/** CHS is max possible, not current media (valid only for removable drives) */
#define INT13_FL_CHS_MAX 0x40
/** @} */
/**
* @defgroup int13exts INT 13 extension flags
* @{
*/
/** Extended disk access functions supported */
#define INT13_EXTENSION_LINEAR 0x01
/** Removable drive functions supported */
#define INT13_EXTENSION_REMOVABLE 0x02
/** EDD functions supported */
#define INT13_EXTENSION_EDD 0x04
/** @} */
/**
* @defgroup int13vers INT 13 extension versions
* @{
*/
/** INT13 extensions version 1.x */
#define INT13_EXTENSION_VER_1_X 0x01
/** INT13 extensions version 2.0 (EDD-1.0) */
#define INT13_EXTENSION_VER_2_0 0x20
/** INT13 extensions version 2.1 (EDD-1.1) */
#define INT13_EXTENSION_VER_2_1 0x21
/** INT13 extensions version 3.0 (EDD-3.0) */
#define INT13_EXTENSION_VER_3_0 0x30
/** @} */
/** Bootable CD-ROM specification packet */
struct int13_cdrom_specification {
/** Size of packet in bytes */
uint8_t size;
/** Boot media type */
uint8_t media_type;
/** Drive number */
uint8_t drive;
/** CD-ROM controller number */
uint8_t controller;
/** LBA of disk image to emulate */
uint32_t lba;
/** Device specification */
uint16_t device;
/** Segment of 3K buffer for caching CD-ROM reads */
uint16_t cache_segment;
/** Load segment for initial boot image */
uint16_t load_segment;
/** Number of 512-byte sectors to load */
uint16_t load_sectors;
/** Low 8 bits of cylinder number */
uint8_t cyl;
/** Sector number, plus high 2 bits of cylinder number */
uint8_t cyl_sector;
/** Head number */
uint8_t head;
} __attribute__ (( packed ));
/** A C/H/S address within a partition table entry */
struct partition_chs {
/** Head number */
uint8_t head;
/** Sector number, plus high 2 bits of cylinder number */
uint8_t cyl_sector;
/** Low 8 bits of cylinder number */
uint8_t cyl;
} __attribute__ (( packed ));
#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 ) )
/** A partition table entry within the MBR */
struct partition_table_entry {
/** Bootable flag */
uint8_t bootable;
/** C/H/S start address */
struct partition_chs chs_start;
/** System indicator (partition type) */
uint8_t type;
/** C/H/S end address */
struct partition_chs chs_end;
/** Linear start address */
uint32_t start;
/** Linear length */
uint32_t length;
} __attribute__ (( packed ));
/** A Master Boot Record */
struct master_boot_record {
uint8_t pad[446];
/** Partition table */
struct partition_table_entry partitions[4];
/** 0x55aa MBR signature */
uint16_t signature;
} __attribute__ (( packed ));
extern void register_int13_drive ( struct int13_drive *drive );
extern void unregister_int13_drive ( struct int13_drive *drive );
extern int int13_boot ( unsigned int drive );
#endif /* INT13_H */
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