source: bootcd/isolinux/syslinux-6.03/com32/include/syslinux/disk.h

/* ----------------------------------------------------------------------- *
 *
 *   Copyright 2003-2009 H. Peter Anvin - All Rights Reserved
 *   Copyright 2009-2010 Intel Corporation; author: H. Peter Anvin
 *   Copyright (C) 2010 Shao Miller
 *
 *   Permission is hereby granted, free of charge, to any person
 *   obtaining a copy of this software and associated documentation
 *   files (the "Software"), to deal in the Software without
 *   restriction, including without limitation the rights to use,
 *   copy, modify, merge, publish, distribute, sublicense, and/or
 *   sell copies of the Software, and to permit persons to whom
 *   the Software is furnished to do so, subject to the following
 *   conditions:
 *
 *   The above copyright notice and this permission notice shall
 *   be included in all copies or substantial portions of the Software.
 *
 *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 *   OTHER DEALINGS IN THE SOFTWARE.
 *
 * ----------------------------------------------------------------------- */

/**
 * @file syslinux/disk.h
 *
 * Deal with disks and partitions
 */

#ifndef _SYSLINUX_DISK_H
#define _SYSLINUX_DISK_H

#include <com32.h>
#include <stdint.h>

#define SECTOR 512u             /* bytes/sector */

enum disk_op_codes {
    EBIOS_READ_CODE = 0x42, /* Extended read */
    EBIOS_WRITE_CODE = 0x43, /* Extended write */
    CHS_READ_CODE = 0x02,
    CHS_WRITE_CODE = 0x03,
};

struct disk_info {
    int disk;
    int ebios;                  /* EBIOS supported on this disk */
    int cbios;                  /* CHS geometry is valid */
    uint32_t bps;               /* bytes per sector */
    uint64_t lbacnt;            /* total amount of sectors */
    uint32_t cyl;
    uint32_t head;
    uint32_t spt;
};

struct disk_ebios_dapa {
    uint16_t len;
    uint16_t count;
    uint16_t off;
    uint16_t seg;
    uint64_t lba;
} __attribute__ ((packed));

struct disk_ebios_eparam {
    uint16_t len;
    uint16_t info;
    uint32_t cyl;
    uint32_t head;
    uint32_t spt;
    uint64_t lbacnt;
    uint16_t bps;       /* bytes per sector */
    uint32_t edd;
    uint16_t dpi_sig;
    uint8_t  dpi_len;
    char     reserved1[3];
    char     hostbus[4];
    char     if_type[8];
    char     if_path[8];
    char     dev_path[8];
    char     reserved2;
    uint8_t  checksum;
} __attribute__ ((packed));

/**
 * CHS (cylinder, head, sector) value extraction macros.
 * Taken from WinVBlock.  None expand to an lvalue.
*/
#define     chs_head(chs) chs[0]
#define   chs_sector(chs) (chs[1] & 0x3F)
#define chs_cyl_high(chs) (((uint16_t)(chs[1] & 0xC0)) << 2)
#define  chs_cyl_low(chs) ((uint16_t)chs[2])
#define chs_cylinder(chs) (chs_cyl_high(chs) | chs_cyl_low(chs))
typedef uint8_t disk_chs[3];

/* A DOS partition table entry */
struct disk_dos_part_entry {
    uint8_t active_flag;        /* 0x80 if "active" */
    disk_chs start;
    uint8_t ostype;
    disk_chs end;
    uint32_t start_lba;
    uint32_t length;
} __attribute__ ((packed));

/* A DOS MBR */
struct disk_dos_mbr {
    char code[440];
    uint32_t disk_sig;
    char pad[2];
    struct disk_dos_part_entry table[4];
    uint16_t sig;
} __attribute__ ((packed));
#define disk_mbr_sig_magic 0xAA55

/**
 * A GPT disk/partition GUID
 *
 * Be careful with endianness, you must adjust it yourself
 * iff you are directly using the fourth data chunk.
 * There might be a better header for this...
 */
struct guid {
    uint32_t data1;
    uint16_t data2;
    uint16_t data3;
    uint64_t data4;
} __attribute__ ((packed));

/* A GPT partition */
struct disk_gpt_part_entry {
    struct guid type;
    struct guid uid;
    uint64_t lba_first;
    uint64_t lba_last;
    uint64_t attribs;
    char name[72];
} __attribute__ ((packed));

/* A GPT header */
struct disk_gpt_header {
    char sig[8];
    union {
        struct {
            uint16_t minor;
            uint16_t major;
        } fields __attribute__ ((packed));
        uint32_t uint32;
        char raw[4];
    } rev __attribute__ ((packed));
    uint32_t hdr_size;
    uint32_t chksum;
    char reserved1[4];
    uint64_t lba_cur;
    uint64_t lba_alt;
    uint64_t lba_first_usable;
    uint64_t lba_last_usable;
    struct guid disk_guid;
    uint64_t lba_table;
    uint32_t part_count;
    uint32_t part_size;
    uint32_t table_chksum;
    char reserved2[1];
} __attribute__ ((packed));
static const char disk_gpt_sig_magic[] = "EFI PART";

extern int disk_int13_retry(const com32sys_t * inreg, com32sys_t * outreg);
extern int disk_get_params(int disk, struct disk_info *const diskinfo);
extern void *disk_read_sectors(const struct disk_info *const diskinfo,
                               uint64_t lba, uint8_t count);
extern int disk_write_sectors(const struct disk_info *const diskinfo,
                              uint64_t lba, const void *data, uint8_t count);
extern int disk_write_verify_sectors(const struct disk_info *const diskinfo,
                                     uint64_t lba, const void *buf, uint8_t count);
extern void disk_dos_part_dump(const struct disk_dos_part_entry *const part);
extern void guid_to_str(char *buf, const struct guid *const id);
extern int str_to_guid(const char *buf, struct guid *const id);
extern void disk_gpt_part_dump(const struct disk_gpt_part_entry *const
                               gpt_part);
extern void disk_gpt_header_dump(const struct disk_gpt_header *const gpt);

#endif /* _SYSLINUX_DISK_H */