source: mainline/uspace/lib/mbr/libmbr.h@ 271e24a

/*
 * Copyright (c) 2011, 2012, 2013 Dominik Taborsky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

 /** @addtogroup libmbr
 * @{
 */
/** @file
 */

#ifndef LIBMBR_LIBMBR_H_
#define LIBMBR_LIBMBR_H_

#include <sys/types.h>

#define LIBMBR_NAME     "libmbr"

/** Number of primary partition records */
#define N_PRIMARY               4

/** Boot record signature */
#define BR_SIGNATURE    0xAA55

enum {
        /** Non-bootable */
        B_INACTIVE = 0x00,
        /** Bootable */
        B_ACTIVE = 0x80,
        /** Anything else means invalid */
};

typedef enum {
        /** Bootability */
        ST_BOOT = 0,
        /** Logical partition, 0 = primary, 1 = logical*/
        ST_LOGIC = 1
} MBR_FLAGS;

enum {
        /** Unused partition entry */
        PT_UNUSED       = 0x00,
        /** Extended partition */
        PT_EXTENDED     = 0x05,
        /** GPT Protective partition */
        PT_GPT  = 0xEE,
};

/** Structure of a partition table entry */
typedef struct {
        uint8_t status;
        /** CHS of fist block in partition */
        uint8_t first_chs[3];
        /** Partition type */
        uint8_t ptype;
        /** CHS of last block in partition */
        uint8_t last_chs[3];
        /** LBA of first block in partition */
        uint32_t first_lba;
        /** Number of blocks in partition */
        uint32_t length;
} __attribute__((packed)) pt_entry_t;

/** Structure of a boot-record block */
typedef struct {
        /** Area for boot code */
        uint8_t code_area[440];
        /** Optional media ID */
        uint32_t media_id;
        /** Padding */
        uint16_t pad0;
        /** Partition table entries */
        pt_entry_t pte[N_PRIMARY];
        /** Boot record block signature (@c BR_SIGNATURE) */
        uint16_t signature;
} __attribute__((packed)) br_block_t;

/** MBR header */
typedef struct {
        /** Raw access to data */
        br_block_t raw_data;
        /** Device where the data are from */
        service_id_t device;
        /** Pointer to partition list */
        //list of partitions;   //if we keep this in here, we should free() it in mbr_free_mbr()
} mbr_t;


//FIXME: make mbr_partitions_t as the linked list for keeping the same interface as with GPT
/** Partition */
typedef struct mbr_part {
        /** The link in the doubly-linked list */
        link_t link;
        /** Partition type */
        uint8_t type;
        /** Flags */
        uint8_t status;
        /** Address of first block */
        uint32_t start_addr;
        /** Number of blocks */
        uint32_t length;
        /** Points to Extended Boot Record of logical partition */
        br_block_t * ebr;
} mbr_part_t;

typedef struct mbr_parts {
        /** Number of primary partitions */
        unsigned char n_primary;
        /** Link to the extended partition in the list */
        link_t * l_extended;
        /** Number of logical partitions */
        unsigned int n_logical;
        /** Partition linked list */
        list_t list;
} mbr_partitions_t;

typedef struct mbr_table {
        mbr_t * mbr;
        mbr_partitions_t * parts;
} mbr_table_t;

/** Read/Write MBR header.
 * WARNING: when changing both header and partitions, write first header,
 * then partitions. The MBR headers' raw_data is NOT updated to follow
 * partition changes. */
extern mbr_t * mbr_read_mbr(service_id_t dev_handle);
extern int mbr_write_mbr(mbr_t * mbr, service_id_t dev_handle);
extern int mbr_is_mbr(mbr_t * mbr);

/** Read/Write/Set MBR partitions. */
extern mbr_partitions_t * mbr_read_partitions(mbr_t * mbr);
extern int                      mbr_write_partitions(mbr_partitions_t * parts, mbr_t * mbr, service_id_t dev_handle);
extern mbr_part_t *     mbr_alloc_partition(void);
extern mbr_partitions_t * mbr_alloc_partitions(void);
extern int                      mbr_add_partition(mbr_partitions_t * parts, mbr_part_t * partition);
extern int                      mbr_remove_partition(mbr_partitions_t * parts, size_t idx);
extern int                      mbr_get_flag(mbr_part_t * p, MBR_FLAGS flag);
extern void                     mbr_set_flag(mbr_part_t * p, MBR_FLAGS flag, bool value);

#define mbr_part_foreach(parts, iterator)       \
                        for (mbr_part_t * iterator = list_get_instance((parts)->list.head.next, mbr_part_t, link); \
                                iterator != list_get_instance(&(parts)->list.head, mbr_part_t, link); \
                                iterator = list_get_instance(iterator->link.next, mbr_part_t, link))


/** free() wrapper functions. */
extern void mbr_free_mbr(mbr_t * mbr);
extern void mbr_free_partition(mbr_part_t * p);
extern void mbr_free_partitions(mbr_partitions_t * parts);

#endif