libisofs/libisofs/eltorito.h

/*
 * Copyright (c) 2007 Vreixo Formoso
 * Copyright (c) 2010 - 2014 Thomas Schmitt
 *
 * This file is part of the libisofs project; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version 2 
 * or later as published by the Free Software Foundation. 
 * See COPYING file for details.
 */

/**
 * Declare El-Torito related structures.
 * References:
 *  "El Torito" Bootable CD-ROM Format Specification Version 1.0 (1995)
 */

#ifndef LIBISO_ELTORITO_H
#define LIBISO_ELTORITO_H

#include "ecma119.h"
#include "node.h"

/**
 * A node that acts as a placeholder for an El-Torito catalog.
 */
struct Iso_Boot
{
    IsoNode node;

    /* Want to get content of loaded boot catalog.
       Vreixo took care not to make it an IsoFile at load time.
       So this is implemented independently of IsoStream.
     */
    uint32_t lba;
    off_t size;
    char *content;
};

/* Not more than 32 so that all entries fit into 2048 bytes */
#define Libisofs_max_boot_imageS 32

struct el_torito_boot_catalog {
    IsoBoot *node; /* node of the catalog */

    int num_bootimages;
    struct el_torito_boot_image *bootimages[Libisofs_max_boot_imageS];
                                                  /* [0]= default boot image */

    /* Weight value for image sorting */
    int sort_weight;
};

struct el_torito_boot_image {
    IsoFile *image;

    /* Overrides .image if >= 0 : array index of appended partition */
    int appended_idx;
    uint32_t appended_start; /* In blocks of 2048 bytes */
    uint32_t appended_size;  /* In blocks of  512 bytes */

    unsigned int bootable:1; /**< If the entry is bootable. */
    /**
     * Whether the boot image seems to contain a boot_info_table
     */
    unsigned int seems_boot_info_table:1;
    unsigned int seems_grub2_boot_info:1;
    /**
     * Whether the boot image seems to be capable of isohybrid
     */
    unsigned int seems_isohybrid_capable:1;
    /**
     * isolinux options
     * bit 0 -> whether to patch image
     * bit 1 -> whether to put built-in isolinux 3.72 isohybrid-MBR into image
     *          System Area (deprecated)
     *
     *  bit2-7= Mentioning in isohybrid GPT
     *          0= do not mention in GPT
     *          1= mention as EFI partition
     *          2= Mention as HFS+ partition
     *  bit8= Mention in isohybrid Apple partition map
     */
    unsigned int isolinux_options;
    unsigned char type; /**< The type of image */
    unsigned char partition_type; /**< type of partition for HD-emul images */
    uint16_t load_seg; /**< Load segment for the initial boot image. */
    uint16_t load_size; /**< Number of sectors to load. */

    /* Byte 1 of Validation Entry or Section Header Entry:
       0= 80x86, 1= PowerPC, 2= Mac, 0xef= EFI */
    uint8_t platform_id;
    uint8_t id_string[28];
    uint8_t selection_crit[20];

};

/** El-Torito, 2.1 */
struct el_torito_validation_entry {
    uint8_t header_id           BP(1, 1);
    uint8_t platform_id         BP(2, 2);
    uint8_t reserved            BP(3, 4);
    uint8_t id_string           BP(5, 28);
    uint8_t checksum            BP(29, 30);
    uint8_t key_byte1           BP(31, 31);
    uint8_t key_byte2           BP(32, 32);
};

/** El-Torito, 2.2 */
struct el_torito_default_entry {
    uint8_t boot_indicator      BP(1, 1);
    uint8_t boot_media_type     BP(2, 2);
    uint8_t load_seg            BP(3, 4);
    uint8_t system_type         BP(5, 5);
    uint8_t unused1             BP(6, 6);
    uint8_t sec_count           BP(7, 8);
    uint8_t block               BP(9, 12);
    uint8_t unused2             BP(13, 32);
};

/** El-Torito, 2.3 */
struct el_torito_section_header {
    uint8_t header_indicator    BP(1, 1);
    uint8_t platform_id         BP(2, 2);
    uint8_t num_entries         BP(3, 4);
    uint8_t id_string           BP(5, 32);
};

/** El-Torito, 2.4 */
struct el_torito_section_entry {
    uint8_t boot_indicator      BP(1, 1);
    uint8_t boot_media_type     BP(2, 2);
    uint8_t load_seg            BP(3, 4);
    uint8_t system_type         BP(5, 5);
    uint8_t unused1             BP(6, 6);
    uint8_t sec_count           BP(7, 8);
    uint8_t block               BP(9, 12);
    uint8_t selec_criteria      BP(13, 13);
    uint8_t vendor_sc           BP(14, 32);
};

void el_torito_boot_catalog_free(struct el_torito_boot_catalog *cat);

/**
 * Create a IsoFileSrc for writing the el-torito catalog for the given
 * target, and add it to target. If the target already has a src for the
 * catalog, it just returns.
 */
int el_torito_catalog_file_src_create(Ecma119Image *target, IsoFileSrc **src);

/**
 * Create a writer for el-torito information.
 */
int eltorito_writer_create(Ecma119Image *target);

/**
 * Insert boot info table content into buf.
 *
 * @return
 *      1 on success, 0 error (but continue), < 0 error
 */
int make_boot_info_table(uint8_t *buf, uint32_t pvd_lba,
                         uint32_t boot_lba, uint32_t imgsize);

/* Patch the boot images if indicated.
*/
int iso_patch_eltoritos(Ecma119Image *t);


/* Parameters for patch_grub2_boot_image()
   Might later become variables in struct el_torito_boot_image.
*/
#define Libisofs_grub2_elto_patch_poS    (512 * 5 - 12)
#define Libisofs_grub2_elto_patch_offsT  5


/* Maximum size of a boot image which is marked by
   el_torito_set_isolinux_options() for patching (boot info table,
   GRUB2 boot info, maybe others).
*/
#define Libisofs_elto_max_patchablE      (32 * 1024 * 1024)


#endif /* LIBISO_ELTORITO_H */