libburnia/libisofs
2
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Add El-Torito estructures to an IsoImage, and APIs for manage it.

Browse Source
This commit is contained in:
Vreixo Formoso 2008-01-10 17:22:53 +01:00
parent 51df8c6284
commit 47bdbd76b5
11 changed files with 750 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Makefile.am
View File

@ -46,6 +46,8 @@ src_libisofs_la_SOURCES = \
src/rockridge_read.c \
src/joliet.h \
src/joliet.c \
src/eltorito.h \
src/eltorito.c \
src/data_source.c
libinclude_HEADERS = \
src/libisofs.h

510
src/eltorito.c Normal file
View File

@ -0,0 +1,510 @@
/*
* Copyright (c) 2007 Vreixo Formoso
*
* 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 as
* published by the Free Software Foundation. See COPYING file for details.
*/
#include "eltorito.h"
#include "stream.h"
#include "error.h"
#include "fsource.h"
#include "image.h"
#include "messages.h"
#include <stdlib.h>
#include <string.h>
/**
* This table should be written with accuracy values at offset
* 8 of boot image, when used ISOLINUX boot loader
*/
struct boot_info_table {
uint8_t bi_pvd BP(1, 4); /* LBA of primary volume descriptor */
uint8_t bi_file BP(5, 8); /* LBA of boot file */
uint8_t bi_length BP(9, 12); /* Length of boot file */
uint8_t bi_csum BP(13, 16); /* Checksum of boot file */
uint8_t bi_reserved BP(17, 56); /* Reserved */
};
/**
* Structure for each one of the four entries in a partition table on a
* hard disk image.
*/
struct partition_desc {
uint8_t boot_ind;
uint8_t begin_chs[3];
uint8_t type;
uint8_t end_chs[3];
uint8_t start[4];
uint8_t size[4];
};
/**
* Structures for a Master Boot Record of a hard disk image.
*/
struct hard_disc_mbr {
uint8_t code_area[440];
uint8_t opt_disk_sg[4];
uint8_t pad[2];
struct partition_desc partition[4];
uint8_t sign1;
uint8_t sign2;
};
/**
* Sets the load segment for the initial boot image. This is only for
* no emulation boot images, and is a NOP for other image types.
*/
void el_torito_set_load_seg(ElToritoBootImage *bootimg, short segment)
{
if (bootimg->type != ELTORITO_NO_EMUL)
return;
bootimg->load_seg = segment;
}
/**
* Sets the number of sectors (512b) to be load at load segment during
* the initial boot procedure. This is only for no emulation boot images,
* and is a NOP for other image types.
*/
void el_torito_set_load_size(ElToritoBootImage *bootimg, short sectors)
{
if (bootimg->type != ELTORITO_NO_EMUL)
return;
bootimg->load_size = sectors;
}
/**
* Marks the specified boot image as not bootable
*/
void el_torito_set_no_bootable(ElToritoBootImage *bootimg)
{
bootimg->bootable = 0;
}
/**
* Specifies that this image needs to be patched. This involves the writting
* of a 56 bytes boot information table at offset 8 of the boot image file.
* The original boot image file won't be modified.
* This is needed for isolinux boot images.
*/
void el_torito_patch_isolinux_image(ElToritoBootImage *bootimg)
{
bootimg->isolinux = 1;
}
static
int iso_tree_add_boot_node(IsoDir *parent, const char *name, IsoBoot **boot)
{
IsoBoot *node;
IsoNode **pos;
time_t now;
if (parent == NULL || name == NULL || boot == NULL) {
return ISO_NULL_POINTER;
}
if (boot) {
*boot = NULL;
}
/* check if the name is valid */
if (!iso_node_is_valid_name(name)) {
return ISO_WRONG_ARG_VALUE;
}
/* find place where to insert */
pos = &(parent->children);
while (*pos != NULL && strcmp((*pos)->name, name) < 0) {
pos = &((*pos)->next);
}
if (*pos != NULL && !strcmp((*pos)->name, name)) {
/* a node with same name already exists */
return ISO_NODE_NAME_NOT_UNIQUE;
}
node = calloc(1, sizeof(IsoBoot));
if (node == NULL) {
return ISO_MEM_ERROR;
}
node->node.refcount = 1;
node->node.type = LIBISO_BOOT;
node->node.name = strdup(name);
if (node->node.name == NULL) {
free(node);
return ISO_MEM_ERROR;
}
/* atributes from parent */
node->node.mode = S_IFREG | (parent->node.mode & 0444);
node->node.uid = parent->node.uid;
node->node.gid = parent->node.gid;
node->node.hidden = parent->node.hidden;
/* current time */
now = time(NULL);
node->node.atime = now;
node->node.ctime = now;
node->node.mtime = now;
node->msblock = 0;
/* add to dir */
node->node.parent = parent;
node->node.next = *pos;
*pos = (IsoNode*)node;
if (boot) {
*boot = node;
}
return ++parent->nchildren;
}
static
int create_image(IsoImage *image, const char *image_path,
enum eltorito_boot_media_type type,
struct el_torito_boot_image **bootimg)
{
int ret;
struct el_torito_boot_image *boot;
int boot_media_type = 0;
int load_sectors = 0; /* number of sector to load */
unsigned char partition_type = 0;
IsoNode *imgfile;
IsoStream *stream;
ret = iso_tree_path_to_node(image, image_path, &imgfile);
if (ret < 0) {
return ret;
}
if (ret == 0) {
return ISO_FILE_DOESNT_EXIST;
}
if (imgfile->type != LIBISO_FILE) {
return ISO_BOOT_IMAGE_NOT_VALID;
}
stream = ((IsoFile*)imgfile)->stream;
/* we need to read the image at least two times */
if (!iso_stream_is_repeatable(stream)) {
return ISO_BOOT_IMAGE_NOT_VALID;
}
switch (type) {
case ELTORITO_FLOPPY_EMUL:
switch (iso_stream_get_size(stream)) {
case 1200 * 1024:
boot_media_type = 1; /* 1.2 meg diskette */
break;
case 1440 * 1024:
boot_media_type = 2; /* 1.44 meg diskette */
break;
case 2880 * 1024:
boot_media_type = 3; /* 2.88 meg diskette */
break;
default:
iso_msg_sorry(image->messenger, LIBISO_EL_TORITO_WRONG_IMG,
"Invalid image size %d Kb. Must be one of 1.2, 1.44"
"or 2.88 Mb", iso_stream_get_size(stream) / 1024);
return ISO_BOOT_IMAGE_NOT_VALID;
break;
}
/* it seems that for floppy emulation we need to load
* a single sector (512b) */
load_sectors = 1;
break;
case ELTORITO_HARD_DISC_EMUL:
{
size_t i;
struct hard_disc_mbr mbr;
int used_partition;
/* read the MBR on disc and get the type of the partition */
ret = iso_stream_open(stream);
if (ret < 0) {
iso_msg_sorry(image->messenger, LIBISO_EL_TORITO_WRONG_IMG,
"Can't open image file.");
return ret;
}
ret = iso_stream_read(stream, &mbr, sizeof(mbr));
iso_stream_close(stream);
if (ret != sizeof(mbr)) {
iso_msg_sorry(image->messenger, LIBISO_EL_TORITO_WRONG_IMG,
"Can't read MBR from image file.");
return ret < 0 ? ret : ISO_FILE_READ_ERROR;
}
/* check valid MBR signature */
if ( mbr.sign1 != 0x55 || mbr.sign2 != 0xAA ) {
iso_msg_sorry(image->messenger, LIBISO_EL_TORITO_WRONG_IMG,
"Invalid MBR. Wrong signature.");
return ISO_BOOT_IMAGE_NOT_VALID;
}
/* ensure single partition */
used_partition = -1;
for (i = 0; i < 4; ++i) {
if (mbr.partition[i].type != 0) {
/* it's an used partition */
if (used_partition != -1) {
iso_msg_sorry(image->messenger, LIBISO_EL_TORITO_WRONG_IMG,
"Invalid MBR. At least 2 partitions: %d and "
"%d, are being used\n", used_partition, i);
return ISO_BOOT_IMAGE_NOT_VALID;
} else
used_partition = i;
}
}
partition_type = mbr.partition[used_partition].type;
}
boot_media_type = 4;
/* only load the MBR */
load_sectors = 1;
break;
case ELTORITO_NO_EMUL:
boot_media_type = 0;
break;
}
boot = calloc(1, sizeof(struct el_torito_boot_image));
if (boot == NULL) {
return ISO_MEM_ERROR;
}
boot->image = (IsoFile*)imgfile;
iso_node_ref(imgfile); /* get our ref */
boot->bootable = 1;
boot->type = boot_media_type;
boot->load_size = load_sectors;
boot->partition_type = partition_type;
if (bootimg) {
*bootimg = boot;
}
return ISO_SUCCESS;
}
int iso_image_set_boot_image(IsoImage *image, const char *image_path,
enum eltorito_boot_media_type type,
const char *catalog_path,
ElToritoBootImage **boot)
{
int ret;
struct el_torito_boot_catalog *catalog;
ElToritoBootImage *boot_image= NULL;
IsoBoot *cat_node= NULL;
if (image == NULL || image_path == NULL || catalog_path == NULL) {
return ISO_NULL_POINTER;
}
if (image->bootcat != NULL) {
return ISO_IMAGE_ALREADY_BOOTABLE;
}
/* create the node for the catalog */
{
IsoDir *parent;
char *catdir = NULL, *catname = NULL;
catdir = strdup(catalog_path);
if (catdir == NULL) {
return ISO_MEM_ERROR;
}
/* get both the dir and the name */
catname = strrchr(catdir, '/');
if (catname == NULL) {
free(catdir);
return ISO_WRONG_ARG_VALUE;
}
if (catname == catdir) {
/* we are apending catalog to root node */
parent = image->root;
} else {
IsoNode *p;
catname[0] = '\0';
ret = iso_tree_path_to_node(image, catdir, &p);
if (ret <= 0) {
free(catdir);
return ret < 0 ? ret : ISO_FILE_DOESNT_EXIST;
}
if (p->type != LIBISO_DIR) {
free(catdir);
return ISO_WRONG_ARG_VALUE;
}
parent = (IsoDir*)p;
}
catname++;
ret = iso_tree_add_boot_node(parent, catname, &cat_node);
free(catdir);
if (ret < 0) {
return ret;
}
}
/* create the boot image */
ret = create_image(image, image_path, type, &boot_image);
if (ret < 0) {
goto boot_image_cleanup;
}
/* creates the catalog with the given image */
catalog = malloc(sizeof(struct el_torito_boot_catalog));
if (catalog == NULL) {
ret = ISO_MEM_ERROR;
goto boot_image_cleanup;
}
catalog->image = boot_image;
catalog->node = cat_node;
iso_node_ref((IsoNode*)cat_node);
image->bootcat = catalog;
if (boot) {
*boot = boot_image;
}
return ISO_SUCCESS;
boot_image_cleanup:;
if (cat_node) {
iso_node_take((IsoNode*)cat_node);
iso_node_unref((IsoNode*)cat_node);
}
if (boot_image) {
iso_node_unref((IsoNode*)boot_image->image);
free(boot_image);
}
return ret;
}
/**
* Get El-Torito boot image of an ISO image, if any.
*
* This can be useful, for example, to check if a volume read from a previous
* session or an existing image is bootable. It can also be useful to get
* the image and catalog tree nodes. An application would want those, for
* example, to prevent the user removing it.
*
* Both nodes are owned by libisofs and should not be freed. You can get your
* own ref with iso_node_ref(). You can can also check if the node is already
* on the tree by getting its parent (note that when reading El-Torito info
* from a previous image, the nodes might not be on the tree even if you haven't
* removed them). Remember that you'll need to get a new ref
* (with iso_node_ref()) before inserting them again to the tree, and probably
* you will also need to set the name or permissions.
*
* @param image
* The image from which to get the boot image.
* @param boot
* If not NULL, it will be filled with a pointer to the boot image, if
* any. That object is owned by the IsoImage and should not be freed by
* the user, nor dereferenced once the last reference to the IsoImage was
* disposed via iso_image_unref().
* @param imgnode
* When not NULL, it will be filled with the image tree node. No extra ref
* is added, you can use iso_node_ref() to get one if you need it.
* @param catnode
* When not NULL, it will be filled with the catnode tree node. No extra
* ref is added, you can use iso_node_ref() to get one if you need it.
* @return
* 1 on success, 0 is the image is not bootable (i.e., it has no El-Torito
* image), < 0 error.
*/
int iso_image_get_boot_image(IsoImage *image, ElToritoBootImage **boot,
IsoFile **imgnode, IsoBoot **catnode)
{
if (image == NULL) {
return ISO_NULL_POINTER;
}
if (image->bootcat == NULL) {
return 0;
}
/* ok, image is bootable */
if (boot) {
*boot = image->bootcat->image;
}
if (imgnode) {
*imgnode = image->bootcat->image->image;
}
if (catnode) {
*catnode = image->bootcat->node;
}
return ISO_SUCCESS;
}
/**
* Removes the El-Torito bootable image.
*
* The IsoBoot node that acts as placeholder for the catalog is also removed
* for the image tree, if there.
* If the image is not bootable (don't have el-torito boot image) this function
* just returns.
*/
void iso_image_remove_boot_image(IsoImage *image)
{
if (image == NULL || image->bootcat == NULL)
return;
/*
* remove catalog node from its parent
* (the reference will be disposed next)
*/
iso_node_take((IsoNode*)image->bootcat->node);
/* free boot catalog and image, including references to nodes */
el_torito_boot_catalog_free(image->bootcat);
image->bootcat = NULL;
}
void el_torito_boot_catalog_free(struct el_torito_boot_catalog *cat)
{
struct el_torito_boot_image *image;
if (cat == NULL) {
return;
}
image = cat->image;
iso_node_unref((IsoNode*)image->image);
free(image);
iso_node_unref((IsoNode*)cat->node);
free(cat);
}
/**
* Stream that generates the contents of a El-Torito catalog.
*/
struct catalog_stream
{
struct el_torito_boot_catalog *catalog;
uint8_t buffer[BLOCK_SIZE];
int offset; /* -1 if stream is not openned */
};
static void
write_validation_entry(uint8_t *buf)
{
size_t i;
int checksum;
struct el_torito_validation_entry *ve =
(struct el_torito_validation_entry*)buf;
ve->header_id[0] = 1;
ve->platform_id[0] = 0; /* 0: 80x86, 1: PowerPC, 2: Mac */
ve->key_byte1[0] = 0x55;
ve->key_byte2[0] = 0xAA;
/* calculate the checksum, to ensure sum of all words is 0 */
checksum = 0;
for (i = 0; i < sizeof(struct el_torito_validation_entry); i += 2) {
checksum -= buf[i];
checksum -= (buf[i] << 8);
}
iso_lsb(ve->checksum, checksum, 2);
}

96
src/eltorito.h Normal file
View File

@ -0,0 +1,96 @@
/*
* Copyright (c) 2007 Vreixo Formoso
*
* 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 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;
/**
* Location of a file extent in a ms disc, 0 for newly added file
*/
uint32_t msblock;
};
struct el_torito_boot_catalog {
IsoBoot *node; /* node of the catalog */
struct el_torito_boot_image *image; /* default boot image */
};
struct el_torito_boot_image {
IsoFile *image;
unsigned int bootable:1; /**< If the entry is bootable. */
unsigned int isolinux:1; /**< If the image will be patched */
unsigned char type; /**< The type of image */
unsigned char partition_type; /**< type of partition for HD-emul images */
short load_seg; /**< Load segment for the initial boot image. */
short load_size; /**< Number of sectors to load. */
};
/** 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 number BP(3, 4);
uint8_t character 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);
#endif /* LIBISO_ELTORITO_H */

4
src/error.h
View File

@ -52,5 +52,9 @@
#define ISO_WRONG_ECMA119 -303
#define ISO_UNSUPPORTED_ECMA119 -304
/* el-torito errors */
#define ISO_IMAGE_ALREADY_BOOTABLE -350
#define ISO_BOOT_IMAGE_NOT_VALID -351
#endif /*LIBISO_ERROR_H_*/

2
src/fs_image.c
View File

@ -32,8 +32,6 @@ static int iso_file_source_new_ifs(IsoImageFilesystem *fs,
IsoFileSource *parent, struct ecma119_dir_record *record,
IsoFileSource **src);
#define ISO_IMAGE_FS_ID 2
/** unique identifier for each image */
unsigned int fs_dev_id = 0;

3
src/fs_local.c
View File

@ -24,9 +24,6 @@
#include <libgen.h>
#include <string.h>
#define ISO_LOCAL_FS_ID 1
static
int iso_file_source_new_lfs(const char *path, IsoFileSource **src);

4
src/fsource.c
View File

@ -10,9 +10,9 @@
#include <stdlib.h>
/**
* Values belong 100 are reserved for out own usage
* Values belong 1000 are reserved for libisofs usage
*/
unsigned int iso_fs_global_id = 100;
unsigned int iso_fs_global_id = 1000;
void iso_file_source_ref(IsoFileSource *src)
{

4
src/fsource.h
View File

@ -19,6 +19,10 @@
#include <sys/stat.h>
#define ISO_LOCAL_FS_ID 1
#define ISO_IMAGE_FS_ID 2
#define ISO_ELTORITO_FS_ID 3
typedef struct Iso_File_Source IsoFileSource;
typedef struct Iso_Filesystem IsoFilesystem;

2
src/image.c
View File

@ -11,6 +11,7 @@
#include "error.h"
#include "node.h"
#include "messages.h"
#include "eltorito.h"
#include <stdlib.h>
#include <string.h>
@ -107,6 +108,7 @@ void iso_image_unref(IsoImage *image)
libiso_msgs_destroy(&image->messenger, 0);
iso_node_builder_unref(image->builder);
iso_filesystem_unref(image->fs);
el_torito_boot_catalog_free(image->bootcat);
free(image->volset_id);
free(image->volume_id);
free(image->publisher_id);

3
src/image.h
View File

@ -99,6 +99,9 @@ struct Iso_Image
char *copyright_file_id;
char *abstract_file_id;
char *biblio_file_id;
/* el-torito boot catalog */
struct el_torito_boot_catalog *bootcat;
/* message messenger for the image */
struct libiso_msgs *messenger;

127
src/libisofs.h
View File

@ -23,6 +23,9 @@ typedef struct Iso_Special IsoSpecial;
typedef struct Iso_Dir_Iter IsoDirIter;
typedef struct el_torito_boot_image ElToritoBootImage;
typedef struct Iso_Boot IsoBoot;
/**
* The type of an IsoNode.
*
@ -56,6 +59,15 @@ enum IsoHideNodeFlag {
LIBISO_HIDE_ON_JOLIET = 1 << 1
};
/**
* El-Torito bootable image type.
*/
enum eltorito_boot_media_type {
ELTORITO_FLOPPY_EMUL,
ELTORITO_HARD_DISC_EMUL,
ELTORITO_NO_EMUL
};
/**
* Holds the options for the image generation.
*/
@ -491,6 +503,121 @@ void iso_image_set_biblio_file_id(IsoImage *image, const char *biblio_file_id);
*/
const char *iso_image_get_biblio_file_id(const IsoImage *image);
/**
* Create a bootable image by adding a El-Torito boot image.
*
* This also add a catalog boot node to the image filesystem tree.
*
* @param image
* The image to make bootable. If it was already bootable this function
* returns an error and the image remains unmodified.
* @param image_path
* The path on the image tree of a regular file to use as default boot
* image.
* @param type
* The boot media type. This can be one of 3 types:
* - Floppy emulation: Boot image file must be exactly
* 1200 kB, 1440 kB or 2880 kB.
* - Hard disc emulation: The image must begin with a master
* boot record with a single image.
* - No emulation. You should specify load segment and load size
* of image.
* @param catalog_path
* The path on the image tree where the catalog will be stored. The
* directory component of this path must be a directory existent on the
* image tree, and the filename component must be unique among all
* children of that directory on image. Otherwise a correspodent error
* code will be returned. This function will add an IsoBoot node that acts
* as a placeholder for the real catalog, that will be generated at image
* creation time.
* @param boot
* Location where a pointer to the added boot image will be stored. That
* object is owned by the IsoImage and should not be freed by the user,
* nor dereferenced once the last reference to the IsoImage was disposed
* via iso_image_unref(). A NULL value is allowed if you don't need a
* reference to the boot image.
* @return
* 1 on success, < 0 on error
*/
int iso_image_set_boot_image(IsoImage *image, const char *image_path,
enum eltorito_boot_media_type type,
const char *catalog_path,
ElToritoBootImage **boot);
//TODO add support for "hidden" bootable images.
/**
* Get El-Torito boot image of an ISO image, if any.
*
* This can be useful, for example, to check if a volume read from a previous
* session or an existing image is bootable. It can also be useful to get
* the image and catalog tree nodes. An application would want those, for
* example, to prevent the user removing it.
*
* Both nodes are owned by libisofs and should not be freed. You can get your
* own ref with iso_node_ref(). You can can also check if the node is already
* on the tree by getting its parent (note that when reading El-Torito info
* from a previous image, the nodes might not be on the tree even if you haven't
* removed them). Remember that you'll need to get a new ref
* (with iso_node_ref()) before inserting them again to the tree, and probably
* you will also need to set the name or permissions.
*
* @param image
* The image from which to get the boot image.
* @param boot
* If not NULL, it will be filled with a pointer to the boot image, if
* any. That object is owned by the IsoImage and should not be freed by
* the user, nor dereferenced once the last reference to the IsoImage was
* disposed via iso_image_unref().
* @param imgnode
* When not NULL, it will be filled with the image tree node. No extra ref
* is added, you can use iso_node_ref() to get one if you need it.
* @param catnode
* When not NULL, it will be filled with the catnode tree node. No extra
* ref is added, you can use iso_node_ref() to get one if you need it.
* @return
* 1 on success, 0 is the image is not bootable (i.e., it has no El-Torito
* image), < 0 error.
*/
int iso_image_get_boot_image(IsoImage *image, ElToritoBootImage **boot,
IsoFile **imgnode, IsoBoot **catnode);
/**
* Removes the El-Torito bootable image.
*
* The IsoBoot node that acts as placeholder for the catalog is also removed
* for the image tree, if there.
* If the image is not bootable (don't have el-torito boot image) this function
* just returns.
*/
void iso_image_remove_boot_image(IsoImage *image);
/**
* Sets the load segment for the initial boot image. This is only for
* no emulation boot images, and is a NOP for other image types.
*/
void el_torito_set_load_seg(ElToritoBootImage *bootimg, short segment);
/**
* Sets the number of sectors (512b) to be load at load segment during
* the initial boot procedure. This is only for
* no emulation boot images, and is a NOP for other image types.
*/
void el_torito_set_load_size(ElToritoBootImage *bootimg, short sectors);
/**
* Marks the specified boot image as not bootable
*/
void el_torito_set_no_bootable(ElToritoBootImage *bootimg);
/**
* Specifies that this image needs to be patched. This involves the writting
* of a 56 bytes boot information table at offset 8 of the boot image file.
* The original boot image file won't be modified.
* This is needed for isolinux boot images.
*/
void el_torito_patch_isolinux_image(ElToritoBootImage *bootimg);
/**
* Increments the reference counting of the given node.
*/