Vreixo Formoso
15 years ago
11 changed files with 750 additions and 7 deletions
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/*
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* Copyright (c) 2007 Vreixo Formoso |
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*
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* This file is part of the libisofs project; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation. See COPYING file for details. |
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*/ |
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#include "eltorito.h" |
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#include "stream.h" |
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#include "error.h" |
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#include "fsource.h" |
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#include "image.h" |
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#include "messages.h" |
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#include <stdlib.h> |
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#include <string.h> |
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/**
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* This table should be written with accuracy values at offset |
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* 8 of boot image, when used ISOLINUX boot loader |
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*/ |
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struct boot_info_table { |
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uint8_t bi_pvd BP(1, 4); /* LBA of primary volume descriptor */ |
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uint8_t bi_file BP(5, 8); /* LBA of boot file */ |
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uint8_t bi_length BP(9, 12); /* Length of boot file */ |
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uint8_t bi_csum BP(13, 16); /* Checksum of boot file */ |
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uint8_t bi_reserved BP(17, 56); /* Reserved */
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}; |
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/**
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* Structure for each one of the four entries in a partition table on a |
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* hard disk image. |
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*/ |
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struct partition_desc { |
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uint8_t boot_ind; |
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uint8_t begin_chs[3]; |
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uint8_t type; |
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uint8_t end_chs[3]; |
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uint8_t start[4]; |
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uint8_t size[4]; |
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}; |
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/**
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* Structures for a Master Boot Record of a hard disk image. |
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*/ |
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struct hard_disc_mbr { |
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uint8_t code_area[440]; |
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uint8_t opt_disk_sg[4]; |
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uint8_t pad[2]; |
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struct partition_desc partition[4]; |
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uint8_t sign1; |
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uint8_t sign2; |
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}; |
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/**
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* Sets the load segment for the initial boot image. This is only for |
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* no emulation boot images, and is a NOP for other image types. |
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*/ |
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void el_torito_set_load_seg(ElToritoBootImage *bootimg, short segment) |
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{ |
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if (bootimg->type != ELTORITO_NO_EMUL) |
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return; |
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bootimg->load_seg = segment; |
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} |
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/**
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* Sets the number of sectors (512b) to be load at load segment during |
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* the initial boot procedure. This is only for no emulation boot images,
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* and is a NOP for other image types. |
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*/ |
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void el_torito_set_load_size(ElToritoBootImage *bootimg, short sectors) |
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{ |
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if (bootimg->type != ELTORITO_NO_EMUL) |
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return; |
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bootimg->load_size = sectors; |
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} |
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/**
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* Marks the specified boot image as not bootable |
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*/ |
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void el_torito_set_no_bootable(ElToritoBootImage *bootimg) |
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{ |
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bootimg->bootable = 0; |
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} |
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/**
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* Specifies that this image needs to be patched. This involves the writting |
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* of a 56 bytes boot information table at offset 8 of the boot image file. |
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* The original boot image file won't be modified. |
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* This is needed for isolinux boot images. |
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*/ |
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void el_torito_patch_isolinux_image(ElToritoBootImage *bootimg) |
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{ |
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bootimg->isolinux = 1; |
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} |
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static |
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int iso_tree_add_boot_node(IsoDir *parent, const char *name, IsoBoot **boot) |
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{ |
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IsoBoot *node; |
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IsoNode **pos; |
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time_t now; |
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if (parent == NULL || name == NULL || boot == NULL) { |
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return ISO_NULL_POINTER; |
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} |
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if (boot) { |
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*boot = NULL; |
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} |
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/* check if the name is valid */ |
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if (!iso_node_is_valid_name(name)) { |
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return ISO_WRONG_ARG_VALUE; |
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} |
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/* find place where to insert */ |
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pos = &(parent->children); |
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while (*pos != NULL && strcmp((*pos)->name, name) < 0) { |
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pos = &((*pos)->next); |
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} |
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if (*pos != NULL && !strcmp((*pos)->name, name)) { |
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/* a node with same name already exists */ |
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return ISO_NODE_NAME_NOT_UNIQUE; |
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} |
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node = calloc(1, sizeof(IsoBoot)); |
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if (node == NULL) { |
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return ISO_MEM_ERROR; |
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} |
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node->node.refcount = 1; |
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node->node.type = LIBISO_BOOT; |
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node->node.name = strdup(name); |
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if (node->node.name == NULL) { |
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free(node); |
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return ISO_MEM_ERROR; |
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} |
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/* atributes from parent */ |
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node->node.mode = S_IFREG | (parent->node.mode & 0444); |
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node->node.uid = parent->node.uid; |
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node->node.gid = parent->node.gid; |
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node->node.hidden = parent->node.hidden; |
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/* current time */ |
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now = time(NULL); |
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node->node.atime = now; |
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node->node.ctime = now; |
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node->node.mtime = now; |
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node->msblock = 0; |
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/* add to dir */ |
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node->node.parent = parent; |
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node->node.next = *pos; |
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*pos = (IsoNode*)node; |
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if (boot) { |
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*boot = node; |
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} |
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return ++parent->nchildren; |
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} |
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static
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int create_image(IsoImage *image, const char *image_path, |
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enum eltorito_boot_media_type type, |
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struct el_torito_boot_image **bootimg) |
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{ |
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int ret; |
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struct el_torito_boot_image *boot; |
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int boot_media_type = 0; |
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int load_sectors = 0; /* number of sector to load */ |
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unsigned char partition_type = 0; |
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IsoNode *imgfile; |
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IsoStream *stream; |
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ret = iso_tree_path_to_node(image, image_path, &imgfile); |
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if (ret < 0) { |
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return ret; |
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} |
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if (ret == 0) { |
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return ISO_FILE_DOESNT_EXIST; |
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} |
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if (imgfile->type != LIBISO_FILE) { |
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return ISO_BOOT_IMAGE_NOT_VALID; |
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} |
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stream = ((IsoFile*)imgfile)->stream; |
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/* we need to read the image at least two times */ |
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if (!iso_stream_is_repeatable(stream)) { |
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return ISO_BOOT_IMAGE_NOT_VALID; |
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} |
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switch (type) { |
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case ELTORITO_FLOPPY_EMUL: |
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switch (iso_stream_get_size(stream)) { |
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case 1200 * 1024: |
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boot_media_type = 1; /* 1.2 meg diskette */ |
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break; |
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case 1440 * 1024: |
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boot_media_type = 2; /* 1.44 meg diskette */ |
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break; |
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case 2880 * 1024: |
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boot_media_type = 3; /* 2.88 meg diskette */ |
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break; |
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default: |
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iso_msg_sorry(image->messenger, LIBISO_EL_TORITO_WRONG_IMG,
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"Invalid image size %d Kb. Must be one of 1.2, 1.44" |
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"or 2.88 Mb", iso_stream_get_size(stream) / 1024); |
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return ISO_BOOT_IMAGE_NOT_VALID; |
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break;
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} |
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/* it seems that for floppy emulation we need to load
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* a single sector (512b) */ |
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load_sectors = 1; |
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break; |
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case ELTORITO_HARD_DISC_EMUL: |
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{ |
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size_t i; |
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struct hard_disc_mbr mbr; |
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int used_partition; |
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/* read the MBR on disc and get the type of the partition */ |
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ret = iso_stream_open(stream); |
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if (ret < 0) { |
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iso_msg_sorry(image->messenger, LIBISO_EL_TORITO_WRONG_IMG,
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"Can't open image file."); |
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return ret; |
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} |
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ret = iso_stream_read(stream, &mbr, sizeof(mbr)); |
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iso_stream_close(stream); |
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if (ret != sizeof(mbr)) { |
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iso_msg_sorry(image->messenger, LIBISO_EL_TORITO_WRONG_IMG,
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"Can't read MBR from image file."); |
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return ret < 0 ? ret : ISO_FILE_READ_ERROR; |
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} |
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/* check valid MBR signature */ |
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if ( mbr.sign1 != 0x55 || mbr.sign2 != 0xAA ) { |
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iso_msg_sorry(image->messenger, LIBISO_EL_TORITO_WRONG_IMG,
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"Invalid MBR. Wrong signature."); |
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return ISO_BOOT_IMAGE_NOT_VALID; |
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} |
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/* ensure single partition */ |
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used_partition = -1; |
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for (i = 0; i < 4; ++i) { |
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if (mbr.partition[i].type != 0) { |
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/* it's an used partition */ |
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if (used_partition != -1) { |
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iso_msg_sorry(image->messenger, LIBISO_EL_TORITO_WRONG_IMG,
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"Invalid MBR. At least 2 partitions: %d and "
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"%d, are being used\n", used_partition, i); |
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return ISO_BOOT_IMAGE_NOT_VALID; |
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} else |
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used_partition = i; |
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} |
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} |
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partition_type = mbr.partition[used_partition].type; |
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} |
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boot_media_type = 4; |
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/* only load the MBR */ |
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load_sectors = 1; |
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break; |
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case ELTORITO_NO_EMUL: |
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boot_media_type = 0; |
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break;
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} |
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boot = calloc(1, sizeof(struct el_torito_boot_image)); |
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if (boot == NULL) { |
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return ISO_MEM_ERROR; |
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} |
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boot->image = (IsoFile*)imgfile; |
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iso_node_ref(imgfile); /* get our ref */ |
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boot->bootable = 1; |
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boot->type = boot_media_type; |
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boot->load_size = load_sectors; |
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boot->partition_type = partition_type; |
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if (bootimg) { |
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*bootimg = boot; |
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} |
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return ISO_SUCCESS; |
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} |
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int iso_image_set_boot_image(IsoImage *image, const char *image_path, |
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enum eltorito_boot_media_type type, |
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const char *catalog_path, |
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ElToritoBootImage **boot) |
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{ |
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int ret; |
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struct el_torito_boot_catalog *catalog; |
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ElToritoBootImage *boot_image= NULL; |
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IsoBoot *cat_node= NULL; |
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if (image == NULL || image_path == NULL || catalog_path == NULL) { |
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return ISO_NULL_POINTER; |
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} |
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if (image->bootcat != NULL) { |
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return ISO_IMAGE_ALREADY_BOOTABLE; |
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} |
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/* create the node for the catalog */ |
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{ |
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IsoDir *parent; |
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char *catdir = NULL, *catname = NULL; |
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catdir = strdup(catalog_path); |
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if (catdir == NULL) { |
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return ISO_MEM_ERROR; |
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} |
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/* get both the dir and the name */
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catname = strrchr(catdir, '/'); |
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if (catname == NULL) { |
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free(catdir); |
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return ISO_WRONG_ARG_VALUE; |
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} |
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if (catname == catdir) { |
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/* we are apending catalog to root node */ |
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parent = image->root; |
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} else { |
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IsoNode *p; |
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catname[0] = '\0'; |
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ret = iso_tree_path_to_node(image, catdir, &p); |
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if (ret <= 0) { |
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free(catdir); |
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return ret < 0 ? ret : ISO_FILE_DOESNT_EXIST; |
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} |
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if (p->type != LIBISO_DIR) { |
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free(catdir); |
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return ISO_WRONG_ARG_VALUE; |
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} |
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parent = (IsoDir*)p; |
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} |
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catname++; |
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ret = iso_tree_add_boot_node(parent, catname, &cat_node); |
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free(catdir); |
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if (ret < 0) { |
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return ret; |
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} |
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} |
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/* create the boot image */ |
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ret = create_image(image, image_path, type, &boot_image); |
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if (ret < 0) { |
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goto boot_image_cleanup; |
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} |
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/* creates the catalog with the given image */ |
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catalog = malloc(sizeof(struct el_torito_boot_catalog)); |
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if (catalog == NULL) { |
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ret = ISO_MEM_ERROR; |
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goto boot_image_cleanup; |
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} |
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catalog->image = boot_image; |
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catalog->node = cat_node; |
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iso_node_ref((IsoNode*)cat_node); |
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image->bootcat = catalog; |
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if (boot) { |
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*boot = boot_image; |
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} |
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return ISO_SUCCESS; |
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boot_image_cleanup:; |
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if (cat_node) { |
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iso_node_take((IsoNode*)cat_node); |
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iso_node_unref((IsoNode*)cat_node); |
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} |
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if (boot_image) { |
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iso_node_unref((IsoNode*)boot_image->image); |
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free(boot_image); |
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} |
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return ret; |
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} |
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/**
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* Get El-Torito boot image of an ISO image, if any. |
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*
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* This can be useful, for example, to check if a volume read from a previous |
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* session or an existing image is bootable. It can also be useful to get |
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* the image and catalog tree nodes. An application would want those, for
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* example, to prevent the user removing it. |
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*
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* Both nodes are owned by libisofs and should not be freed. You can get your |
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* own ref with iso_node_ref(). You can can also check if the node is already
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* on the tree by getting its parent (note that when reading El-Torito info
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* from a previous image, the nodes might not be on the tree even if you haven't
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* removed them). Remember that you'll need to get a new ref
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* (with iso_node_ref()) before inserting them again to the tree, and probably
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* you will also need to set the name or permissions. |
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*
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* @param image |
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* The image from which to get the boot image. |
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* @param boot |
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* If not NULL, it will be filled with a pointer to the boot image, if
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* any. That object is owned by the IsoImage and should not be freed by
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* the user, nor dereferenced once the last reference to the IsoImage was |
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* disposed via iso_image_unref(). |
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* @param imgnode
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* When not NULL, it will be filled with the image tree node. No extra ref |
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* is added, you can use iso_node_ref() to get one if you need it. |
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* @param catnode
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* When not NULL, it will be filled with the catnode tree node. No extra
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* ref is added, you can use iso_node_ref() to get one if you need it. |
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* @return |
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* 1 on success, 0 is the image is not bootable (i.e., it has no El-Torito |
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* image), < 0 error. |
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*/ |
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int iso_image_get_boot_image(IsoImage *image, ElToritoBootImage **boot, |
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IsoFile **imgnode, IsoBoot **catnode) |
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{ |
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if (image == NULL) { |
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return ISO_NULL_POINTER; |
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} |
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if (image->bootcat == NULL) { |
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return 0; |
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} |
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/* ok, image is bootable */ |
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if (boot) { |
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*boot = image->bootcat->image; |
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} |
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if (imgnode) { |
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*imgnode = image->bootcat->image->image; |
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} |
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if (catnode) { |
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*catnode = image->bootcat->node; |
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} |
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return ISO_SUCCESS; |
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} |
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/**
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* Removes the El-Torito bootable image.
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*
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* The IsoBoot node that acts as placeholder for the catalog is also removed |
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* for the image tree, if there. |
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* If the image is not bootable (don't have el-torito boot image) this function |
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* just returns. |
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*/ |
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void iso_image_remove_boot_image(IsoImage *image) |
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{ |
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if (image == NULL || image->bootcat == NULL) |
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return; |
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/*
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* remove catalog node from its parent
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* (the reference will be disposed next)
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*/ |
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iso_node_take((IsoNode*)image->bootcat->node); |
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/* free boot catalog and image, including references to nodes */ |
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el_torito_boot_catalog_free(image->bootcat); |
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image->bootcat = NULL; |
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} |
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void el_torito_boot_catalog_free(struct el_torito_boot_catalog *cat) |
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{ |
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struct el_torito_boot_image *image; |
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if (cat == NULL) { |
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return; |
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} |
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image = cat->image; |
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iso_node_unref((IsoNode*)image->image); |
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free(image); |
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iso_node_unref((IsoNode*)cat->node); |
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free(cat); |
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} |
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/**
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* Stream that generates the contents of a El-Torito catalog. |
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*/ |
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struct catalog_stream |
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{ |
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struct el_torito_boot_catalog *catalog; |
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uint8_t buffer[BLOCK_SIZE]; |
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int offset; /* -1 if stream is not openned */ |
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}; |
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static void
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write_validation_entry(uint8_t *buf) |
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{ |
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size_t i; |
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int checksum; |
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struct el_torito_validation_entry *ve =
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(struct el_torito_validation_entry*)buf; |
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ve->header_id[0] = 1; |
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ve->platform_id[0] = 0; /* 0: 80x86, 1: PowerPC, 2: Mac */ |
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ve->key_byte1[0] = 0x55; |
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ve->key_byte2[0] = 0xAA; |
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/* calculate the checksum, to ensure sum of all words is 0 */ |
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checksum = 0; |
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for (i = 0; i < sizeof(struct el_torito_validation_entry); i += 2) { |
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checksum -= buf[i]; |
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checksum -= (buf[i] << 8); |
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} |
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iso_lsb(ve->checksum, checksum, 2); |
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} |
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@ -0,0 +1,96 @@
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/*
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* Copyright (c) 2007 Vreixo Formoso |
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*
|
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* This file is part of the libisofs project; you can redistribute it and/or
|
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* modify it under the terms of the GNU General Public License version 2 as
|
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* published by the Free Software Foundation. See COPYING file for details. |
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*/ |
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|
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/**
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* Declare El-Torito related structures. |
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* References: |
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* "El Torito" Bootable CD-ROM Format Specification Version 1.0 (1995) |
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*/ |
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#ifndef LIBISO_ELTORITO_H |
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#define LIBISO_ELTORITO_H |
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|
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#include "ecma119.h" |
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#include "node.h" |
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/**
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* A node that acts as a placeholder for an El-Torito catalog. |
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*/ |
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struct Iso_Boot |
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{ |
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IsoNode node; |
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|
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/**
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* Location of a file extent in a ms disc, 0 for newly added file |
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*/ |
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uint32_t msblock; |
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}; |
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|
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struct el_torito_boot_catalog { |
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IsoBoot *node; /* node of the catalog */ |
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struct el_torito_boot_image *image; /* default boot image */ |
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}; |
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|
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struct el_torito_boot_image { |
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IsoFile *image; |
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|
||||
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 */ |
||||
Loading…
Reference in new issue