/*      $NetBSD: cd9660_eltorito.c,v 1.27 2023/12/28 12:13:56 tsutsui Exp $     */

/*
* Copyright (c) 2005 Daniel Watt, Walter Deignan, Ryan Gabrys, Alan
* Perez-Rathke and Ram Vedam.  All rights reserved.
*
* This code was written by Daniel Watt, Walter Deignan, Ryan Gabrys,
* Alan Perez-Rathke and Ram Vedam.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY DANIEL WATT, WALTER DEIGNAN, RYAN
* GABRYS, ALAN PEREZ-RATHKE AND RAM VEDAM ``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 DANIEL WATT, WALTER DEIGNAN, RYAN
* GABRYS, ALAN PEREZ-RATHKE AND RAM VEDAM 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.
*/


#include "cd9660.h"
#include "cd9660_eltorito.h"
#include <sys/bootblock.h>
#include <util.h>

#include <sys/cdefs.h>
#if defined(__RCSID) && !defined(__lint)
__RCSID("$NetBSD: cd9660_eltorito.c,v 1.27 2023/12/28 12:13:56 tsutsui Exp $");
#endif  /* !__lint */

#ifdef DEBUG
#define ELTORITO_DPRINTF(__x)   printf __x
#else
#define ELTORITO_DPRINTF(__x)
#endif

#include <util.h>

static struct boot_catalog_entry *cd9660_init_boot_catalog_entry(void);
static struct boot_catalog_entry *cd9660_boot_setup_validation_entry(char);
static struct boot_catalog_entry *cd9660_boot_setup_default_entry(
   struct cd9660_boot_image *);
static struct boot_catalog_entry *cd9660_boot_setup_section_head(char);
#if 0
static u_char cd9660_boot_get_system_type(struct cd9660_boot_image *);
#endif

static struct cd9660_boot_image *default_boot_image;

int
cd9660_add_boot_disk(iso9660_disk *diskStructure, const char *boot_info)
{
       struct stat stbuf;
       const char *mode_msg;
       char *temp;
       char *sysname;
       char *filename;
       struct cd9660_boot_image *new_image, *tmp_image;

       assert(boot_info != NULL);

       if (*boot_info == '\0') {
               warnx("Error: Boot disk information must be in the "
                     "format 'system;filename'");
               return 0;
       }

       /* First decode the boot information */
       temp = estrdup(boot_info);

       sysname = temp;
       filename = strchr(sysname, ';');
       if (filename == NULL) {
               warnx("supply boot disk information in the format "
                   "'system;filename'");
               free(temp);
               return 0;
       }

       *filename++ = '\0';

       if (diskStructure->verbose_level > 0) {
               printf("Found bootdisk with system %s, and filename %s\n",
                   sysname, filename);
       }
       new_image = ecalloc(1, sizeof(*new_image));
       new_image->loadSegment = 0;     /* default for now */

       /* Decode System */
       if (strcmp(sysname, "i386") == 0)
               new_image->system = ET_SYS_X86;
       else if (strcmp(sysname, "powerpc") == 0)
               new_image->system = ET_SYS_PPC;
       else if (strcmp(sysname, "macppc") == 0 ||
                strcmp(sysname, "mac68k") == 0)
               new_image->system = ET_SYS_MAC;
       else if (strcmp(sysname, "efi") == 0)
               new_image->system = ET_SYS_EFI;
       else {
               warnx("boot disk system must be "
                     "i386, powerpc, macppc, mac68k, or efi");
               free(temp);
               free(new_image);
               return 0;
       }


       new_image->filename = estrdup(filename);

       free(temp);

       /* Get information about the file */
       if (lstat(new_image->filename, &stbuf) == -1)
               err(EXIT_FAILURE, "%s: lstat(\"%s\")", __func__,
                   new_image->filename);

       switch (stbuf.st_size) {
       case 1440 * 1024:
               new_image->targetMode = ET_MEDIA_144FDD;
               mode_msg = "Assigned boot image to 1.44 emulation mode";
               break;
       case 1200 * 1024:
               new_image->targetMode = ET_MEDIA_12FDD;
               mode_msg = "Assigned boot image to 1.2 emulation mode";
               break;
       case 2880 * 1024:
               new_image->targetMode = ET_MEDIA_288FDD;
               mode_msg = "Assigned boot image to 2.88 emulation mode";
               break;
       default:
               new_image->targetMode = ET_MEDIA_NOEM;
               mode_msg = "Assigned boot image to no emulation mode";
               break;
       }

       if (diskStructure->verbose_level > 0)
               printf("%s\n", mode_msg);

       new_image->size = stbuf.st_size;
       new_image->num_sectors =
           howmany(new_image->size, diskStructure->sectorSize) *
           howmany(diskStructure->sectorSize, 512);
       if (diskStructure->verbose_level > 0) {
               printf("New image has size %d, uses %d 512-byte sectors\n",
                   new_image->size, new_image->num_sectors);
       }
       new_image->sector = -1;
       /* Bootable by default */
       new_image->bootable = ET_BOOTABLE;
       /* Add boot disk */

       /* Group images for the same platform together. */
       TAILQ_FOREACH(tmp_image, &diskStructure->boot_images, image_list) {
               if (tmp_image->system != new_image->system)
                       break;
       }

       if (tmp_image == NULL) {
               TAILQ_INSERT_HEAD(&diskStructure->boot_images, new_image,
                   image_list);
       } else
               TAILQ_INSERT_BEFORE(tmp_image, new_image, image_list);

       new_image->serialno = diskStructure->image_serialno++;

       new_image->platform_id = new_image->system;

       /* TODO : Need to do anything about the boot image in the tree? */
       diskStructure->is_bootable = 1;

       /* First boot image is initial/default entry. */
       if (default_boot_image == NULL)
               default_boot_image = new_image;

       return 1;
}

int
cd9660_eltorito_add_boot_option(iso9660_disk *diskStructure,
   const char *option_string, const char *value)
{
       char *eptr;
       struct cd9660_boot_image *image;

       assert(option_string != NULL);

       /* Find the last image added */
       TAILQ_FOREACH(image, &diskStructure->boot_images, image_list) {
               if (image->serialno + 1 == diskStructure->image_serialno)
                       break;
       }
       if (image == NULL)
               errx(EXIT_FAILURE, "Attempted to add boot option, "
                   "but no boot images have been specified");

       if (strcmp(option_string, "no-emul-boot") == 0) {
               image->targetMode = ET_MEDIA_NOEM;
       } else if (strcmp(option_string, "no-boot") == 0) {
               image->bootable = ET_NOT_BOOTABLE;
       } else if (strcmp(option_string, "hard-disk-boot") == 0) {
               image->targetMode = ET_MEDIA_HDD;
       } else if (strcmp(option_string, "boot-load-segment") == 0) {
               image->loadSegment = strtoul(value, &eptr, 16);
               if (eptr == value || *eptr != '\0' || errno != ERANGE) {
                       warn("%s: strtoul", __func__);
                       return 0;
               }
       } else if (strcmp(option_string, "platformid") == 0) {
               if (strcmp(value, "efi") == 0)
                       image->platform_id = ET_SYS_EFI;
               else {
                       warn("%s: unknown platform: %s", __func__, value);
                       return 0;
               }
       } else {
               return 0;
       }
       return 1;
}

static struct boot_catalog_entry *
cd9660_init_boot_catalog_entry(void)
{
       return ecalloc(1, sizeof(struct boot_catalog_entry));
}

static struct boot_catalog_entry *
cd9660_boot_setup_validation_entry(char sys)
{
       struct boot_catalog_entry *entry;
       boot_catalog_validation_entry *ve;
       int16_t checksum;
       unsigned char *csptr;
       size_t i;
       entry = cd9660_init_boot_catalog_entry();

       entry->entry_type = ET_ENTRY_VE;
       ve = &entry->entry_data.VE;

       ve->header_id[0] = 1;
       ve->platform_id[0] = sys;
       ve->key[0] = 0x55;
       ve->key[1] = 0xAA;

       /* Calculate checksum */
       checksum = 0;
       cd9660_721(0, ve->checksum);
       csptr = (unsigned char*)ve;
       for (i = 0; i < sizeof(*ve); i += 2) {
               checksum += (int16_t)csptr[i];
               checksum += 256 * (int16_t)csptr[i + 1];
       }
       checksum = -checksum;
       cd9660_721(checksum, ve->checksum);

       ELTORITO_DPRINTF(("%s: header_id %d, platform_id %d, key[0] %d, key[1] %d, "
           "checksum %04x\n", __func__, ve->header_id[0], ve->platform_id[0],
           ve->key[0], ve->key[1], checksum));
       return entry;
}

static struct boot_catalog_entry *
cd9660_boot_setup_default_entry(struct cd9660_boot_image *disk)
{
       struct boot_catalog_entry *default_entry;
       boot_catalog_initial_entry *ie;

       default_entry = cd9660_init_boot_catalog_entry();
       if (default_entry == NULL)
               return NULL;

       default_entry->entry_type = ET_ENTRY_IE;
       ie = &default_entry->entry_data.IE;

       ie->boot_indicator[0] = disk->bootable;
       ie->media_type[0] = disk->targetMode;
       cd9660_721(disk->loadSegment, ie->load_segment);
       ie->system_type[0] = disk->system;
       cd9660_721(disk->num_sectors, ie->sector_count);
       cd9660_731(disk->sector, ie->load_rba);

       ELTORITO_DPRINTF(("%s: boot indicator %d, media type %d, "
           "load segment %04x, system type %d, sector count %d, "
           "load rba %d\n", __func__, ie->boot_indicator[0],
           ie->media_type[0], disk->loadSegment, ie->system_type[0],
           disk->num_sectors, disk->sector));
       return default_entry;
}

static struct boot_catalog_entry *
cd9660_boot_setup_section_head(char platform)
{
       struct boot_catalog_entry *entry;
       boot_catalog_section_header *sh;

       entry = cd9660_init_boot_catalog_entry();
       if (entry == NULL)
               return NULL;

       entry->entry_type = ET_ENTRY_SH;
       sh = &entry->entry_data.SH;
       /* More by default. The last one will manually be set to 0x91 */
       sh->header_indicator[0] = ET_SECTION_HEADER_MORE;
       sh->platform_id[0] = platform;
       sh->num_section_entries[0] = 0;
       return entry;
}

static struct boot_catalog_entry *
cd9660_boot_setup_section_entry(struct cd9660_boot_image *disk)
{
       struct boot_catalog_entry *entry;
       boot_catalog_section_entry *se;
       if ((entry = cd9660_init_boot_catalog_entry()) == NULL)
               return NULL;

       entry->entry_type = ET_ENTRY_SE;
       se = &entry->entry_data.SE;

       se->boot_indicator[0] = ET_BOOTABLE;
       se->media_type[0] = disk->targetMode;
       cd9660_721(disk->loadSegment, se->load_segment);
       cd9660_721(disk->num_sectors, se->sector_count);
       cd9660_731(disk->sector, se->load_rba);
       return entry;
}

#if 0
static u_char
cd9660_boot_get_system_type(struct cd9660_boot_image *disk)
{
       /*
               For hard drive booting, we need to examine the MBR to figure
               out what the partition type is
       */
       return 0;
}
#endif

/*
* Set up the BVD, Boot catalog, and the boot entries, but do no writing
*/
int
cd9660_setup_boot(iso9660_disk *diskStructure, int first_sector)
{
       int sector;
       int used_sectors;
       int num_entries = 0;
       int catalog_sectors;
       struct boot_catalog_entry *x86_head, *mac_head, *ppc_head, *efi_head,
               *valid_entry, *default_entry, *temp, *head, **headp, *next;
       struct cd9660_boot_image *tmp_disk;
       u_char system;

       headp = NULL;
       x86_head = mac_head = ppc_head = efi_head = NULL;

       /* If there are no boot disks, don't bother building boot information */
       if (TAILQ_EMPTY(&diskStructure->boot_images))
               return 0;

       /* Point to catalog: For now assume it consumes one sector */
       ELTORITO_DPRINTF(("Boot catalog will go in sector %d\n", first_sector));
       diskStructure->boot_catalog_sector = first_sector;
       cd9660_731(first_sector,
           diskStructure->boot_descriptor->boot_catalog_pointer);

       /*
        * Use system type of default image for validation entry. Fallback to
        * X86 system type if not found.
        */
       system = default_boot_image != NULL ? default_boot_image->system :
                                             ET_SYS_X86;

       /* Step 1: Generate boot catalog */
       /* Step 1a: Validation entry */
       valid_entry = cd9660_boot_setup_validation_entry(system);
       if (valid_entry == NULL)
               return -1;

       /*
        * Count how many boot images there are,
        * and how many sectors they consume.
        */
       num_entries = 1;
       used_sectors = 0;

       TAILQ_FOREACH(tmp_disk, &diskStructure->boot_images, image_list) {
               used_sectors += tmp_disk->num_sectors;

               /* One default entry per image */
               num_entries++;
       }
       catalog_sectors = howmany(num_entries * 0x20, diskStructure->sectorSize);
       used_sectors += catalog_sectors;

       if (diskStructure->verbose_level > 0) {
               printf("%s: there will be %i entries consuming %i sectors. "
                      "Catalog is %i sectors\n", __func__, num_entries,
                      used_sectors, catalog_sectors);
       }

       /* Populate sector numbers */
       sector = first_sector + catalog_sectors;
       TAILQ_FOREACH(tmp_disk, &diskStructure->boot_images, image_list) {
               tmp_disk->sector = sector;
               sector += tmp_disk->num_sectors /
                   (diskStructure->sectorSize / 512);
       }

       LIST_INSERT_HEAD(&diskStructure->boot_entries, valid_entry, ll_struct);

       /* Step 1b: Initial/default entry */
       /* TODO : PARAM */
       if (default_boot_image != NULL) {
               struct cd9660_boot_image *tcbi;
               TAILQ_FOREACH(tcbi, &diskStructure->boot_images, image_list) {
                       if (tcbi == default_boot_image) {
                               tmp_disk = tcbi;
                               break;
                       }
               }
       }
       if (tmp_disk == NULL)
               tmp_disk = TAILQ_FIRST(&diskStructure->boot_images);
       default_entry = cd9660_boot_setup_default_entry(tmp_disk);
       if (default_entry == NULL) {
               warnx("Error: memory allocation failed in cd9660_setup_boot");
               return -1;
       }

       LIST_INSERT_AFTER(valid_entry, default_entry, ll_struct);

       /* Todo: multiple default entries? */

       tmp_disk = TAILQ_FIRST(&diskStructure->boot_images);

       head = NULL;
       temp = default_entry;

       /* If multiple boot images are given : */
       for (; tmp_disk != NULL; tmp_disk = TAILQ_NEXT(tmp_disk, image_list)) {
               if (tmp_disk == default_boot_image)
                       continue;

               /* Step 2: Section header */
               switch (tmp_disk->platform_id) {
               case ET_SYS_X86:
                       headp = &x86_head;
                       break;
               case ET_SYS_PPC:
                       headp = &ppc_head;
                       break;
               case ET_SYS_MAC:
                       headp = &mac_head;
                       break;
               case ET_SYS_EFI:
                       headp = &efi_head;
                       break;
               default:
                       warnx("%s: internal error: unknown system type",
                           __func__);
                       return -1;
               }

               if (*headp == NULL) {
                       head =
                         cd9660_boot_setup_section_head(tmp_disk->platform_id);
                       if (head == NULL) {
                               warnx("Error: memory allocation failed in "
                                     "cd9660_setup_boot");
                               return -1;
                       }
                       LIST_INSERT_AFTER(default_entry, head, ll_struct);
                       *headp = head;
               } else
                       head = *headp;

               head->entry_data.SH.num_section_entries[0]++;

               /* Step 2a: Section entry and extensions */
               temp = cd9660_boot_setup_section_entry(tmp_disk);
               if (temp == NULL) {
                       warn("%s: cd9660_boot_setup_section_entry", __func__);
                       return -1;
               }

               while ((next = LIST_NEXT(head, ll_struct)) != NULL &&
                      next->entry_type == ET_ENTRY_SE)
                       head = next;

               LIST_INSERT_AFTER(head, temp, ll_struct);
       }

       /* Find the last Section Header entry and mark it as the last. */
       head = NULL;
       LIST_FOREACH(next, &diskStructure->boot_entries, ll_struct) {
               if (next->entry_type == ET_ENTRY_SH)
                       head = next;
       }
       if (head != NULL)
               head->entry_data.SH.header_indicator[0] = ET_SECTION_HEADER_LAST;

       /* TODO: Remaining boot disks when implemented */

       return first_sector + used_sectors;
}

int
cd9660_setup_boot_volume_descriptor(iso9660_disk *diskStructure,
   volume_descriptor *bvd)
{
       boot_volume_descriptor *bvdData =
           (boot_volume_descriptor*)bvd->volumeDescriptorData;

       bvdData->boot_record_indicator[0] = ISO_VOLUME_DESCRIPTOR_BOOT;
       memcpy(bvdData->identifier, ISO_VOLUME_DESCRIPTOR_STANDARD_ID, 5);
       bvdData->version[0] = 1;
       memcpy(bvdData->boot_system_identifier, ET_ID, 23);
       memcpy(bvdData->identifier, ISO_VOLUME_DESCRIPTOR_STANDARD_ID, 5);
       diskStructure->boot_descriptor =
           (boot_volume_descriptor*) bvd->volumeDescriptorData;
       return 1;
}

static int
cd9660_write_mbr_partition_entry(FILE *fd, int idx, off_t sector_start,
   off_t nsectors, int type)
{
       uint8_t val;
       uint32_t lba;

       if (fseeko(fd, (off_t)(idx) * 16 + 0x1be, SEEK_SET) == -1)
               err(EXIT_FAILURE, "fseeko");

       val = 0x80; /* Bootable */
       fwrite(&val, sizeof(val), 1, fd);

       val = 0xff; /* CHS begin */
       fwrite(&val, sizeof(val), 1, fd);
       fwrite(&val, sizeof(val), 1, fd);
       fwrite(&val, sizeof(val), 1, fd);

       val = type; /* Part type */
       fwrite(&val, sizeof(val), 1, fd);

       val = 0xff; /* CHS end */
       fwrite(&val, sizeof(val), 1, fd);
       fwrite(&val, sizeof(val), 1, fd);
       fwrite(&val, sizeof(val), 1, fd);

       /* LBA extent */
       lba = htole32(sector_start);
       fwrite(&lba, sizeof(lba), 1, fd);
       lba = htole32(nsectors);
       fwrite(&lba, sizeof(lba), 1, fd);

       return 0;
}

static int
cd9660_write_apm_partition_entry(FILE *fd, int idx, int total_partitions,
   off_t sector_start, off_t nsectors, off_t sector_size,
   const char *part_name, const char *part_type)
{
       uint32_t apm32, part_status;
       uint16_t apm16;

       /* See Apple Tech Note 1189 for the details about the pmPartStatus
        * flags.
        * Below the flags which are default:
        * - IsValid     0x01
        * - IsAllocated 0x02
        * - IsReadable  0x10
        * - IsWritable  0x20
        */
       part_status = APPLE_PS_VALID | APPLE_PS_ALLOCATED | APPLE_PS_READABLE |
           APPLE_PS_WRITABLE;

       if (fseeko(fd, (off_t)(idx + 1) * sector_size, SEEK_SET) == -1)
               err(EXIT_FAILURE, "fseeko");

       /* Signature */
       apm16 = htobe16(0x504d);
       fwrite(&apm16, sizeof(apm16), 1, fd);
       apm16 = 0;
       fwrite(&apm16, sizeof(apm16), 1, fd);

       /* Total number of partitions */
       apm32 = htobe32(total_partitions);
       fwrite(&apm32, sizeof(apm32), 1, fd);
       /* Bounds */
       apm32 = htobe32(sector_start);
       fwrite(&apm32, sizeof(apm32), 1, fd);
       apm32 = htobe32(nsectors);
       fwrite(&apm32, sizeof(apm32), 1, fd);

       fwrite(part_name, strlen(part_name) + 1, 1, fd);
       fseek(fd, 32 - strlen(part_name) - 1, SEEK_CUR);
       fwrite(part_type, strlen(part_type) + 1, 1, fd);
       fseek(fd, 32 - strlen(part_type) - 1, SEEK_CUR);

       apm32 = 0;
       /* pmLgDataStart */
       fwrite(&apm32, sizeof(apm32), 1, fd);
       /* pmDataCnt */
       apm32 = htobe32(nsectors);
       fwrite(&apm32, sizeof(apm32), 1, fd);
       /* pmPartStatus */
       apm32 = htobe32(part_status);
       fwrite(&apm32, sizeof(apm32), 1, fd);

       return 0;
}

int
cd9660_write_boot(iso9660_disk *diskStructure, FILE *fd)
{
       struct boot_catalog_entry *e;
       struct cd9660_boot_image *t;
       int apm_partitions = 0;
       int mbr_partitions = 0;

       /* write boot catalog */
       if (fseeko(fd, (off_t)diskStructure->boot_catalog_sector *
           diskStructure->sectorSize, SEEK_SET) == -1)
               err(EXIT_FAILURE, "fseeko");

       if (diskStructure->verbose_level > 0) {
               printf("Writing boot catalog to sector %" PRId64 "\n",
                   diskStructure->boot_catalog_sector);
       }
       LIST_FOREACH(e, &diskStructure->boot_entries, ll_struct) {
               if (diskStructure->verbose_level > 0) {
                       printf("Writing catalog entry of type %d\n",
                           e->entry_type);
               }
               /*
                * It doesnt matter which one gets written
                * since they are the same size
                */
               fwrite(&(e->entry_data.VE), 1, 32, fd);
       }
       if (diskStructure->verbose_level > 0)
               printf("Finished writing boot catalog\n");

       /* copy boot images */
       TAILQ_FOREACH(t, &diskStructure->boot_images, image_list) {
               if (diskStructure->verbose_level > 0) {
                       printf("Writing boot image from %s to sectors %d\n",
                           t->filename, t->sector);
               }
               cd9660_copy_file(diskStructure, fd, t->sector, t->filename);

               if (t->system == ET_SYS_MAC)
                       apm_partitions++;
               if (t->system == ET_SYS_PPC)
                       mbr_partitions++;
       }

       /* some systems need partition tables as well */
       if (mbr_partitions > 0 || diskStructure->chrp_boot) {
               uint16_t sig;

               fseek(fd, 0x1fe, SEEK_SET);
               sig = htole16(0xaa55);
               fwrite(&sig, sizeof(sig), 1, fd);

               mbr_partitions = 0;

               /* Write ISO9660 descriptor, enclosing the whole disk */
               if (diskStructure->chrp_boot)
                       cd9660_write_mbr_partition_entry(fd, mbr_partitions++,
                           0, diskStructure->totalSectors *
                           (diskStructure->sectorSize / 512), 0x96);

               /* Write all partition entries */
               TAILQ_FOREACH(t, &diskStructure->boot_images, image_list) {
                       if (t->system != ET_SYS_PPC)
                               continue;
                       cd9660_write_mbr_partition_entry(fd, mbr_partitions++,
                           t->sector * (diskStructure->sectorSize / 512),
                           t->num_sectors * (diskStructure->sectorSize / 512),
                           0x41 /* PReP Boot */);
               }
       }

       if (apm_partitions > 0) {
               /* Write DDR and global APM info */
               uint32_t apm32;
               uint16_t apm16;
               int total_parts;

               fseek(fd, 0, SEEK_SET);
               apm16 = htobe16(0x4552);
               fwrite(&apm16, sizeof(apm16), 1, fd);
               /* Device block size */
               apm16 = htobe16(512);
               fwrite(&apm16, sizeof(apm16), 1, fd);
               /* Device block count */
               apm32 = htobe32(diskStructure->totalSectors *
                   (diskStructure->sectorSize / 512));
               fwrite(&apm32, sizeof(apm32), 1, fd);
               /* Device type/id */
               apm16 = htobe16(1);
               fwrite(&apm16, sizeof(apm16), 1, fd);
               fwrite(&apm16, sizeof(apm16), 1, fd);

               /* Count total needed entries */
               total_parts = 2 + apm_partitions; /* Self + ISO9660 */

               /* Write self-descriptor */
               cd9660_write_apm_partition_entry(fd, 0, total_parts, 1,
                   total_parts, 512, "Apple", "Apple_partition_map");

               /* Write all partition entries */
               apm_partitions = 0;
               TAILQ_FOREACH(t, &diskStructure->boot_images, image_list) {
                       if (t->system != ET_SYS_MAC)
                               continue;

                       cd9660_write_apm_partition_entry(fd,
                           1 + apm_partitions++, total_parts,
                           t->sector * (diskStructure->sectorSize / 512),
                           t->num_sectors * (diskStructure->sectorSize / 512),
                           512, "CD Boot", "Apple_Bootstrap");
               }

               /* Write ISO9660 descriptor, enclosing the whole disk */
               cd9660_write_apm_partition_entry(fd, 2 + apm_partitions,
                   total_parts, 0, diskStructure->totalSectors *
                   (diskStructure->sectorSize / 512), 512, "ISO9660",
                   "CD_ROM_Mode_1");
       }

       return 0;
}