New -boot_image bootspec appended_gpt_with_gaps=

xorriso/xorriso.texi

@@ -50,7 +50,7 @@
 @c man .\" First parameter, NAME, should be all caps
 @c man .\" Second parameter, SECTION, should be 1-8, maybe w/ subsection
 @c man .\" other parameters are allowed: see man(7), man(1)
-@c man .TH XORRISO 1 "Version 1.5.7, Nov 01, 2024"
+@c man .TH XORRISO 1 "Version 1.5.7, Dec 08, 2024"
 @c man .\" Please adjust this date whenever revising the manpage.
 @c man .\"
 @c man .\" Some roff macros, for reference:
@@ -4590,7 +4590,7 @@ Command -volume_date "uuid" can be used to set their value.
 @*
 @strong{bin_path=} depicts an El Torito boot image file, a binary program
 which is to be started by the hardware boot facility (e.g. the BIOS)
-at boot time.
+at boot time. Default platform_id is 0x00 = legacy 80x86 BIOS.
 @*
 @strong{efi_path=} depicts an El Torito boot image file that is ready for
 EFI booting. This is normally a FAT filesystem image not larger than
@@ -4603,9 +4603,12 @@ It controls the boot medium emulation code of a boot image.
 The default "no_emulation" is suitable for ISOLINUX, GRUB, FreeBSD cdboot.
 @*
 @strong{load_size=} is a value which depends on the boot image.
-Default is 2048 which matches the expectations of most boot images.
-The special value "full" means the full size of the boot image file
-rounded up to a multiple of 2048 bytes. Maximum is 33,552,384 bytes.
+Default for legacy BIOS is 2048 which matches the expectations of most BIOS
+boot images. The special value "full" means the full size of the boot image
+file rounded up to a multiple of 2048 bytes. Maximum is 33,552,384 bytes.
+With EFI boot images the default is the full image size. Images which exceed
+the maximum size get size 0 or 1, which means "up to the end of the device"
+according to the UEFI specification.
 @*
 @strong{boot_info_table=on} causes address patching to bytes 8 to 63
 of the boot image which is given by "any" "bin_path=".
@@ -4765,6 +4768,24 @@ influenced by -append_partition parameter partition_number.
 By default, appended partitions get marked in APM only if APM is
 produced because of other options together with part_like_isohybrid="on".
 @*
+The next two settings apply only if partitions get appended by command
+-append_partition and if GPT emerges at all, e.g. by appended_part_as=gpt.
+@*
+@cindex Appended partition, gaps in GPT
+@strong{appended_gpt_with_gaps=on} increases the chance to get in GPT the
+partition numbers given with command -append_partition.
+It may leave some parts of the resulting image unclaimed by partitions in
+the emerging GPT. The ISO 9660 filesystem gets marked by a GPT partition
+only if none of the appended partitions has partition number 1,
+and if no other command causes a partition inside the emerging ISO 9660
+filesystem, and if partition_offset=16.
+@*
+@strong{appended_gpt_with_gaps=off} causes the default behavior of inserting
+gap filling partitions so that no part of the emerging image after block 16
+is unclaimed by GPT partitions. This happens only if partitions get appended
+and a valid GPT emerges, e.g. by appended_part_as=gpt.
+Commands which produce isohybrid-style invalid GPT disable gap filling.
+@*
 @cindex CHRP partition, _definition
 @strong{chrp_boot_part=on} causes a single partition in MBR which covers
 the whole ISO image and has type 0x96. This is not compatible with any
@@ -5000,6 +5021,9 @@ If the number of preceding partitions is too high, then a NOTE message informs
 about the inability to achieve partition_number and about the actually assigned
 number.
 @*
+The chance to get the desired partition number is increased much by
+command -boot_image "any" "appended_gpt_with_gaps=on".
+@*
 The type_code may be the same as described with MBR. Given GUIDs are used
 unchanged. Given MBR partition types get translated. 0xef becomes
 C12A7328-F81F-11D2-BA4B-00A0C93EC93B, others become