New -boot_image bootspec appended_gpt_with_gaps=

xorriso/xorriso.1

@@ -9,7 +9,7 @@
 .\" First parameter, NAME, should be all caps
 .\" Second parameter, SECTION, should be 1-8, maybe w/ subsection
 .\" other parameters are allowed: see man(7), man(1)
-.TH XORRISO 1 "Version 1.5.7, Nov 01, 2024"
+.TH XORRISO 1 "Version 1.5.7, Dec 08, 2024"
 .\" Please adjust this date whenever revising the manpage.
 .\"
 .\" Some roff macros, for reference:
@@ -4019,7 +4019,7 @@ Command \-volume_date "uuid" can be used to set their value.
 .br
 \fBbin_path=\fR 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.
 .br
 \fBefi_path=\fR depicts an El Torito boot image file that is ready for
 EFI booting. This is normally a FAT filesystem image not larger than
@@ -4032,9 +4032,12 @@ It controls the boot medium emulation code of a boot image.
 The default "no_emulation" is suitable for ISOLINUX, GRUB, FreeBSD cdboot.
 .br
 \fBload_size=\fR 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.
 .br
 \fBboot_info_table=on\fR causes address patching to bytes 8 to 63
 of the boot image which is given by "any" "bin_path=".
@@ -4188,6 +4191,23 @@ 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".
 .br
+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.
+.br
+\fBappended_gpt_with_gaps=on\fR 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.
+.br
+\fBappended_gpt_with_gaps=off\fR 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.
+.br
 \fBchrp_boot_part=on\fR causes a single partition in MBR which covers
 the whole ISO image and has type 0x96. This is not compatible with any
 other feature that produces MBR partition entries. It makes GPT unrecognizable.
@@ -4400,6 +4420,9 @@ 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.
 .br
+The chance to get the desired partition number is increased much by
+command \-boot_image "any" "appended_gpt_with_gaps=on".
+.br
 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