Added an overview table to EFI isohybrid description.

This commit is contained in:
Thomas Schmitt 2012-05-06 14:11:34 +02:00
parent abd2137906
commit dc2b27ca51
1 changed files with 33 additions and 1 deletions

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@ -102,7 +102,7 @@ Defined by El Torito are:
0 = "80x86" which is used for standard PCs with Intel x86 or compatible CPU
1 = "PowerPC" (possibly for IBM machines with PowerPC CPU)
2 = "Mac" (possibly for Apple computers with MC68000 or PowerPC CPU)
Further in use by GRUB2 is:
Further in use by GRUB2 and ISOLINUX is:
0xef = EFI, a competitor resp. successor to PC-BIOS, possibly in use with
Intel ia64 Itanium and possibly with newer Apple machines.
@ -408,6 +408,38 @@ Sources:
>>> Motivation: What systems will use the additional data ? amd64 UEFI ?
This is a very condensed format which exposes as many entry points for boot
firmware as possible.
Byte Range | Value | Meaning (all numbers are stored big endian)
-------------- | ---------- | -------------------------------------------------
0 - 511 | mbr | Isohybrid MBR pointing to x86 boot image file,
| | with three entries in its partition map.
| | It shares its first 32 bytes with apm_head.
0 - 31 | apm_head | Mock-up of the start of the first block of
| | an Apple Partition Map (APM).
446 - 461 | mbr_entry1 | Partition table entry 1 describing ISO image size
462 - 477 | mbr_entry2 | Entry 2 describing the UEFI VFAT boot image.
478 - 493 | mbr_entry3 | Entry 3 describing the HFS+ boot image.
| |
512 - 1023 | gpt_head | GPT header describing the GPT partition array.
1024 - 2047 | unused |
2048 - 4095 | apm_entry1 | APM entry 1 describing ISO image size.
4096 - 6143 | apm_entry2 | APM entry 2 describing the UEFI VFAT boot image.
6144 - 8195 | apm_entry3 | APM entry 2 describing the HFS+ boot image.
8192 - 8319 | gpt_entry1 | GPT partition entry 1 for the ISO image size.
8320 - 8447 | gpt_entry2 | GPT partition entry 2 for UEFI VFAT boot image,
8448 - 8575 | gpt_entry3 | GPT partition entry 3 for the HFS+ boot image.
8576 - 24575 | gtp_empty | Empty GPT partition entries 4 to 128.
24576 - 32767 | unused |
32768 - 34815 | iso_pvd | ISO 9660 superblock
34815 - 36863 | el_torito | EL Torito boot block pointing to a boot catalog
| | with entries for the MBR boot image (platform
| | 0x00), and for the two other boot images
| | (platform id 0xef)
-------------- | ---------- | -------------------------------------------------
Newer SYSLINUX MBR templates begin by 32 bytes of machine code which are
intentionally non-essential:
33 ed 90 90 90 90 90 90 90 90 90 90 90 90 90 90