Request for review of attached patches for hybrid GPT/MBR

[David Joshua Geary]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

with aim for inclusion in mainline Grub2.

Grub2 1.99 is base. Patches to gpt.c and msdos.c in /grub-core/partmap/.

Diffs attached with original code and patched code.

Goal: To make the disk bootable on: PCs using BIOS, PCs using UEFI,
Intel Macintoshes using BIOS, and Intel Macintoshes using EFI, as well
as having the (HybridData) partition readable by both Windows and MacOSX.

ExaExample partition layout:mple partition layout:

Physical: MBR GPT (HybridData) (EFI) (BIOS)
MBR:
1: 0C (FAT32) : FAT32 (HybridData)
2: EF (EFI) : FAT32 (EFI)
3: EE (GPT) : (Protective)
GPT:
1: 0700 (Data) : FAT32 (HybridData)
2: ef00 (EFI) : FAT32 (EFI)
3: 0f02 (BIOS) : Unformatted (BIOS)

Current behaviour:

Grub2 detects an MBR and checks if the first MBR primary partition is
GPT protective partition. The first MBR primary partition is not a GPT
protective partition, so it treats the disk as a pure MBR disk and so
refuses to install the boot loader kernel in the post-MBR gap because
there is no post-MBR gap because it is taken by GPT protective partition.

Proposed behaviour:

Grub2 detects an MBR and checks if any of the MBR primary partitions are
GPT protective partitions. It finds a GPT protective partition (MBR
primary partition 3 in the example), and concludes that the disk is a
GPT disk and looks for a BIOS boot partition (Hah!IdontNeedEFI) (GPT
partition 3 in the example) in which to install the boot loader kernel.

Questions, Comments, and Feedback welcome.

See also: http://perditauranus.dyndns.org/tdiary/?date=20110803
See also: http://www.rodsbooks.com/gdisk/hybrid.html#bootloaders

- -- 
David Joshua Geary
UNE Linux User Group: address@hidden <http://lugune.dyndns.org>
I don't care what software you use so long as
  we only exchange files in open data formats
Open-Document <http://en.wikipedia.org/wiki/Open_Document>
Ogg <http://en.wikipedia.org/wiki/Ogg>
PDF <http://en.wikipedia.org/wiki/Pdf>

- -----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.4.10 (GNU/Linux)
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=kv+y
- -----END PGP PUBLIC KEY BLOCK-----
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
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=/0rL
-----END PGP SIGNATURE-----

gpt.c
Description: Text Data

gpt.c.diff
Description: Text Data

gpt.c.original
Description: Text document

msdos.c
Description: Text Data

msdos.c.diff
Description: Text Data

msdos.c.original
Description: Text document

gpt.c.sig
Description: PGP signature

gpt.c.diff.sig
Description: PGP signature

gpt.c.original.sig
Description: PGP signature

msdos.c.sig
Description: PGP signature

msdos.c.diff.sig
Description: PGP signature

msdos.c.original.sig
Description: PGP signature