Re: [PATCH] gptsync

On Wed, Apr 22, 2009 at 1:10 AM, Vladimir Serbinenko <address@hidden> wrote:

On Tue, Apr 21, 2009 at 1:29 PM, Peter Cros <address@hidden> wrote:

Hi,

I have been playing with grub gptsync, on apple intel mac with GUID partitioned 8 GB usb stick, 8 partitions. #1 is the standard fat32 EFI system part for macs.

I am comparing with the gptsync utility from linux, or rEFIt gptsync, currently used for macs booting pc-bios bootloader.

It is working to allow selection of GPT partions for MBR 2, 3, 4 but some of the numbers look wrong. I have not tried setting flags.

grub gptsync is not handling MBR partition table 1 the same way as current linux or refit gptsync, which puts GPT partition 1 (EFI system FAT32) in MBR part1.

I don't understand what you mean. I will not do any special treatment for EFI system partition. As far as I'm concerned it's just a partition. I don't think it's a problem since user can ask which partitions to put in MBR

GPT Partions are
(512 byte sectors)

Current GPT partition table:
# Start LBA End LBA Type
1 40 409639 EFI System (FAT)

2 409640 2395367 Mac OS X HFS+
3 2395368 4573255 Mac OS X HFS+
4 4835400 7141399 Mac OS X HFS+
5 7403544 9965767 Mac OS X HFS+

6 10227912 13046359 Mac OS X HFS+
7 13308504 15642623 Mac OS X HFS+
8 15904768 15949783 Mac OS X HFS+

There seems to be agreement about start and end on MBR table partitions 2 3 4, using grub> gptsync (hd0) 2 3 4.

Other bytes differ (type, flags).

This is after grub> gptsync (hd0) 2 3 4
(MBR part1 was initially set by linux gptsync)

address@hidden:~$ sudo hexdump -Cn80 -s432 /dev/sdb

[sudo] password for pxw:
000001b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000001c0 02 00 ee 7f 0e 19 01 00 00 00 27 40 06 00 00 7f |..........'@....|
000001d0 0f 19 83 1a 2d 95 28 40 06 00 c0 4c 1e 00 00 1a |....-.(@...L....|
000001e0 2e 95 83 ab 57 1c e8 8c 24 00 60 3b 21 00 00 fc |....W...$.`;!...|
000001f0 59 2c 83 87 63 bc 48 c8 49 00 d0 2f 23 00 55 aa |Y,..c.H.I../#.U.|

00000200

Then as seen in linux gptsync,

Current MBR partition table:
# A Start LBA End LBA Type
1 1 409639 ee EFI Protective

2 409640 2395367 83 Linux
3 2395368 4573255 83 Linux
4 4835400 7141399 83 Linux

Status: MBR table must be updated.

Proposed new MBR partition table:
# A Start LBA End LBA Type
1 1 409639 ee EFI Protective
2 * 409640 2395367 af Mac OS X HFS+

3 2395368 4573255 af Mac OS X HFS+
4 4835400 7141399 af Mac OS X HFS+
May I update the MBR as printed above? [y/N] y
Yes

Here there are 2 differences. First partition type for hfs+ isn't autodetected, I will fix this, just I thought it ws unnecessary AFAIK every OS which understands HFS+ understands GPT. The second thing is that none of partiion is active. Here you have just to tell which partition is active. You can have the same behavior as OSX gptsync with command
gptsync hd0 2+0xaf 3-0xaf 4-0xaf
Once I add hfs+ autodetect it will be enough to do

gptsync hd0 2+ 3 4

address@hidden:~$ sudo hexdump -Cn80 -s432 /dev/sdb

000001b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fe |................|
000001c0 ff ff ee fe ff ff 01 00 00 00 27 40 06 00 80 fe |..........'@....|
000001d0 ff ff af fe ff ff 28 40 06 00 c0 4c 1e 00 00 fe |......(@...L....|

000001e0 ff ff af fe ff ff e8 8c 24 00 60 3b 21 00 00 fe |........$.`;!...|
000001f0 ff ff af fe ff ff 48 c8 49 00 d0 2f 23 00 55 aa |......H.I../#.U.|
00000200

--
Cros (pxw)

_______________________________________________
Grub-devel mailing list
address@hidden
http://lists.gnu.org/mailman/listinfo/grub-devel

_______________________________________________
Grub-devel mailing list
address@hidden
http://lists.gnu.org/mailman/listinfo/grub-devel

From:	Peter Cros
Subject:	Re: [PATCH] gptsync
Date:	Wed, 22 Apr 2009 04:02:51 +1000