Re: Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable

[Alexander E. Patrakov]

21.12.2015 23:46, Andrei Borzenkov пишет:
> Yes, that may be an option. Still, using GPT is known to work; and those
> implementations I am aware of ignore MBR if partition 0xee is present.
> So it still looks like adding dummy bootable partition to MBR is the
> least evil.

So, I have just tested a few variants of this on DG965SS (BIOS boot from 
USB flash drive). I will keep my promise and make a VM with the latest 
git of GRUB and xorriso later today.

The base image is http://82.193.153.141/minimal-type0.iso , which has 
two partitions, one of type ee, and the other of type 0 and bootable, 
occupying the same sectors:

000001b0: b47b 0000 0000 0000 0000 0000 0000 0000  .{..............
000001c0: 0200 ee02 1410 0100 0000 5380 0000 8000  ..........S.....
000001d0: 0200 0002 1410 0100 0000 5380 0000 0000  ..........S.....
000001e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001f0: 0000 0000 0000 0000 0000 0000 0000 55aa  ..............U.

The following variants, obtained by changing only the MBR, also work:

1. Type-0 one-sector bootable partition at the very first sector:

000001b0: b47b 0000 0000 0000 0000 0000 0000 0000  .{..............
000001c0: 0200 ee02 1410 0100 0000 5380 0000 8000  ..........S.....
000001d0: 0100 0000 0200 0000 0000 0100 0000 0000  ................
000001e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001f0: 0000 0000 0000 0000 0000 0000 0000 55aa  ..............U.

2. Type-b0 one-sector bootable partition at the very first sector:

000001b0: b47b 0000 0000 0000 0000 0000 0000 0000  .{..............
000001c0: 0200 ee02 1410 0100 0000 5380 0000 8000  ..........S.....
000001d0: 0100 b000 0200 0000 0000 0100 0000 0000  ................
000001e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001f0: 0000 0000 0000 0000 0000 0000 0000 55aa  ..............U.

3. Type-b0 one-sector bootable partition at the end:

000001b0: b47b 0000 0000 0000 0000 0000 0000 0000  .{..............
000001c0: 0200 ee02 1410 0100 0000 5380 0000 8001  ..........S.....
000001d0: 8d23 b001 8d23 5480 0000 0100 0000 0000  .#...#T.........
000001e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001f0: 0000 0000 0000 0000 0000 0000 0000 55aa  ..............U.

If you want me to test anything else specific, please ask.

--
Alexander E. Patrakov