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Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partitio
From: |
Thomas Schmitt |
Subject: |
Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable |
Date: |
Tue, 22 Dec 2015 16:05:33 +0100 |
Hi,
Alexander E. Patrakov wrote:
> The following variants, obtained by changing only the MBR, also work:
> 1. Type-0 one-sector bootable partition at the very first sector:
> 000001d0: 0100 0000 0200 0000 0000 0100 0000 0000 ................
Did you create this by partition editor or by dd ?
While trying to mimick it, i wonder whether the "0200" should
not be "0100". I understand that the value "02" is in byte 468 = 0x1d4:
Sector part of C/H/S address of last absolute sector in partition 2.
(Plus 2 bits from cylinder part which are 0.)
A partition from LBA 0 with 1 blocks should have C/H/S range
0/0/1 to 0/0/1, not 0/0/1 to 0/0/2.
(I am not sure how to express the end C/H/S of an empty partition
at LBA 0. 0/0/0 is not really a valid C/H/S.)
------------------------------------------------------------------
There is a new GNU xorriso development snapshot uploaded
http://www.gnu.org/software/xorriso/xorriso-1.4.3.tar.gz
MD5 5163f97f5ce9a7707ac7de6777b46283
For a proof-of-concept i have added two macros which enable
the production of a dummy MBR partition like with Alexander's
recent experiments.
To be unpacked and built by
tar xzf xorriso-1.4.3.tar.gz
cd xorriso-1.4.3 && ./configure && make
Test the executable standalone binary by
xorriso/xorriso -version
which should yield
...
xorriso version : 1.4.3
Version timestamp : 2015.12.22.133736
...
You may use it by its absolute address with grub-mkrescue --xorriso=...
I hopefully fixed the bug with partition type 0xee with HFS+ if
no GPT emerges. It should now be 0x83 or 0xcd depending on the
presence of option --protective-msdos-label .
Test proposals with add-on partition of type 0x00:
- Variation 1
In ./xorriso-1.4.3 do
export CPPFLAGS=" -DLibisofs_protective_msdos_plus_boot_dummY"
./configure && make clean && make
If option --protective-msdos-label is present, and there emerges
only one partition of type 0xee with no boot flag, then a second
MBR partition gets addedd with same geometry as the first one,
but with type 0x00 and boot flag.
MBR partition table: N Status Type Start Blocks
MBR partition : 1 0x00 0xee 1 32251
MBR partition : 2 0x80 0x00 1 33251
- Variation 2
In ./xorriso-1.4.3 do
export CPPFLAGS=" -DLibisofs_protective_msdos_plus_boot_dummY"
CPPFLAGS="$CPPFLAGS -DLibisofs_pmpbd_on_lba0"
./configure && make clean && make
Under the same criteria as with Variation 1, the added second MBR
partition starts at LBA and has only 1 block.
MBR partition table: N Status Type Start Blocks
MBR partition : 1 0x00 0xee 1 32251
MBR partition : 2 0x80 0x00 0 1
- Back to normal
In ./xorriso-1.4.3 do
unset CPPFLAGS
./configure && make clean && make
I would be thankful for reports about tests with grub-mkrescue
and the picky machines.
(The partition adder code is on display at
http://bazaar.launchpad.net/~libburnia-team/libisofs/scdbackup/revision/1296/libisofs/system_area.c
)
Have a nice day :)
Thomas
- Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable, (continued)
- Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable, Thomas Schmitt, 2015/12/20
- Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable, Thomas Schmitt, 2015/12/20
- Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable, Andrei Borzenkov, 2015/12/20
- Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable, Thomas Schmitt, 2015/12/21
- Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable, Andrei Borzenkov, 2015/12/21
- Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable, Thomas Schmitt, 2015/12/21
- Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable, Alexander E. Patrakov, 2015/12/21
- Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable, Thomas Schmitt, 2015/12/21
- Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable, Alexander E. Patrakov, 2015/12/21
- Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable, Alexander E. Patrakov, 2015/12/22
- Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable,
Thomas Schmitt <=
- Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable, Alexander E. Patrakov, 2015/12/22
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