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#380055
This how-to is written for people like me !!
that is if you have ever wiped out your partition table and the only form you have is a hexdump of it.
You can do this to regain it and install it back this worked for me.
Say the only representation of your partition table + mbr WHICH you have
wiped out
is
00000000 fa eb 21 01 b2 01 4c 49 4c 4f 16 07 bb 65 c3 45 |úë!.².LILO..»eÃE|
00000010 00 00 00 00 57 b9 e5 01 30 a3 28 6e 81 00 80 60 |....W¹å.0£(n...`|
00000020 1f 06 8c 02 b8 c0 07 8e d0 bc 00 08 fb 52 53 06 |....¸À..м..ûRS.|
00000030 56 fc 8e d8 31 ed 60 b8 00 12 b3 36 cd 10 61 b0 |Vü.Ø1í`¸..³6Í.a°|
00000040 0d e8 64 01 b0 0a e8 5f 01 b0 4c e8 5a 01 60 1e |.èd.°.è_.°LèZ.`.|
00000050 07 80 fa fe 75 02 88 f2 bb 00 02 8a 76 1e 89 d0 |..úþu..ò»...v..Ð|
00000060 80 e4 80 30 e0 78 0a 3c 10 73 06 f6 46 1c 40 75 |.ä.0àx.<.s.öF.@u|
00000070 2e 88 f2 66 8b 76 18 66 09 f6 74 23 52 b4 08 b2 |..òf.v.f.öt#R´.²|
00000080 80 53 cd 13 5b 72 57 0f b6 ca ba 7f 00 42 66 31 |.SÍ.[rW.¶Êº..Bf1|
00000090 c0 40 e8 60 00 66 3b b7 b8 01 74 03 e2 ef 5a 53 |À@è`.f;·¸.t.âïZS|
000000a0 8a 76 1f be 20 00 e8 dd 00 b4 99 66 81 7f fc 4c |.v.¾ .èÝ.´.f..üL|
000000b0 49 4c 4f 75 29 5e 68 80 08 07 31 db e8 c7 00 75 |ILOu)^h...1ÛèÇ.u|
000000c0 fb be 06 00 89 f7 b9 0a 00 b4 9a f3 a6 75 0f b0 |û¾...÷¹..´.ó¦u.°|
000000d0 02 ae 75 0a 06 55 b0 49 e8 cd 00 cb b4 40 b0 20 |.®u..U°IèÍ.Ë´@° |
000000e0 e8 c5 00 e8 b2 00 fe 4e 00 74 07 bc e8 07 61 e9 |èÅ.è².þN.t.¼è.aé|
000000f0 5c ff f4 eb fd 60 55 55 66 50 06 53 6a 01 6a 10 |\ÿôëý`UUfP.Sj.j.|
00000100 89 e6 53 f6 c6 60 74 6e f6 c6 20 74 14 bb aa 55 |.æSöÆ`tnöÆ t.»ªU|
00000110 b4 41 cd 13 72 0b 81 fb 55 aa 75 05 f6 c1 01 75 |´AÍ.r..ûUªu.öÁ.u|
00000120 3f 52 06 b4 08 cd 13 07 72 b4 51 c0 e9 06 86 e9 |?R.´.Í..r´QÀé..é|
00000130 89 cf 59 c1 ea 08 92 40 83 e1 3f f7 e1 93 8b 44 |.ÏYÁê..@.á?÷á..D|
00000140 08 8b 54 0a 39 da 73 94 f7 f3 39 f8 77 8e c0 e4 |..T.9Ús.÷ó9øw.Àä|
00000150 06 86 e0 92 f6 f1 08 e2 89 d1 41 5a 88 c6 eb 1c |..à.öñ.â.ÑAZ.Æë.|
00000160 b4 42 5b bd 05 00 60 cd 13 73 16 4d 74 ba 31 c0 |´B[½..`Í.s.Mtº1À|
00000170 cd 13 61 4d eb f0 66 50 59 58 88 e6 b8 01 02 eb |Í.aMëðfPYX.æ¸..ë|
00000180 e1 8d 64 10 61 c3 66 ad 66 09 c0 74 0a 66 03 46 |á.d.aÃff.Àt.f.F|
00000190 10 e8 61 ff 80 c7 02 c3 c1 c0 04 e8 03 00 c1 c0 |.èaÿ.Ç.ÃÁÀ.è..ÁÀ|
000001a0 04 24 0f 27 04 f0 14 40 60 bb 07 00 b4 0e cd 10 |.$.'.ð.@`»..´.Í.|
000001b0 61 c3 00 00 00 00 4d 7f 30 a3 28 6e cf c9 80 01 |aÃ....M.0£(nÏÉ..|
000001c0 01 00 0c 0f ff ff 3f 00 00 00 91 10 2a 01 00 0f |....ÿÿ?.....*...|
000001d0 ff ff 83 0f ff ff c0 14 2a 01 02 e2 1a 01 00 0f |ÿÿ..ÿÿÀ.*..â....|
000001e0 ff ff 83 0f ff ff 00 0a 54 02 90 1d 1b 01 00 0f |ÿÿ..ÿÿ..T.......|
000001f0 ff ff 05 0f ff ff 90 27 6f 03 e0 8d 39 01 55 aa |ÿÿ..ÿÿ.'o.à.9.Uª|
00000200
please take into note that
Note: An MBR has 3 parts:
1. (000000 - 0001bd) The boot code which is 446 bytes long
2. (0001be - 0001fd) The partition table which is 64 bytes long
3. (0001fe - 0001ff) The boot code signature of 55aa which is 2 bytes long and goes at the very end
so they way to go is to convert the hexademical code back to binary form and copy that file back to the MBR .
the hex code is the "fa eb 21 01 b2 01 4c 49 4c 4f 16 07 bb 65 c3 45" ------> ascii--> |úë!.².LILO..»eÃE|
1) you have to get rid of the 1st colum and the ascii presentation on the right
you do
agiofws@celeron3~
$cat ddTable | cut -c 11-58
fa eb 21 01 b2 01 4c 49 4c 4f 16 07 bb 65 c3 45
00 00 00 00 57 b9 e5 01 30 a3 28 6e 81 00 80 60
1f 06 8c 02 b8 c0 07 8e d0 bc 00 08 fb 52 53 06
56 fc 8e d8 31 ed 60 b8 00 12 b3 36 cd 10 61 b0
0d e8 64 01 b0 0a e8 5f 01 b0 4c e8 5a 01 60 1e
07 80 fa fe 75 02 88 f2 bb 00 02 8a 76 1e 89 d0
80 e4 80 30 e0 78 0a 3c 10 73 06 f6 46 1c 40 75
2e 88 f2 66 8b 76 18 66 09 f6 74 23 52 b4 08 b2
80 53 cd 13 5b 72 57 0f b6 ca ba 7f 00 42 66 31
c0 40 e8 60 00 66 3b b7 b8 01 74 03 e2 ef 5a 53
8a 76 1f be 20 00 e8 dd 00 b4 99 66 81 7f fc 4c
49 4c 4f 75 29 5e 68 80 08 07 31 db e8 c7 00 75
fb be 06 00 89 f7 b9 0a 00 b4 9a f3 a6 75 0f b0
02 ae 75 0a 06 55 b0 49 e8 cd 00 cb b4 40 b0 20
e8 c5 00 e8 b2 00 fe 4e 00 74 07 bc e8 07 61 e9
5c ff f4 eb fd 60 55 55 66 50 06 53 6a 01 6a 10
89 e6 53 f6 c6 60 74 6e f6 c6 20 74 14 bb aa 55
b4 41 cd 13 72 0b 81 fb 55 aa 75 05 f6 c1 01 75
3f 52 06 b4 08 cd 13 07 72 b4 51 c0 e9 06 86 e9
89 cf 59 c1 ea 08 92 40 83 e1 3f f7 e1 93 8b 44
08 8b 54 0a 39 da 73 94 f7 f3 39 f8 77 8e c0 e4
06 86 e0 92 f6 f1 08 e2 89 d1 41 5a 88 c6 eb 1c
b4 42 5b bd 05 00 60 cd 13 73 16 4d 74 ba 31 c0
cd 13 61 4d eb f0 66 50 59 58 88 e6 b8 01 02 eb
e1 8d 64 10 61 c3 66 ad 66 09 c0 74 0a 66 03 46
10 e8 61 ff 80 c7 02 c3 c1 c0 04 e8 03 00 c1 c0
04 24 0f 27 04 f0 14 40 60 bb 07 00 b4 0e cd 10
61 c3 00 00 00 00 4d 7f 30 a3 28 6e cf c9 80 01
01 00 0c 0f ff ff 3f 00 00 00 91 10 2a 01 00 0f
ff ff 83 0f ff ff c0 14 2a 01 02 e2 1a 01 00 0f
ff ff 83 0f ff ff 00 0a 54 02 90 1d 1b 01 00 0f
ff ff 05 0f ff ff 90 27 6f 03 e0 8d 39 01 55 aa
2) to get rid of the white space just to be sure to get an accurate MBR
$cat ddTable2 | tr -d '[[:space:]]'
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
3) so now we are ready to convert it back to its original state
for this task we use xxd with the -r and the -p otion
agiofws@celeron3~
$cat ddTable3 | xxd -p -r
èd°²LILO»eÃEW¹å0£(n`¸ÀÐûRSVüØ1í`¸³6Ía°
è_°LèZ`úþuò»vÐä0àx
<söF@u.òfvf öt#R²SÍ[rW¶ÊºBf1À@è`f;·¸tâïZSv¾ èÝ´füLILOu)^h1ÛèÇuû¾÷¹
´ó¦u°®u
U°IèÍË´@° èÅè²þNt¼èaé\ÿôëý`UUfPSjjæSöÆ`tnöÆ t»ªU´AÍr
ûUªuöÁu?RÍr´QÀééÏYÁ@á?÷áT
9Ús÷ó9øwÀäàöâÑAZÆë´B[½`ÍsMtº1ÀÍaMëðfPYXæ¸ëádaÃff Àt
fFèaÿÇÃÁÀèÁÀ$'ð@`»´ÍaÃM0£(nÏÉ
ÿÿ?*ÿÿÿÿÀ*âÿÿÿÿ
Tÿÿÿÿ'oà9Uª
we save the ouput to ddTable4
agiofws@celeron3~
$cat ddTable3 | xxd -p -r > ddTable4
4) to check if the above output is exaclty tha same as the first table up TOP we can do
agiofws@celeron3~
$dd if=ddTable4 | hexdump -C
1+0 records in
1+0 records out
512 bytes (512 B) copied, 0.000131539 seconds, 3.9 MB/s
00000000 fa eb 21 01 b2 01 4c 49 4c 4f 16 07 bb 65 c3 45 |úë!.².LILO..»eÃE|
00000010 00 00 00 00 57 b9 e5 01 30 a3 28 6e 81 00 80 60 |....W¹å.0£(n...`|
00000020 1f 06 8c 02 b8 c0 07 8e d0 bc 00 08 fb 52 53 06 |....¸À..м..ûRS.|
00000030 56 fc 8e d8 31 ed 60 b8 00 12 b3 36 cd 10 61 b0 |Vü.Ø1í`¸..³6Í.a°|
00000040 0d e8 64 01 b0 0a e8 5f 01 b0 4c e8 5a 01 60 1e |.èd.°.è_.°LèZ.`.|
00000050 07 80 fa fe 75 02 88 f2 bb 00 02 8a 76 1e 89 d0 |..úþu..ò»...v..Ð|
00000060 80 e4 80 30 e0 78 0a 3c 10 73 06 f6 46 1c 40 75 |.ä.0àx.<.s.öF.@u|
00000070 2e 88 f2 66 8b 76 18 66 09 f6 74 23 52 b4 08 b2 |..òf.v.f.öt#R´.²|
00000080 80 53 cd 13 5b 72 57 0f b6 ca ba 7f 00 42 66 31 |.SÍ.[rW.¶Êº..Bf1|
00000090 c0 40 e8 60 00 66 3b b7 b8 01 74 03 e2 ef 5a 53 |À@è`.f;·¸.t.âïZS|
000000a0 8a 76 1f be 20 00 e8 dd 00 b4 99 66 81 7f fc 4c |.v.¾ .èÝ.´.f..üL|
000000b0 49 4c 4f 75 29 5e 68 80 08 07 31 db e8 c7 00 75 |ILOu)^h...1ÛèÇ.u|
000000c0 fb be 06 00 89 f7 b9 0a 00 b4 9a f3 a6 75 0f b0 |û¾...÷¹..´.ó¦u.°|
000000d0 02 ae 75 0a 06 55 b0 49 e8 cd 00 cb b4 40 b0 20 |.®u..U°IèÍ.Ë´@° |
000000e0 e8 c5 00 e8 b2 00 fe 4e 00 74 07 bc e8 07 61 e9 |èÅ.è².þN.t.¼è.aé|
000000f0 5c ff f4 eb fd 60 55 55 66 50 06 53 6a 01 6a 10 |\ÿôëý`UUfP.Sj.j.|
00000100 89 e6 53 f6 c6 60 74 6e f6 c6 20 74 14 bb aa 55 |.æSöÆ`tnöÆ t.»ªU|
00000110 b4 41 cd 13 72 0b 81 fb 55 aa 75 05 f6 c1 01 75 |´AÍ.r..ûUªu.öÁ.u|
00000120 3f 52 06 b4 08 cd 13 07 72 b4 51 c0 e9 06 86 e9 |?R.´.Í..r´QÀé..é|
00000130 89 cf 59 c1 ea 08 92 40 83 e1 3f f7 e1 93 8b 44 |.ÏYÁê..@.á?÷á..D|
00000140 08 8b 54 0a 39 da 73 94 f7 f3 39 f8 77 8e c0 e4 |..T.9Ús.÷ó9øw.Àä|
00000150 06 86 e0 92 f6 f1 08 e2 89 d1 41 5a 88 c6 eb 1c |..à.öñ.â.ÑAZ.Æë.|
00000160 b4 42 5b bd 05 00 60 cd 13 73 16 4d 74 ba 31 c0 |´B[½..`Í.s.Mtº1À|
00000170 cd 13 61 4d eb f0 66 50 59 58 88 e6 b8 01 02 eb |Í.aMëðfPYX.æ¸..ë|
00000180 e1 8d 64 10 61 c3 66 ad 66 09 c0 74 0a 66 03 46 |á.d.aÃff.Àt.f.F|
00000190 10 e8 61 ff 80 c7 02 c3 c1 c0 04 e8 03 00 c1 c0 |.èaÿ.Ç.ÃÁÀ.è..ÁÀ|
000001a0 04 24 0f 27 04 f0 14 40 60 bb 07 00 b4 0e cd 10 |.$.'.ð.@`»..´.Í.|
000001b0 61 c3 00 00 00 00 4d 7f 30 a3 28 6e cf c9 80 01 |aÃ....M.0£(nÏÉ..|
000001c0 01 00 0c 0f ff ff 3f 00 00 00 91 10 2a 01 00 0f |....ÿÿ?.....*...|
000001d0 ff ff 83 0f ff ff c0 14 2a 01 02 e2 1a 01 00 0f |ÿÿ..ÿÿÀ.*..â....|
000001e0 ff ff 83 0f ff ff 00 0a 54 02 90 1d 1b 01 00 0f |ÿÿ..ÿÿ..T.......|
000001f0 ff ff 05 0f ff ff 90 27 6f 03 e0 8d 39 01 55 aa |ÿÿ..ÿÿ.'o.à.9.Uª|
as we can see indeed it is :)
now the only thing to do is to copy the partition table BACK to its place so you can start using you disk again
so all we do is
dd if=ddTable4 of=/dev/hda bs=512 count=1
and now hopefully you will be able to boot from your drive
* i was told that to recover from a wiped out partition table you can use parted or Qparted which
seeks out previous entries of your partition table
good luck :)