14 replies to this topic

[DavidB]

Hi.
Sorry in advance for my bad english and because of my lack of technical terms...
So please be patient with me...

For some time I use Grub4Dos to boot into Windows and Linux on my internal HDD but also on my flash drive.
I have 0.45c version (I understand that it's the newest stable version).

My questions are:
1. I see that, in download section, grub4dos-0.4.5c-2013-02-02-2.7z has a "Featured" label near it. What does it mean...?
2. I understand that it's better to install Grub4Dos in MBR, not in PBR. But I prefer the PBR... This is how I had for both internal HDD and flash drive for some time without problems. But recently the MBR of the flash drive got overwritten by a Windows 7 MBR (it's a long story) and, because I didn't know how to restore the old one, I installed Grub4Dos in MBR. Since then it's causing some problems loading Linux from the internal HDD (when the flash drive is attached to a USB port). I think the problem is with the Linux distro, not with Grub4Dos or the menu.lst file from the internal HDD. But, since it's a lot harder to modify the Linux distro, my question is: how can I install the normal MBR back (who would load Grub4Dos from PBR)...? Preferably without formatting the flash drive...
3. Is there a way to find a file (in a specific location) when you know only a portion of the name? And the result to be passed as parameter for other function...?
For example: search for /NTD*.COM in a partition and it will find /NTDETECT.COM, who will be used by, let's say, chainloader function. (it's just an example, the name of the file and the name of the function were randomly chosen).
More: if more than 1 file is found, to return the file name which meets certain condition(s). For example, if you search File* and there are File01 and File02 at that location, to return File01 if you want the lowest, File02 if you want the highest. Or, better, it could return 01 or 02 so you can use it to "build" a name for other function...

Could you please help me with these...?
Thank you.

Regards, David

[steve6375]

1. Featured means 'released' - good to use, latest version

2. RMPrepUSB will put standard MBR code (vista/7) - alternatively sector 2 (LBA 1) usually has a backup of the original MBR.

3. Not really. I have written some batch files to find  filename or extension - see here - they return the first match found.

[DavidB]

Thank you, steve6375.

1. Ok, I will use it then.
2. I know about RMPrepUSB, I tried to use it a few times but:
a) It's possible to do it without formatting the drive? Because I have a lot of iso's on my flash drive and it will take a very long time to copy them back + it will shorten its "life"...
b) When I had that Windows 7 MBR, it said something "could not find bootmgr". You're saying to install "standard" Vista/7 MBR, but what is the difference between this and the one that I described (since they have somehow the same name)?
c) How to restore the backup of the original MBR from sector 2 (LBA 1)?
3. I understand. Maybe in the future will be implemented directly in grub4dos.
An example how can be used: we could have menu entries who will automatically load a Linux distro, no matter which kernel version has.
I use this menu entry to load Linux on my internal HDD:

title start Linux
root (hd0,1)
kernel /boot/vmlinuz-3.7.6-201 root=/dev/sda2 [other_parameters]
initrd /boot/initramfs-3.7.6-201.img

But if I upgrade the kernel I had to change here too. Instead I could use that search to find any "/boot/vmlinuz-*" and "/boot/initramfs-*.img". With some additional commands I could make it load from any partition (just like in your example "Boot from Hard Drive - Windows Vista/7 (BOOTMGR)").
Just an idea...

Regards, David

Edited by DavidB, 14 February 2013 - 12:03 PM.

[steve6375]

2. Use latest RMPrepUSB - Bootloaders tab - Install Std MBR - does not destroy paritition table - just replaces MBR boot code. You can swap between grub4dos and standard MBR easily using this and the 'Install grub4dos' button.

 

I think you are confusing MBR and PBR.

MBR is in first sector of disk. It contains code which just gets the start sector of the active partition from the partition table (which is also in the MBR) and then loads that first sector of that partition into memory. This first partition sector is the Partition Boot Record.

PBR is the first sector at the start of a partition which contains bootloader code. Normally. it's task is to search the partition for a bootloader (like ntldr, bootmgr, etc) and load it into memory and execute the code.

 

3. Simplest thing to do is just boot direct from the ISO. See Easy2Boot on my site. Just put the ISO in a folder and you can boot it. 99% of linux ISOs just work!

Of course, if you want to modify it (add cheat codes) then you will need to write a menu.

[steve6375]

To restore the backup, you first need to check it is there!

In RMPrepUSB - run  Drive Info, Start=0  - see if code in LBA0 is grub4dos (should be) and code in LBA1 (the second sector) is standard MBR (look at error messages near end of sector).

Also check that table that begins at 1BE to 1FF  (and 3BE-3FF) is same in both sectors - this is the partition table.

report back...

[DavidB]

2. I knew about the difference between MBR and PBR, but I wasn't completely sure that PBR is loaded by the MBR.
Why? Because that Windows 7 boot seemed strange. I tried to install grub4dos again in PBR, it didn't work (no difference).

 

============= SECTOR DATA ================

[Sector 0]  0MB
0000 33 C0 EB 5C 81 00 20 39 - FF FF 00 00 00 00 00 00  3Ŕë\. 9 ˙˙......
0010 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00  ........ ........
0020 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00  ........ ........
0030 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00  ........ ........
0040 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00  ........ ........
0050 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00  ........ ........
0060 E8 00 00 5B 81 EB 63 00 - C1 EB 04 8C C8 01 C3 8E  č..[ëc. Áë.ŚČ.ĂŽ
0070 DB 53 6A 75 CB F6 06 02 - 00 04 74 0F 31 C0 8E C0  ŰSjuËö.. ..t1ŔŽŔ
0080 BF FC 05 66 B8 44 55 43 - 45 66 AB 68 00 20 17 BC  żü.f¸DUC Ef«h. Ľ
0090 00 90 31 C9 51 BA 80 00 - 52 B4 08 F9 CD 13 5A 58  .1ÉQş€. R´.ůÍZX
00A0 16 07 72 17 80 E1 3F F9 - 74 11 91 B4 02 89 C5 31  .r€á?ů t‘´.‰Ĺ1
00B0 DB 41 52 F9 CD 13 5A 72 - 02 F6 DC 0E 1F 9C 31 F6  ŰARůÍZr .öÜś1ö
00C0 31 FF B9 DF 00 FC F3 A5 - BB FC 1F 66 B8 47 52 55  1˙ąß.üóĄ »üf¸GRU
00D0 AA 66 39 07 75 03 E8 EE - 1A EA DE 00 00 20 16 1F  Şf9.u.čî ęŢ.. 
00E0 66 39 07 74 31 66 60 A1 - 18 00 83 F8 3F 77 20 3C  f9.t1f`ˇ .ř?w <
00F0 10 72 1C 48 BF 03 00 B4 - 02 99 BB 00 02 B9 02 00  rHż..´ .™»..ą..
0100 60 CD 13 61 73 09 60 31 - C0 CD 13 61 4F 75 E8 66  `Ías.`1 ŔÍaOučf
0110 61 66 39 07 75 56 9D 72 - 3E 0E 1F AD 88 E6 AD 89  af9.uVťr >­ć­‰
0120 C1 24 3F 74 1F 29 E8 48 - F6 D8 BF 03 00 B4 02 68  Á$?t)čH öŘż..´.h
0130 00 0D 07 31 DB 60 CD 13 - 61 73 0A 60 31 C0 CD 13  ...1Ű`Í as.`1ŔÍ
0140 61 4F 75 E9 F9 E8 30 11 - 0F 87 94 1A 83 C6 0C 81  aOuéůč0 ‡”Ć.
0150 FE FE 01 72 C4 77 15 BE - B2 31 B4 08 99 52 CD 13  ţţ.rÄwľ ˛1´.™RÍ
0160 58 72 09 99 91 24 3F 74 - 03 41 EB BE BE 8F 01 E8  Xr.™‘$?t .AëľľŹ.č
0170 16 00 EB FE FA B8 00 20 - 8E D0 BC DC 8F FB 66 61  .ëţú¸.  ŽĐĽÜŹűfa
0180 07 1F EB C8 B4 0E CD 10 - 2E AC 3C 00 75 F6 C3 0D  .ëČ´Í .¬<.uöĂ.
0190 0A 4D 69 73 73 69 6E 67 - 20 4D 42 52 2D 68 65 6C  .Missing  MBR-hel
01A0 70 65 72 2E 00 00 00 00 - 00 00 00 00 00 00 00 00  per..... ........
01B0 00 00 00 00 00 00 00 00 - 5B 44 35 0E 00 00 00 FE  ........ [D5...ţ
01C0 FF FF 07 FE FF FF 00 50 - 1E 02 00 C0 19 38 80 20  ˙˙.ţ˙˙.P ..Ŕ8€ 
01D0 21 00 0C FE FF FF 00 08 - 00 00 00 48 1E 02 00 00  !..ţ˙˙.. ...H...
01E0 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00  ........ ........
01F0 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 55 AA  ........ ......UŞ

[Sector 1]  0MB
0200 33 C0 8E D0 BC 00 7C FB - 50 07 50 1F FC BE 1B 7C  3ŔŽĐĽ.|ű P.Püľ|
0210 BF 1B 06 50 57 B9 E5 01 - F3 A4 CB BD BE 07 B1 04  ż.PWąĺ. ó¤Ë˝ľ.±.
0220 38 6E 00 7C 09 75 13 83 - C5 10 E2 F4 CD 18 8B F5  8n.|.u ĹâôÍ‹ő
0230 83 C6 10 49 74 19 38 2C - 74 F6 A0 B5 07 B4 07 8B  ĆIt8, tö µ.´.‹
0240 F0 AC 3C 00 74 FC BB 07 - 00 B4 0E CD 10 EB F2 88  đ¬<.tü». .´Íëň
0250 4E 10 E8 46 00 73 2A FE - 46 10 80 7E 04 0B 74 0B  NčF.s*ţ F€~..t.
0260 80 7E 04 0C 74 05 A0 B6 - 07 75 D2 80 46 02 06 83  €~..t. ¶ .uŇ€F..
0270 46 08 06 83 56 0A 00 E8 - 21 00 73 05 A0 B6 07 EB  F..V..č !.s. ¶.ë
0280 BC 81 3E FE 7D 55 AA 74 - 0B 80 7E 10 00 74 C8 A0  Ľ>ţ}UŞt .€~.tČ 
0290 B7 07 EB A9 8B FC 1E 57 - 8B F5 CB BF 05 00 8A 56  ·.ë©‹üW ‹őËż..ŠV
02A0 00 B4 08 CD 13 72 23 8A - C1 24 3F 98 8A DE 8A FC  .´.Ír#Š Á$?ŠŢŠü
02B0 43 F7 E3 8B D1 86 D6 B1 - 06 D2 EE 42 F7 E2 39 56  C÷ă‹Ń†Ö± .ŇîB÷â9V
02C0 0A 77 23 72 05 39 46 08 - 73 1C B8 01 02 BB 00 7C  .w#r.9F. s¸..».|
02D0 8B 4E 02 8B 56 00 CD 13 - 73 51 4F 74 4E 32 E4 8A  ‹N.‹V.Í sQOtN2äŠ
02E0 56 00 CD 13 EB E4 8A 56 - 00 60 BB AA 55 B4 41 CD  V.ÍëäŠV .`»ŞU´AÍ
02F0 13 72 36 81 FB 55 AA 75 - 30 F6 C1 01 74 2B 61 60  r6űUŞu 0öÁ.t+a`
0300 6A 00 6A 00 FF 76 0A FF - 76 08 6A 00 68 00 7C 6A  j.j.˙v.˙ v.j.h.|j
0310 01 6A 10 B4 42 8B F4 CD - 13 61 61 73 0E 4F 74 0B  .j´B‹ôÍ aasOt.
0320 32 E4 8A 56 00 CD 13 EB - D6 61 F9 C3 49 6E 76 61  2äŠV.Íë ÖaůĂInva
0330 6C 69 64 20 70 61 72 74 - 69 74 69 6F 6E 20 74 61  lid part ition ta
0340 62 6C 65 00 45 72 72 6F - 72 20 6C 6F 61 64 69 6E  ble.Erro r loadin
0350 67 20 6F 70 65 72 61 74 - 69 6E 67 20 73 79 73 74  g operat ing syst
0360 65 6D 00 4D 69 73 73 69 - 6E 67 20 6F 70 65 72 61  em.Missi ng opera
0370 74 69 6E 67 20 73 79 73 - 74 65 6D 00 00 00 00 00  ting sys tem.....
0380 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00  ........ ........
0390 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00  ........ ........
03A0 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00  ........ ........
03B0 00 00 00 00 00 2C 44 63 - 5B 44 35 0E 00 00 00 FE  .....,Dc [D5...ţ
03C0 FF FF 07 FE FF FF 00 50 - 1E 02 00 C0 19 38 80 20  ˙˙.ţ˙˙.P ..Ŕ8€ 
03D0 21 00 0C FE FF FF 00 08 - 00 00 00 48 1E 02 00 00  !..ţ˙˙.. ...H...
03E0 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00  ........ ........
03F0 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 55 AA  ........ ......UŞ

[Sector 2]  0MB
0200 EB 58 90 47 52 4C 44 52 - 20 20 20 00 02 01 01 00  ëXGRLDR    .....
0210 02 00 00 00 00 F8 00 00 - 12 00 02 00 00 00 00 00  .....ř.. .......
0220 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00  ........ ........
0230 00 00 06 00 00 00 00 00 - 00 00 00 00 00 00 00 00  ........ ........
0240 00 00 29 63 AF C4 0A 4E - 4F 20 4E 41 4D 45 20 20  ..)cŻÄ.N O NAME  
0250 20 20 46 41 54 33 32 20 - 20 20 FA FC B6 FF 80 FE    FAT32    úü¶˙€ţ
0260 FF 75 02 B2 00 31 C0 8E - D8 BD 00 7C 8E C0 8E D0  ˙u.˛.1ŔŽ Ř˝.|ŽŔŽĐ
0270 8D 66 E0 FB 89 56 40 B4 - 41 BB AA 55 CD 13 72 10  Ťfŕű‰V@´ A»ŞUÍr
0280 81 FB 55 AA 75 0A F6 C1 - 01 74 05 C6 06 8F 7D 42  űUŞu.öÁ .t.Ć.Ź}B
0290 66 31 C0 66 89 46 44 8B - 46 0E 66 03 46 1C 66 89  f1Ŕf‰FD‹ Ff.Ff‰
02A0 46 48 66 89 46 4C 66 8B - 46 10 66 F7 66 24 66 01  FHf‰FLf‹ Ff÷f$f.
02B0 46 4C 66 8B 46 2C 66 50 - E8 8A 00 BE B8 7D 0F 82  FLf‹F,fP čŠ.ľ¸}‚
02C0 2F 01 C4 9E E8 01 E8 98 - 00 31 FF B9 0B 00 BE BB  /.Äžč.č .1˙ą..ľ»
02D0 7D F3 A6 74 15 83 C7 20 - 83 E7 E0 3B 7E 0B 75 EB  }ó¦tÇ  çŕ;~.uë
02E0 4A 75 DF 66 58 E8 29 00 - EB CC 26 FF 75 09 26 FF  JußfXč). ëĚ&˙u.&˙
02F0 75 0F 66 58 31 DB 66 50 - E8 4A 00 73 07 8B 56 40  ufX1ŰfP čJ.s.‹V@
0300 FF AE E8 01 E8 5A 00 4A - 75 FA 66 58 E8 02 00 EB  ˙®č.čZ.J uúfXč..ë
0310 E5 06 53 66 C1 E0 02 66 - 0F B7 5E 0B 66 F7 F3 66  ĺ.SfÁŕ.f ·^.f÷óf
0320 03 46 48 BB 60 00 8E C3 - 31 DB 66 3B 46 44 74 07  .FH»`.ŽĂ 1Űf;FDt.
0330 66 89 46 44 E8 2A 00 26 - 67 80 62 03 0F 26 67 66  f‰FDč*.& g€b.&gf
0340 8B 02 5B 07 C3 66 3D F8 - FF FF 0F F5 72 12 66 48  ‹.[.Ăf=ř ˙˙őrfH
0350 66 48 66 0F B6 56 0D 52 - 66 F7 E2 5A 66 03 46 4C  fHf¶V.R f÷âZf.FL
0360 C3 66 60 66 31 D2 66 52 - 66 50 06 53 6A 01 6A 10  Ăf`f1ŇfR fP.Sj.j
0370 66 31 C9 66 FF 76 18 59 - 66 F7 F1 42 59 52 31 D2  f1Éf˙vY f÷ńBYR1Ň
0380 66 F7 F1 86 D6 59 86 C5 - C0 E4 06 08 E1 B8 01 02  f÷ń†ÖY†Ĺ Ŕä..á¸..
0390 89 E6 8A 56 40 CD 13 61 - 66 61 72 52 66 40 03 5E  ‰ćŠV@Ía farRf@.^
03A0 0B 73 09 52 8C C2 80 C6 - 10 8E C2 5A C3 64 69 73  .s.RŚÂ€Ć ŽÂZĂdis
03B0 6B 20 65 72 72 6F 72 00 - 4E 6F 20 47 52 4C 44 52  k error. No GRLDR
03C0 20 20 20 20 20 20 00 00 - 00 00 00 00 00 00 00 00        .. ........
03D0 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00  ........ ........
03E0 00 00 00 00 00 00 00 00 - 00 00 00 20 BB 59 BE AD  ........ ... »Yľ­
03F0 7D AC B4 0E CD 10 3C 00 - 75 F7 EB FE 00 00 55 AA  }¬´Í<. u÷ëţ..UŞ

========= END OF SECTOR DATA ================

 

3. Sorry if I wasn't more explicite: I don't use that menu entry to load an Iso, I load an INSTALLED Linux from a partition of my internal HDD.
 

Use latest RMPrepUSB - Bootloaders tab - Install Std MBR - does not destroy paritition table - just replaces MBR boot code. You can swap between grub4dos and standard MBR easily using this and the 'Install grub4dos' button.

I will try that if restoring from sector 2 will not solve my problem.

 

 

[steve6375]

Well the backup is there.

I would restore it using either RMPrepUSB or Disk Doctor (inside RMPrepUSB - hit Ctrl D). Or you can use a disk editor like WinHex (but make sure you select Physical Disk!).

 

To do it in RMPrepUSB:

1. Select USB drive in drive list

2. Drive-> File - S0.bin, start=0, Length=512, Filestart=0    (saves MBR)

    Drive-> File - S1.bin, start=1, Length=512, Filestart=0     (saves old MBR)

 

You can check the contents of each of these using File Info button.

 

3. File->Drive, S1.bin, file start=0, usb start=0, length=0   (writes LBA1 to LBA0)

[DavidB]

A small problem: S0.bin and S1.Bin have the same start, Length and FileStart. Shouldn't S1 start at 512 bytes, for example? Just saying...

Edited by DavidB, 14 February 2013 - 02:32 PM.

[steve6375]

Doh! Sorry, yes 1 start for s1.bin!

[DavidB]

I did that but now when I try to boot it says that Windows 7 boot message:

Bootmgr is missing

Press any key to restart

[steve6375]

That means your PBR is set to look for bootmgr.

Use Drive Info - P1 to view the PBR.  Do you see BOOTMGR in first sector near the bottom?

Did you want to put grub4dos in the PBR? If so, run RMPrepUSB - Install grub4dos and say No to put code in PBR...

[DavidB]

Found the problem.
The flash drive has 2 partitions, one Fat32 and one NTFS. I use the Fat32 to boot.
But the Fat32 was created (chronologically) after the NTFS. So, even if the Fat32 is physically before the NTFS, is seen as the second partition.
So I had to manually run "grubinst.exe --verbose --pause --install-partition=1 (hd1)" instead of "grubinst.exe --verbose --pause --install-partition=0 (hd1)" which is used in RMPrepUSB by default.

Thank you very much for your help.

Best regards, David

[Wonko the Sane]

Found the problem.
The flash drive has 2 partitions, one Fat32 and one NTFS. I use the Fat32 to boot.
But the Fat32 was created (chronologically) after the NTFS. So, even if the Fat32 is physically before the NTFS, is seen as the second partition.
So I had to manually run "grubinst.exe --verbose --pause --install-partition=1 (hd1)" instead of "grubinst.exe --verbose --pause --install-partition=0 (hd1)" which is used in RMPrepUSB by default.

Thank you very much for your help.

Best regards, David

 

Well, just in case:

http://www.911cd.net...showtopic=24392

 

It is a good idea to have entries in partition table be in the same order as the partitions are on the device, to mantain "wider" compatibility.

 

Wonko

[steve6375]

FYI: RMPrepUSB will re-order the partitions into ascending order for you if you wish.

 

If you had set the FAT32 ptn as Active - it would have worked.

[DavidB]

Well, just in case:

http://www.911cd.net...showtopic=24392

 

It is a good idea to have entries in partition table be in the same order as the partitions are on the device, to mantain "wider" compatibility.

 

Wonko

 

 

Yes, it is.
Thank you for the link.

 

FYI: RMPrepUSB will re-order the partitions into ascending order for you if you wish.

 

If you had set the FAT32 ptn as Active - it would have worked.

 

 

Yes, you're right.
RMPrepUSB is a very good program. Is there a Linux version...?