BartPE, GRUB & a Logical partition, Can a logical partition be booted?? Options

[Ed_P]

I put BartPE on my notebook's E: partition, which is a Logical partition rather than a Primary. I then put GRUB Loader on C: but when I boot I can't get GRUB to boot BartPE on the E: drive.

I have a similar setup on my desktop but I realize that my desktop machine has BartPE on the Primary drive of my 2nd hd. In fact none of my bootable BartPE systems is on a Logical drive except for the one on my notebook. Is that why I can't boot it using GRUB?

[cdob]

You can't boot DOS or Windows from a logical partition.
Ntldr/setupldr.bin has to be on a primary partiton.

Yes, ntldr may load following files from a logical partition.
But ntldr or grub can't load BartPE that way.

Use a primary partition for BartPE.

[Ed_P]

Thanks cdob.

Well, supposedly according to this fascinating thread Windows can indeed be booted from a Logical partition. But it takes some work. So I think I will try the Primary approach.

A quick question, on the partition where I have BartPE loaded, it is not the 1st set of files in the partition. I have several image backups stored there 1st then BartPE. Could that be a problem booting or does it matter?

[cdob]

Thanks. Yes, that's the difficult: a valid boot sector at a logical partition.
You have to create a valid boot sector yourself.

I'm used to NTFS partitions. I've several BartPE images at second primary partiton.
All imgaes are loadable. Image order dosn't matter booting.

[Ed_P]

Update:

It WORKS!!!

I changed the two Logical partitions to Primary versions and I can now boot BartPE with GRUB. The only thing that's a little strange, but I can live with, GRUB references the 3rd partition, my E: drive, as (hd0,1) !! I would have thought it would be (hd0,2).

But at this point, it works!! and that's all I really care about, for now.

Thanks cdob.

[FM_81]

But however, it's possible to have BartPE on a logical drive, and to boot it with GRUB, and there is no NTLDR or any other XP-bootfile on an other drive or partition of this machine, as on this logical drive!
The link in Ed_P's third post in this topic gave the right idea...

Let's call the partition in this example (hd0,10) in GRUB-notation and it should have the letter G: under PE.
I've formated it with a PE-CD in NTFS, copied folders I386 and PROGRAMS, renamed I386 to miniNT, copied SETUPLDR.BIN, NTDETECT.COM, WINBOM.INI, BOOTFONT.BIN to the root of G:, renamed SETUPLDR.BIN to NTLDR.

Then lets have a look in the link above, chapter fixing the bootsector. Change the number of hidden sectors, like described there (THATS A VERY GREAT ARTICLE!).
That seems the only trick, to get it booting. You should have a tool like PTEDIT, or an equivalent and you should exactly know what you do, and you should have backups of your data!!!

Voila, thats all. If we assume, you have GRUB already installed (on an other partition or using GRLDR), add to your menu.lst:

CODE

title MiniNT
chainloader (hd0,10)+1

Numbers of partitions here are only an example, should be changed, how needed.
Could test this this only on one PC, and only with an 'normal' IDE-drive, so any additional info is welcome!

MfG FM_81

[Ed_P]

Hello FM_81.

On my bootable (Primary) partition I have NTLDR, NTDETECT.COM, bootsect.bin, WIN51C, WIN51C.SP2 and autorun.inf together with the MININT and Programs folders. I do not have the WINBOM.INI and BOOTFONT.BIN files that you mention. I initially had WINBOM.INI and TXTSETUP.SIF in the root but found that I could boot without them. I suspect you will find the same with your two files. I am reasonably certain I don't need the autorun.inf file either but I haven't tested that yet.

[FM_81]

@ Ed_P
That's possible!
But the important point in my previous post was, that it can exist (stand alone) on a logical drive and doesn't need bootfiles from other (primary) partitions. Means, it works only from the logical drive, and will be booted by GRUB!

MfG FM_81

[jaclaz]

Please note that GRLDR, besides "chainloading" a partition can also DIRECTLY chainload NTLDR (or SETUPLDR.BIN:

Directly boot NTLDR of WinNT/2K/XP and IO.SYS of Win9x/ME and
KERNEL.SYS of FreeDOS. Examples:

chainloader [--edx=0xPPDD](hd0,0)/ntldr
boot

chainloader [--edx=0xDD] (hd0,0)/io.sys
boot

chainloader [--ebx=0xDD] (hd0,0)/kernel.sys
boot

The hex DD specifies the boot drive number, and PP specifies
the boot partition number of NTLDR. If the boot drive is
floppy, PP should be the hex value ff.

This way, it should be possible to "bypass" the actual BOOTRECORD of the Logical Volume inside Extended Partition.

I haven't tried it, as I do not have a system configured as yours, but you can try:

chainloader (hd0,10)/ntldr

or

chainloader (hd0,10)/SETUPLDR.BIN

(remember that GRUB uses CaSe SeNsItIvE names)

On my GRUB based bootCD, I use (using GRLDR as no-emulation file)

chainloader /I386/SETUPLDR.BIN

and it works allright.

jaclaz

[Ed_P]

@jaclaz

Oh sure, NOW you tell me.

Not sure I understand though. Are you saying these two commands are the same?

chainloader [--edx=0x1000] (hd0,10)/ntldr


chainloader (hd0,10)/ntldr


I don't understand the --edx part.


@FM_81

I understood what you were saying, I was just trying to refine the process.

[FM_81]

@jaclaz
Yes, you're fully correct, and these (well known) methods works, because GRUB is such a great tool!

But the way with the patched bootsector of logical drive works with other loaders too, I've tested LILO and GUJIN, and maybe a lot of other BM's will do so...

MfG FM_81

[jaclaz]

I don't understand the --edx part.

Neither do I, all I did was trying, as said, on CD with GRLDR as no-emulation image:

chainloader /I386/SETUPLDR.BIN

and it worked (GRUB defaults to (cd) when booted this way).

I don't see why it should not work the other way with the (hd0,x) sintax.

@FM_81

Yep, but all in all, though I am a "reknown" MBR/Bootrecord "hacker", I prefer not to mess to much with them, expecially if the PC goes in other hands.
Running some versions of Partition Magic on a such modified hard disk, for example "could" (and will) give errors.

jaclaz

[Ed_P]

The only hit I was able to find for the use of the --edx option is here:

ibm.ibmpc.thinkpad

CODE

title  W2K-vfat (USB-SDA1) executable, marked hidden from other WinJunk
# rootnoverify (hd0,0)                         does not work
# chainloader +1                               does not work
   chainloader --edx=0x0080 (hd0,0)/ntldr

And I still don't understand it's purpose.

Where did you find that quote for it's use jaclaz?

[FM_81]

@ jaclaz

Running some versions of Partition Magic on a such modified hard disk, for example "could" (and will) give errors.

Yes, and this could also happen, if you use other and different tools on the same harddisk.

And who's using such tools, which make changes deep in the harddisk-structure, should always know, what he does, or not wondering after all ...

MfG FM_81

[jaclaz]

The only hit I was able to find for the use of the --edx option is here:

ibm.ibmpc.thinkpad

CODE

title  W2K-vfat (USB-SDA1) executable, marked hidden from other WinJunk
# rootnoverify (hd0,0)                         does not work
# chainloader +1                               does not work
   chainloader --edx=0x0080 (hd0,0)/ntldr

And I still don't understand it's purpose.

Where did you find that quote for it's use jaclaz?

On the GRUB4DOS help file, it is called README.txt and is inside the downloaded file:
http://sarovar.org/download.php/989/grub_f...s-0.4.2pre4.zip
In this latest release, the info has been updated as follows:

Update 9: Directly boot NTLDR of WinNT/2K/XP and IO.SYS of Win9x/ME and
KERNEL.SYS of FreeDOS. Examples:

chainloader --edx=0xPPYY (hd0,0)/ntldr
boot

chainloader --edx=0xYY (hd0,0)/io.sys
boot

chainloader --ebx=0xYY (hd0,0)/kernel.sys
boot

Hex YY specifies the boot drive number, and hex PP specifies
the boot partition number of NTLDR. If the boot drive is
floppy, PP should be the hex value ff, i.e., decimal 255.

For KERNEL.SYS of FreeDOS, the --edx won't work,
use --ebx please.

The option --edx ( --ebx ) can be omitted if the file is in
its normal place. But in some cases, those options are needed.

If, e.g., the ntldr file is in an ext2 partition called
(hd2,8) while you want it to think of the Windows partition
(hd0,7) as the boot partition, then --edx is required:

chainloader --edx=0x0780 (hd2,8)/ntldr

For DOS kernels(i.e., IO.SYS and KERNEL.SYS), the boot
partition number is meaningless, so you only need to specify
the correct boot drive number YY(but specifying the boot
partition number is harmless).

Tip: CMLDR (the ComMand LoaDeR, which is used to load the
Windows Fault Recovery Console) can be chainloaded as well
as NTLDR.

Bean has successfully decompressed and booted IO.SYS of WinME.
Thanks for the great job!

jaclaz