Hello,
I'm novice to Grub4dos and need some help loading truecrypt mbr from Grub4dos
In short, the goal is to test a setup with Grub4dos installed on USB than chainloads a truecrypt mbr put on the same usb (extracted from encrypted Win7 system hdd)
The test setup:
1. Installed Win7 evaluation on VMware virtual HDD and encrypted it (test both normal truecrypt system encryption and hidden OS truecrypt system encryption)
2. Extracted grub4dos-0.4.6a-2014-01-17 on the encrypted HDD
3. Installed Grub4dos mbr on an USB stick using grubinst-1.1-bin-w32-2008-01-01 (couldn't find newer installer)
4. Copied grldr to USB
5. Created a MENU.LST file
6. Extracted the mbr of the encrypted disk and copied it to USB (let's call the file t.mbr)*.
7. I boot the VMware from plop linux iso where I select to boot from usb (as booting from usb is not supported in the VMware BIOS)
*I have found in this and several other forums various methods for this mbr extraction, e.g.:
1/ sudo dd if=/dev/sda of=/mnt/boot/truecrypt.mbr count=1 bs=512 (e.g. from linux live CD)
2/ Using Grub4DOS Toolbox for Windows-0.23.exe (file saved as .img or as .mbr)
3/ Using HDHACKER (file saved as .dat)
4/ Using Bootice (file saved as .bin)
I'm not an mbr expert, but afaik, I need only 1st 512 bytes, so I have extracted the 1st sector using all of the apps/commands mentioned.
Based on various threads here and on other forums I have tested both booting from iso image and from any of the extracted mbr files, all of them copied in the root folder of the USB.
I've seen several threads about successful setups with the truecrypt mbr extracted, e.g.:
http://reboot.pro/to...ypt +bootloader
or
http://reboot.pro/to...t-record/page-2
Here are my efforts with two MENU.LST files to boot from such mbr file on the USB:
Option 1:
timeout 5
title TESTSYS
chainloader (hd0,0)/t.mbr
Option 2:
timeout 5
title TESTSYS1
find --set-root /t.mbr
chainloader /t.mbr
rootnoverify (hd0,0)
In both cases, the result is:
1/ a message "Loader damaged! Use Rescue disk: Repair Options > Restore TryeCrypt bootloader", when .mbr or .img extension file is used.
2/ a message "GRUB" with blinking cursor, when .bin extension file is used. An no option to boot.
3/ a message "Error 13: Invalid or unsupported executable format", when .dat extension or no extension file is used.
When using some map and hook commands, there is no problem booting from the iso (e.g. any linux live CD) and when it is the truecrypt rescue disk - no
problem to boot into the encrypted system.
Here is the MENU.LST:
timeout 5
title TEST
find --set-root /test.iso
map /test.iso (hd32)
map (hd0) (hd1)
map (hd1) (hd0)
map --hook
root (hd32)
chainloader (hd32)
However, any replace of an test.iso file with truecrypt mbr extract (whatever extract method and extract file extension used), results in a message:
"Error 25: Disk read error"
At the same time, the enxrypted VM boots with the truecrypt mbr originally installed on the virtual HDD.
Obviously, I'm doing something wrong - either the mbr extract step or the menu.lst file in all options tested.
Any suggestions how to fix this would be highly appreciated.