[SOLVED] UEFI Dual Boot Windows

illtech · 2011-09-21 09:34:08

Heya,

Been stuck on this one for a couple of days and havent been able to work it out, if anyone has any information or could point me the right direction it would be much appreciated.

I have a Thinkpad X220 which I previously had Win7 and Arch Linux installed in dual boot (BIOS). Recently I added in a mSATA SSD and thought I would give this whole UEFI thing a shot.

Formatted the new SSD in the gpt format, got arch linux installed in UEFI mode with a bit of trickery (had to copy files to a fat32 usb disk, copy over the efi/* files and then manually edit the grub boot loader line when it booted off the usb - I think I had to add (hd2,1) or something similar.

Using the infomation from the arch/grub2 wiki I managed to get the bootloader installed, and now my PC boots Arch Linux from the UEFI/Grub2 menu fine. Problem is that my Windows 7 installation will no longer boot.

Looking at my partition table, I dont think my [preinstalled] Windows 7 installation came with a EFI boot partition. So uncommenting the appropriate lines in the /boot/efi/efi/grub/grub.cfg file doesn't work.

I think I also managled the original MBR on the original HDD (tried to get grub2-efi to install), so now booting in BIOS mode to this partition only throws some grub error.

I mounted my Windows 7 partition and tried to copy of the files in the Windows/Boot/EFI/ to /boot/efi/efi/microsoft/boot/ and tried to boot using the following in grub.cfg:

 menuentry "Windows" {
    insmod part_gpt
    insmod ntfs
    search --file --no-floppy --set=root /efi/microsoft/boot/bootmgfw.efi
    chainloader (${root})/efi/microsoft/boot/bootmgfw.efi
}

That didn't really do much either (GRUB2 menu just cycles).

I then tried to add the Win7Partition/BCD file to the same /boot/efi/efi/microsoft/boot folder and tried to boot using the same settings above - this just leaves me at a blank/black screen, with the only option to poweroff the laptop using the power button (even caps lock is unresponsive).

Anyone have any ideas on how I could get Win7 to boot again?

Last edited by illtech (2011-09-23 13:06:47)

skodabenz · 2011-09-23 08:58:15

illtech wrote:

Looking at my partition table, I dont think my [preinstalled] Windows 7 installation came with a EFI boot partition. So uncommenting the appropriate lines in the /boot/efi/efi/grub/grub.cfg file doesn't work.

AFAIK none of the OEM Windows installs come configured to boot in UEFI-GPT setup.

I think I also managled the original MBR on the original HDD (tried to get grub2-efi to install), so now booting in BIOS mode to this partition only throws some grub error.

grub_efi_x86_64-install does not touch the MBR of the HDD at all. You must have confused grub2-bios and grub2-uefi while trying to install grub2-uefi.

insmod ntfs

It should be

insmod fat

That didn't really do much either (GRUB2 menu just cycles).
I then tried to add the Win7Partition/BCD file to the same /boot/efi/efi/microsoft/boot folder and tried to boot using the same settings above - this just leaves me at a blank/black screen, with the only option to poweroff the laptop using the power button (even caps lock is unresponsive).

Win7Partition/BCD contains info to boot Windows in BIOS-MBR setup only and will not work in UEFI-GPT mode. You need to generate a new BCD using bcdboot as described at https://gitorious.org/tianocore_uefi_du … +Partition .

Last edited by skodabenz (2011-09-23 14:01:00)

illtech · 2011-09-23 13:05:44

You my friend are a genius

Managed to scrounge a Win7 x64 disc off a friend to access the repair console.

The bcdboot command combined with the "insmod fat" change, and now I am able to boot in to windows to play some StarCraft II (think its the only reason Windows is still installed on this machine).

To anyone else that might run in to this issue, I found that the bcdboot tool put another entry to the UEFI loader. This meant that I can choose to load Windows 7 directly by selecting the boot device using F12 on bootup (don't have to use grub to chainload if you don't want to).

Cheers mate,

nehaljwani · 2012-10-09 15:20:26

You don't necessarily need to dual boot Windows and Linux on UEFI. Follow the guide http://www.youtube.com/watch?v=PEou2dIcMSE to convert your UEFI to MBR-BIOS without loss of data.

Inxsible · 2012-10-09 20:28:37

nehaljwani, please do not necro-bump threads. Especially solved ones. Closing.

Arch Linux

#1 2011-09-21 09:34:08

[SOLVED] UEFI Dual Boot Windows

#2 2011-09-23 08:58:15

Re: [SOLVED] UEFI Dual Boot Windows

#3 2011-09-23 13:05:44

Re: [SOLVED] UEFI Dual Boot Windows

#4 2012-10-09 15:20:26

Re: [SOLVED] UEFI Dual Boot Windows

#5 2012-10-09 20:28:37

Re: [SOLVED] UEFI Dual Boot Windows

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