Arch Linux

johannesg00

Member

Registered: 2010-11-30

Posts: 74

Boot Windows 8.1 in MBR mode from UEFI GRUB

Hi,

i installed Windows 8.1 in BIOS/MBR mode to my second hardisk /dev/sdb.
On my first disk /dev/sda is Archlinux with GRUB 2.0 in UEFI mode.

Is it possible to boot Windows 8.1 from the UEFI GRUB?

The description in the wiki is only for MBR systems...
https://wiki.archlinux.org/index.php/Gr … S-MBR_mode

Thank you

WonderWoofy

Member

From: Los Gatos, CA

Registered: 2012-05-19

Posts: 8,414

Re: Boot Windows 8.1 in MBR mode from UEFI GRUB

No. Mixing and matching bios and uefi will work fine, but you cannot jump from one to the other easily like that outside of the firmware boot manager.  Depending on the vendor's firmware implementation, even that might not be straight forward.

srs5694

Member

From: Woonsocket, RI

Registered: 2012-11-06

Posts: 719

Website

Re: Boot Windows 8.1 in MBR mode from UEFI GRUB

Actually, rEFInd can switch from EFI-mode to BIOS-mode booting; however, on PCs it's usually restricted to booting the BIOS-mode boot loader in the MBR of the first disk. Thus, you might need to physically swap your disk cables to get it to work. You'll also need to uncomment the "scanfor" line in refind.conf and add "hdbios" to its boot options list.

Oh, you also need a version of rEFInd compiled with Tianocore, not GNU-EFI. My own main binaries are so compiled (I'm rEFInd's author), and I believe that Arch's are, too, but some others are built with GNU-EFI.

Last edited by srs5694 (2014-03-15 20:10:29)