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#1 2012-11-03 21:24:59

rakiner
New member
Registered: 2012-06-22
Posts: 7

Grub2 and UEFI

Hi,

I have been trying the new grub-2.00-r2 package and booting in UEFI mode.  It works rather well, especially if you are booting linux kernels.  boot-update should handle everything just fine if you just want to boot linux as usual, but there are a few caveats that I encountered, and it would be nice if they were addressed.

When booting in UEFI mode, I found it was necessary to enable and use the grub2 gfxterm.  Failure to do this results in a 'blind' boot for the kernel, and you will not see any kernel text or tty text until X loads or the DRM driver loads.  Details on how to enable this are at https://wiki.archlinux.org/index.php/GR … ound_Error

It would be nice if there were an option to add the insmods and font loading/checking to boot-update, as it stands, I have to add these to the top of my grub.cfg manually.  If I am mistaken and there IS a way, please correct me.

Another issue I encountered was booting Windows 7.  I realized that you cannot really boot a mbr/bios based windows install from a uefi grub boot loader so I converted windows over to uefi, but the boot menu entry requires a little work.  I used the windows UEFI boot loading code from http://wiki.gentoo.org/wiki/GRUB2#MSDOS.2FWindows with a little adjustment:

menuentry "Windows 7" {                                                                                                              
  insmod part_gpt                                                                                                                    
  insmod search_fs_uuid                                                                                                              
  insmod chain                                                                                                                       
  search --fs-uuid --no-floppy --set 4FA1-F4B2                                                                                       
  chainloader ($root)/EFI/MICROSOFT/BOOT/bootmgfw.efi                                                                                
}

Basically you need to set the root partition to the uuid of the efi boot partition like boot-update mostly already does, and then chain load the bootmgfw.efi file from the specific directory.  It would be nice if there were an additional boot.conf target to load up this efi file instead of just chain loading the partition... perhaps "type win7-uefi" instead of "type win7"?

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#2 2013-06-16 13:01:07

alexpj
Member
From: England
Registered: 2012-08-18
Posts: 49

Re: Grub2 and UEFI

rakiner,

Did you ever find out where the proper place to add insmod lines in the grub.cfg is?
http://wiki.gentoo.org/wiki/GRUB2#Booti … al_Volumes suggests that there should be a /etc/default/grub to add the list of modules into but I don't have one - does anyone else?

TIA.

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