GPT UEFI Partitioning Query

FastTurtle · Posted: Tue Jul 15, 2014 6:27 pm Post subject: GPT UEFI Partitioning Query

I'm attempting to use an EFI-stub kernel on a GPT (gparted) partitioned/formated disk yet Grub 2 does not see the /boot partition (linux-ext2). In fact grub2 gave me an error about not finding a partition to install on so I'm not sure what in heck went wrong - had left 3M of space free before the /boot partition for Grub2 to install it's files in.

What I'm thinking was the problem was that the /boot was labeled as Linux (8300) instead of the needed ef00 for an ESP so any information would be appreciated.

Another thing is that I'm seeing lots of efi_stub kernels that use one of the efi packages such as refind in place of grub. Links appreciated on how to configure such to show now only various gentoo but a Win7-64 kernel (Yes! it's efi aware as you can install on a Mac).

khayyam · Posted: Tue Jul 15, 2014 7:37 pm Post subject: Re: GPT UEFI Partitioning Query

FastTurtle · Posted: Tue Jul 15, 2014 9:53 pm Post subject:

so refind is a replacement for lilo/grub (grub2 :twisted:

)

On the ESP partition, don't know if the MS boot loader needs it since I'm not using that option as yet (have to test with the CD as my flash drive installer doesn't have the needed efi kernel)

DONAHUE · Posted: Wed Jul 16, 2014 12:08 am Post subject:

vaxbrat · l33t Joined: 05 Oct 2005 Posts: 731 Location: DC Burbs

Grub2 wants an EF02 partition number. I think it only really needs 2mb as a bare minimum. Note that this is before /boot which you can keep as is. It ends up parking additional grub2 code in there which would be too big for the classic MBR boot code scheme. I run the following scheme on a MythTV box where I have the system root setup as a btrfs subvolume.

srs5694

khayyam

srs5694

ct85711 · Veteran Joined: 27 Sep 2005 Posts: 1791

I did manage to install windows 7 on UEFI; and one thing I will mention for windows wise is that it doe require a esp drive (the partition only needs to be on one of the drive, windows will accept having the ESP partition on a different drive than what windows is installed on. One issue I encountered when installing windows 7, is that by default (at least for me) it does not install in UEFI mode, I had to use a usb boot drive to boot the windows installer in UEFI. Also Windows 7 will also make a second partition, a Microsoft reserved (mine was 128MB), with the Microsoft basic data being the normal partition with the windows files and stuff. I am using grub2 by it's self as my bootmanager (also supports dual booting into windows) without refind used at all. Included below is my partition setup.

FastTurtle · Posted: Mon Aug 11, 2014 3:41 pm Post subject:

Donahue:

My system is a full UEFI boot with Win7 as primary, Gentoo is secondary.
Reading the refind install docs, it appears I'll have to use the manual method but forgo doing it from windows other then extracting and removing things not needed such as the ia32.efi.

Question in regards to kernel naming/config:

is it mandantory to include the efi-stub feature in the kernel to boot on an efi system?

Khayyam:

for a straight boot of an efi-stub kernel (supposedly supported by the standard), I can use foo_x64.efi for the efivars/efibootmgr to set things correctly?

Hadn't thought about the diff between a loader and manager but can see it now that it's pointed out. On refind, all I'd need to do is copy the /refind directory to the ESP? The manual install doc isn't very clear on this point and would I use the efibootmgr to establish refind as the main boot system? as it looks as though the manual states using bcdedit (windows tool) to change things but of course MS has to protect the user from themself even if they can mount the volume. <rant> if I didn't need windows (onenote mainly) I'd simply blow it off the system and use Gentoo.</rant> Nice thing about full system backups, it's possible to do that and say to hades with ye!

ct85711 · Veteran Joined: 27 Sep 2005 Posts: 1791

I can't really say if the efi stub is required in the kernel to boot an efi system, I myself, have it enabled even though I don't use the efi stub to boot my system. I still go through grub2 to boot my efi system perfectly fine. I would mention, you may want to check in your bios; as some bios has an option built in to switch to the default boot system. My MB/bios has that option; so after I installed windows (of course windows has to set it's self as default); I just used my bios to change it back and it worked perfectly fine.

From my understanding (and partly of when I tested it out), when you install refind, it'll automaticaly set it's self up as the main boot system, assuming you use the install script. Otherwise if you do the manualy installation you will have to use efibootmgr to set it up (along with coping refind to the esp). (Again, assuming you are using an ESP partition; which windows requires in addition to the extra partion it requires, not counting the normal data partition. So in short Windows in efi mode, needs 3 partitions total.)

DONAHUE · Posted: Mon Aug 11, 2014 5:14 pm Post subject:

efi-stub is a bootloader, if you use another bootloader you don't need it
the worst case uefi board I worked on refused to honor efibootmgr (would only allow one uefi partition, to boot windows that had to be windows, the windows ESP would only honor bcdedit) thus the wiki was written to use bcdedit to implement refind. The file copying and editing of placing rEFInd on the ESP can be done in linux.
The rEFInd with efistub combination is my preference as there is no extra maintenance when a new kernel is compiled.
_________________
Defund the FCC.

FastTurtle · Posted: Mon Aug 11, 2014 6:18 pm Post subject:

ct85711: the ESP partition is actually defined in the UEFI Specs and MS got their way by requiring it to use fat as the format.

Well I've decided to nuke windows from orbit - Hell I'm gonna Death Star it - and do a clean Gentoo install. It'll be the only thing on the system.

FastTurtle · Posted: Fri Aug 15, 2014 3:51 am Post subject:

Got it working but still not fully stable.

On the refind script, if you're trying to use it from a SysRescue cd, the efibootmgr stage fails for some reason. If you use the sysresc cd to boot the kernel, efibootmgr and such all work properly - still haven't figured that out. Have finished restoring Win7 and all the blasted updates with everything but it's drive disconnected. When the others were connected the first thing windows wanted to do was format them while having no working USB (xhci/usb3 w/o driver installed). Murphy has really worked overtime the last few days but I've managed to keep him at bay (knock on wood) and should be able to get refind installed as the boot loader this weekend. Have to finish restoring files from backup so I'm at least operational.

FastTurtle · Posted: Sat Aug 16, 2014 10:08 pm Post subject:

It Lives - Somewhat. Gentoo now boots and is partly usable. Had to edit the refind_linux.conf entries that used the UUID for rootfs instead of the PARTUUID. Note that I'm using the kernel command line to boot and will be testing the refind_.conf to ensure it's now working.

A problem I suspect is related is that Windows wont boot using refind - suspect it's the UUID being used instead of the PARTUUID - could be wrong.

I'm using the refind-bin-0.8.3 file and installed using the install.sh script. Worked like a charm once I though to boot the Gentoo system using the System Rescue disk so I'm in full UEFI mode for both Windows and Gentoo.

Minor issues to address is the clock skew being detected - will add an ntp-client to fix that problem.