[External] Re: GRUB EFI blues - Debian 9/FAI 5.3.6

[Bob Apodaca]

Honeywell Internal









From: linux-fai [mailto:linux-fai-bounces at uni-koeln.de] On Behalf Of Andreas Heinlein
Sent: Wednesday, April 18, 2018 3:22 AM
To: linux-fai at uni-koeln.de
Subject: [External] Re: GRUB EFI blues - Debian 9/FAI 5.3.6



Am 18.04.2018 um 10:14 schrieb tt-fai at kky.ttu.ee<mailto:tt-fai at kky.ttu.ee>:

   I can second to that. I installed a SuperMicro X10SLM-F based server last month and did not find any option in the BIOS to PXE-boot FAI into UEFI mode. Ended up using disklabel:gpt-bios and GRUB_PC. I did not try to boot off an USB stick, so it is worth investigating if an option exists for booting that in UEFI mode.



   From my experiments I was left with the impression that it is not easy (or even possible) to “cross-install” UEFI-boot-capable disk if the system was booted into legacy (BIOS) mode. If someone has found a way to do it, I would also appreciate suggestions.



   Regards,

   Toomas



   From: linux-fai <linux-fai-bounces at uni-koeln.de><mailto:linux-fai-bounces at uni-koeln.de> On Behalf Of Andreas Heinlein
   Sent: Wednesday, April 18, 2018 9:56 AM
   To: linux-fai at uni-koeln.de<mailto:linux-fai at uni-koeln.de>
   Subject: Re: GRUB EFI blues - Debian 9/FAI 5.3.6



   Am 18.04.2018 um 00:28 schrieb Bob Apodaca:

      I think the first issue is FAI is setting the GRUB_PC class instead of the GRUB_EFI class and I'm not sure why.

   I am pretty sure this depends on how the installation was started. That means you will have to boot your FAI installation using UEFI as well. This can be a bit tricky if you want to install from network - I also tried setting up PXE with UEFI some time ago and failed.
   Bye,
   Andreas

   I am pretty sure it is not possible to set up grub-efi correctly when booted in legacy mode. While it is possible to detect that we are actually running an EFI-capable machine (dmidecode or lshw can detect that), we cannot access the efi variables under /sys/efi since the firmware doesn't expose them to the host when running under CSM aka "Legacy mode".

   Booting from USB with UEFI is possible, in fact I have such a USB device here somewhere. But I need to remember what I did, it was not (yet) completed in FAI at that time. I remember I wanted to make some patches available, but never found the time. This is almost a year ago now. What you basically need is a small FAT partition preferrably of type 'ef' (EFI Boot Partition) on the USB drive, which contains a grub efi image as EFI/BOOT/BOOTX64.EFI. That image can be created with grub-mkimage and needs to include at least all modules for reading the "main" partition and the grub.cfg on it. That will be mostly ext filesystem and msdos partition table, I think. That image should also include an embedded config file with a one-liner like
   configfile (hd0,msdos1)
   if the main partition is the second on the USB drive.

   I will try to find this again and post it here.

   Bye,
   Andreas



























































































































































-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.uni-koeln.de/pipermail/linux-fai/attachments/20180418/2c60f0b9/attachment-0001.html>