This was the output I got from re-installing GRUB within an RTAI kernel:
Code:
Summary:
Upgrading: 0, Installing: 0, Reinstalling: 1, Removing: 0, Not Upgrading: 0
Download size: 45.9 kB
Space needed: 0 B / 113 GB available
Get:1 http://deb.debian.org/debian sid/main amd64 grub-efi-amd64 amd64 2.12-2 [45.9 kB]
Preconfiguring packages ...
Fetched 45.9 kB in 0s (382 kB/s)
(Reading database ... 414003 files and directories currently installed.)
Preparing to unpack .../grub-efi-amd64_2.12-2_amd64.deb ...
Unpacking grub-efi-amd64 (2.12-2) over (2.12-2) ...
Setting up grub-efi-amd64 (2.12-2) ...
Installing for x86_64-efi platform.
grub-install: warning: EFI variables cannot be set on this system.
grub-install: warning: You will have to complete the GRUB setup manually.
Installation finished. No error reported.
Generating grub configuration file ...
Found background image: /usr/share/images/desktop-base/desktop-grub.png
Found linux image: /boot/vmlinuz-6.9.7-amd64
Found initrd image: /boot/initrd.img-6.9.7-amd64
Found linux image: /boot/vmlinuz-5.4.278-rtai-amd64
Warning: os-prober will be executed to detect other bootable partitions.
Its output will be used to detect bootable binaries on them and create new boot entries.
Found Debian GNU/Linux trixie/sid on /dev/nvme0n1p6
Adding boot menu entry for UEFI Firmware Settings ...
done
Processing triggers for shim-signed:amd64 (1.44+15.8-1) ...
When you see:
Code:
grub-install: warning: EFI variables cannot be set on this system.
grub-install: warning: You will have to complete the GRUB setup manually.
This is because EFI support is disabled in the RTAI kernel. Latency spikes may happen when it's enabled so I have it forcibly disabled through Kconfig, so you won't be able to modify the boot order through efibootmgr or delete/create entries.
/boot/grub/grub.cfg still updates just fine though and that's the main thing. If you want to modify EFI boot parameters you'll need to reboot into a Debian kernel and do it then.
I'm using a local branch of RTAI which has the kernel updated to 5.4.278, I can't test my changes because the laptop I'm currently using throws kernel panics whenever RTAI loads so I won't push until I can verify my changes are OK.
