Hi,

  When I boot my notebook use RT kernel, efibootmgr can't use.
I'd report this to #1089080.

# efibootmgr
EFI variables are not supported on this system.

In newest 6.12.3-rt-amd64 kernel, I can run modprobe to load efivarfs module:

root@atzlinux-ce:~# modprobe efivarfs
root@atzlinux-ce:~# lsmod|grep efi
efivarfs               28672  0
efi_pstore             12288  0

But in /sys/firmware/efi/efivars directoy, it still empty.

This bug don't take place in 6.12.3-amd64 kernel, only in Debian RT kernel.


Regards,

xiao sheng wen(atzlinux)

I just found out that you can add

efi=runtime

to the kernel command line if you need efivarfs using rt kernels. It is
documented in
https://docs.kernel.org/core-api/real-time/kernel-configuration.html that
CONFIG_PREEMPT_RT also sets CONFIG_EFI_DISABLE_RUNTIME because calling into
EFI can cause significant latency spikes.


Best regards
Jan