Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.debian.kernel > #88708

Bug#1110565: EFI runtime services not available in RT kernel

From Salvatore Bonaccorso <carnil@debian.org>
Newsgroups linux.debian.bugs.dist, linux.debian.kernel
Subject Bug#1110565: EFI runtime services not available in RT kernel
Date 2025-08-08 21:10 +0200
Message-ID <LhADv-65Qy-5@gated-at.bofh.it> (permalink)
References <LhzHr-65e7-9@gated-at.bofh.it> <LhzHr-65e7-9@gated-at.bofh.it>
Organization linux.* mail to news gateway

Cross-posted to 2 groups.

Show all headers | View raw

Control: reassign -1 src:linux
Control: forcemerge 956752 -1

On Fri, Aug 08, 2025 at 08:05:56PM +0200, Information BravoSystems wrote:
> Package: linux-image-rt-amd64
> Version: 6.12.38+deb13-rt
> Severity: normal
> 
> EFI runtime services are not available when booting RT kernel,
> causing applications that depend on EFI variables to fail.
> 
> Steps to reproduce:
> 1. Boot RT kernel
> 2. Check: ls /sys/firmware/efi/efivars/
> 3. Result: Empty
> 
> Expected: EFI variables should be accessible like in non-RT kernel
> 
> Additional info:
> - Non-RT kernel works fine
> - CONFIG_EFIVAR_FS=m in both kernels
> - CONFIG_EFI_DISABLE_RUNTIME is not set in RT kernel
> - Same hardware, different behavior
> 
> When comparing
> 
> grep -E "CONFIG_EFI*" /boot/config-6.12.38+deb13-rt-amd64
> 
> against to
> 
> grep -E "CONFIG_EFI*" /boot/config-6.12.38+deb13-amd64
> 
> The result is,
> 
> debian13:~$ diff config-efi-rt.txt config-efi-no-rt.txt
> 21c21
> < CONFIG_EFI_DISABLE_RUNTIME=y
> ---
> > # CONFIG_EFI_DISABLE_RUNTIME is not set
> 
> Conclusion, On RT kernels seems that CONFIG_EFI_DISABLE_RUNTIME is not set.

This should be the same as #956752 . There is a documented workaround
which you can try in https://bugs.debian.org/1021245#10 .

Regards,
Salvatore

Back to linux.debian.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Bug#1110565: EFI runtime services not available in RT kernel Information BravoSystems <info@bravosystems.es> - 2025-08-08 20:10 +0200
  Bug#1110565: EFI runtime services not available in RT kernel Salvatore Bonaccorso <carnil@debian.org> - 2025-08-08 21:10 +0200
  Processed: Re: Bug#1110565: EFI runtime services not available in  RT kernel "Debian Bug Tracking System" <owner@bugs.debian.org> - 2025-08-08 21:10 +0200

csiph-web