From: adhamilt@gmail.com 
  
 Hello, 
  
  
  
 On Fri, Sep 26, 2025 at 12:33€€€AM Askar Safin via Grub-devel < 
 grub-devel@gnu.org> wrote: 
 > 
 > Hi, GRUB people. 
 > 
 > (debian-kernel is in "To" for reasons explained below.) 
 > 
 > Currently GRUB has a bug: on UEFI "insmod all_video" seems to enable 
 wrong video driver and/or 
 > multiple video drivers at once instead of enabling "efi_gop" and nothing 
 else. 
 > 
 > This causes video artifacts when we run GRUB inside of Qemu and chainload 
 EFI shell. 
 > EFI shell becomes unusable. 
 > 
 > Also this sometimes affects Linux kernel: makes it unusable in early boot 
 stages (more details below). 
 > 
 > This problem is urgent for reasons explained below. 
 > 
 > See full bug report, including full reproduction steps, here: 
 https://gitlab.com/qemu-project/qemu/-/issues/2562 . 
 > In this report Qemu people gave detailed answers why this bug happens. 
  
 Thank you for the detailed reproduction steps / script in the Qemu report, 
 that was very helpful to understand and recreate it. 
  
  
 > 
 > Qemu people rejected my report. They said the problem is in GRUB and/or 
 its configuration. 
 > 
 > I reported this to GRUB: https://savannah.gnu.org/bugs/index.php?66200 , 
 > but I got no answer for a year. 
 > Does anybody read bug tracker at all? 
  
 I personally do check it and try to fix all the ones I have the time to and 
 that align to the project priorities, in my personal time.. I think some of 
 the people on the mailing list have been swamped with other priorities for 
 the project. 
  
  
 > 
 > So, I kindly ask GRUB people to make "insmod all_video" equivalent 
 > to "insmod efi_gop" in UEFI mode. I. e. in UEFI mode no drivers should be 
 > enabled except for efi_gop. (The same applies to use case, when we 
 > build GRUB image using "grub-mkimage ... all_video".) 
 > 
 > It is possible to workaround at configuration side, i. e. not to invoke 
 > "insmod all_video" in grub.cfg in UEFI mode and not to pass "all_video" 
 > to "grub-mkimage -O x86_64-efi ...". 
 > 
 > I tested that this workaround indeed works. 
 > 
 > But I still believe that this problem should be fixed at core GRUB side, 
 i. e. 
 > I think that calling "insmod all_video" should not cause problems on its 
 own. 
 > 
 > It seems that "insmod all_video" enables "video_bochs", which causes the 
 problem. 
 > (I tested that "insmod video_bochs; insmod efi_gop" is buggy and just 
 "insmod efi_gop" 
 > works. Bochs is output used by Qemu by default.) 
 > 
 > So I ask GRUB devs: do you agree that this should be fixed in GRUB itself? 
  
 I wonder, is there any valid use case for the bochs driver to be built in 
 efi configuration? I assume efi must provide that gop interface? 
  
  That seems like a possibly simple fix€€€ to remove bochs for efi so it 
 isn€€€t 
 loaded by all video. 
  
 > 
 > If not, then I will submit instead PR to Debian to fix the bug at 
 configuration side. 
 > (Debian is distro I use.) 
 > 
 > Also: if I run current Debian sid inside of Qemu, then this bug affects 
 not only EFI shell, 
 > but also Linux kernel. When GRUB transitions to Linux, image is damaged 
 at first 
 > (i. e. Linux is unusable), but then image becomes normal when Linux 
 switches to 
 > native driver. This problem can be fixed by replacing "all_video" with 
 "efi_gop", too. 
 > 
 > Now let me explain why this is urgent. Debian tries to enable 
 CONFIG_DRM_SIMPLEDRM=y 
 > for its kernels: 
 https://salsa.debian.org/kernel-team/linux/-/merge_requests/1453 . 
 > Unfortunately, Ben Hutchings (CC'd) says that Linux output is broken: 
 > 
 https://salsa.debian.org/kernel-team/linux/-/merge_requests/1453#note_605334 
 . 
 > Assuming that he sees this in Qemu (in UEFI mode), this seems to be 
 exactly that bug I'm speaking about. 
 > 
 > So, this problem prevents Debian from enabling CONFIG_DRM_SIMPLEDRM=y 
 > (it is already enabled by Fedora). 
 > 
 > Finally, here is patch: https://paste.debian.net/1398161/ , 
 > which fixes this bug at configuration side for Debian's GRUB. 
 > It is not designed to be applied right now, I send it just to 
 > allow Debian people to proceed right now without waiting 
 > for GRUB people first. 
 > 
 > -- 
 > Askar Safin 
 > https://types.pl/@safinaskar 
 > 
 > 
 > _______________________________________________ 
 > Grub-devel mailing list 
 > Grub-devel@gnu.org 
 > https://lists.gnu.org/mailman/listinfo/grub-devel 
  
 Please let me know your thoughts. 
  
 Thanks, 
 Andrew 
  
 
Hello,

 
 
 
 
 
 On Fri, Sep 26, 2025 at 12:33€€€AM Askar Safin via Grub-devel <grub-devel@gnu.org> 
 wrote:
 
 >
 
 > Hi, GRUB people.
 
 >
 
 > (debian-kernel is in "To" for reasons explained below.)
 
 >
 
  
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