GLIMMER coreboot 2603+ text mode stretched

Bug Reports Firmware Bugs
1

System Details

  • Device: GLIMMER
  • OS: N/A (cbmem run on an archlinux live iso)
  • Firmware Type: UEFI Full ROM
  • Firmware Version: MrChromebox-2603.2 (05/17/2026)
  • Internal storage type: N/A

cbmem logs: pastes

Summary of the Issue

Before upgrading to MrChromebox-2603.0, the text mode was 170x40 and it filled the screen perfectly. After upgrading to MrChromebox-2603.0 and all the versions after, the highest available text mode is 128x40 and it is stretched to fill the screen. This issue doesn’t affect the operating system.

Steps to Reproduce

  1. Enter the UEFI Shell on MrChromebox-2512.2 and run mode. It returns the highest mode as Col 170 Row 40.

  2. Upgrade to any version above MrChromebox-2512.2.

  3. Enter the UEFI Shell again and run mode. It now returns the highest mode as Col 128 Row 40. Aditionally the boot screen, boot options menu, and uefi shell are all stretched to fill the screen.

Expected Behavior

Upgrading to MrChromebox-2603.0 should have not changed the text mode, especially not making it smaller and stretching the screen.

2

It’s an artifact of switching from the edk2 GOP driver to the older VBIOS for display init in the new release. A decent number of glimmer boards were not happy with the GOP driver. If your device was ok with it, and you want to keep using it, then you can compile the 2603 firmware using the config from glimmer from 2512.

3

Just confirming, that is this file? coreboot/configs/byt/config.glimmer.uefi at MrChromebox-2512 · MrChromebox/coreboot · GitHub

4

yes, that’s correct