Bug#1024447: grub-efi-amd64: No box border characters in boot menu

[Steve McIntyre]

Hi Chris,

On Sat, Nov 19, 2022 at 05:28:27PM +0100, Chris Nospam wrote:
>Package: grub-efi-amd64
>Version: 2.06-5
>Severity: normal
>X-Debbugs-Cc: chris21k at gmx.de
>
>Dear Maintainer,
>
>I am running debian testing/bookworm. After the updates from grub 2.06-4 to
>grub 2.06-5 (about November 18th) in the grub boot menu the box border
>characters are not shown as they should. Insteadn one sees only a boxed
>question mark for each character. Further, an error message is shown as text
>for a fraction of a second directly before the boot menu arsises:
>"error: prohibited by secure boot policy."
>I believe this is new in 2.06-5.
>When I disable secure boot with the mainboard firmware, the characters/boot
>menu shows
>up correctly.
>
>I can trigger this in my kvm virtualized installtion and on my bare metal
>machine with an ASUS H170 Gaming main board (and latest firmware).

ACK. Thanks for your bug report!

This is due to a change in Secure Boot setup that came with the latest
GRUB security fixes, to reduce the possibility of security issues in
font handling. With SB enabled, GRUB will now only allow the use of
fonts directly embedded within the signed image. We didn't have the
time to fully convert Debian's GRUB configuration to match this new
world before publishing these security fixes, hence you're seeing
these issues. Sorry. :-(

I'm working to get this fixed up, but it's taking a little longer than
I hoped.

-- 
Steve McIntyre, Cambridge, UK.                                steve at einval.com
"The problem with defending the purity of the English language is that
 English is about as pure as a cribhouse whore. We don't just borrow words; on
 occasion, English has pursued other languages down alleyways to beat them
 unconscious and rifle their pockets for new vocabulary."  -- James D. Nicoll