Bug#928300: secure boot via removable media path unavailable

[Steve McIntyre <steve@einval.com>]

Hey guys,

Apologies for not getting back to you in better time...

I've just uploaded new shim-signed binaries for all of buster,
bullseye and unstable based on the latest upstream version (15.7). I
can't *promise* that this will fix your issue, but it would be very
helpful if you could try them and let me know please.

The buster upload should be already available via security.debian.org;
the bullseye version is in bullseye-proposed updates if you need to
look.

You'll need to grab the appropriate shim-signed and shim-signed-common
packages together, then install by hand.

If that still doesn't help, the next thing to try is turning on shim
debug using:

$ sudo mokutil --set-verbosity true

This will produce a *lot* of output; if you can capture it via video
or on a serial port, that may help diagnose what's happening.

Thanks!

-- 
Steve McIntyre, Cambridge, UK.                                steve@einval.com
"C++ ate my sanity" -- Jon Rabone