grub2 user interface disappears after upgrade from stretch to testing

[Shane Dev]

Hello, I downloaded firmware-9.6.0-amd64-netinst.iso and successfully
installed a minimal debian stretch on my UEFI/GPT disk. After rebooting, I
was presented with the grub2 text user interface and the possibility to
boot Debian or my Windows boot manager - as expected.

Following https://wiki.debian.org/DebianTesting, I
edited /etc/apt/sources.list and changed stretch to testing, apt update &&
apt upgrade. Everything seemed ok but when I rebooted, the grub2 user
interface was gone and I could not find a way to boot Debian. Any ideas?

Shane

[Felix Miata]

Post by Shane Dev
Hello, I downloaded firmware-9.6.0-amd64-netinst.iso and successfully
installed a minimal debian stretch on my UEFI/GPT disk. After rebooting, I
was presented with the grub2 text user interface and the possibility to
boot Debian or my Windows boot manager - as expected.
Following https://wiki.debian.org/DebianTesting, I
edited /etc/apt/sources.list and changed stretch to testing, apt update &&
apt upgrade. Everything seemed ok but when I rebooted, the grub2 user
interface was gone and I could not find a way to boot Debian. Any ideas?

By "gone", do you mean an entirely black screen? Or, do you see a few lines
of help text followed by a

grub> _

prompt? If the latter you can type in, along with tab completion, the commands
to load "linux" and "initrd", just like a grub menu does for you, except you don't
actually need everything the defaults usually provide, as any of it is necessary
is included in the initrd. Those you need should be in your backup of grub.cfg.

If you're getting nothing, try using your BIOS boot selection menu, which may
have been poorly changed by the upgrade process to in inappropriate choice.
Without actually entering BIOS setup it could be F12, F8, F9 or a number of
other keystrokes that are firmware dependent.

If you can't find your grub.cfg backup, use the following from one of mine as
a template:

load_video
set gfxpayload=keep
search --no-floppy --set=root --hint-baremetal=ahci0,gpt10 --label p10deb10
linux /boot/vmlinuz root=LABEL=p10deb10 noresume
initrd /boot/initrd

[Shane Dev]

Hi Felix,

Thanks for your fast reply. From memory, I think the grub2 text menu
installed by firmware-9.6.0-amd64-netinst.iso became a grub command line
prompt after upgrading to testing.

1. For what possible reasons could have my grub menu disappeared?
2. You suggest I could boot Debian with "linux" and "initrd" commands. How
could I determine which parameters to pass to these commands?

Post by Felix Miata

Post by Shane Dev
Hello, I downloaded firmware-9.6.0-amd64-netinst.iso and successfully
installed a minimal debian stretch on my UEFI/GPT disk. After rebooting,

I

Post by Shane Dev
was presented with the grub2 text user interface and the possibility to
boot Debian or my Windows boot manager - as expected.
Following https://wiki.debian.org/DebianTesting, I
edited /etc/apt/sources.list and changed stretch to testing, apt update

&&

Post by Shane Dev
apt upgrade. Everything seemed ok but when I rebooted, the grub2 user
interface was gone and I could not find a way to boot Debian. Any ideas?

By "gone", do you mean an entirely black screen? Or, do you see a few lines
of help text followed by a
grub> _
prompt? If the latter you can type in, along with tab completion, the commands
to load "linux" and "initrd", just like a grub menu does for you, except you don't
actually need everything the defaults usually provide, as any of it is necessary
is included in the initrd. Those you need should be in your backup of grub.cfg.
If you're getting nothing, try using your BIOS boot selection menu, which may
have been poorly changed by the upgrade process to in inappropriate choice.
Without actually entering BIOS setup it could be F12, F8, F9 or a number of
other keystrokes that are firmware dependent.
If you can't find your grub.cfg backup, use the following from one of mine as
load_video
set gfxpayload=keep
search --no-floppy --set=root --hint-baremetal=ahci0,gpt10 --label p10deb10
linux /boot/vmlinuz root=LABEL=p10deb10 noresume
initrd /boot/initrd
--
Evolution as taught in public schools is religion, not science.
Team OS/2 ** Reg. Linux User #211409 ** a11y rocks!
Felix Miata *** http://fm.no-ip.com/

[Felix Miata]

Post by Shane Dev
Thanks for your fast reply. From memory, I think the grub2 text menu
installed by firmware-9.6.0-amd64-netinst.iso became a grub command line
prompt after upgrading to testing.
1. For what possible reasons could have my grub menu disappeared?

You're using "testing". Bugs are to be expected at least on occasion. Sometimes
BIOS quirks interfere with Grub setup commands. UEFI BIOS writers probably do
not spend much time debugging their use with Linux and Grub. UEFI code still
has more maturing to do before consistency among different machines' behavior
can be expected.

Post by Shane Dev
2. You suggest I could boot Debian with "linux" and "initrd" commands. How
could I determine which parameters to pass to these commands?

This is why I mentioned your backup grub.cfg file and provided a template from
one of my own systems.

The initrd line needs only the fullpath of the initrd to be loaded. The linux
line may work with no more than the same. Most cmdline options used in Grub
linux lines are options, meaning not necessary to a successful boot. The stanza
lines preceding the linux line may or may not be required. All you can do is
try, preferably based upon your backup. If you can't locate a backup, retrieve
the grub.cfg file via a rescue boot and work from it. Make use of tab completion
to get the appropriate names of kernel and initrd.

[Shane Dev]

Hello,

I reinstalled stretch (bare minimum packages), then I replaced all
references to "stretch" with "testing" in /etc/apt/sources.list and
executed sudo apt update; sudo apt install gnome-core firefox-esr.
Everything works as expected but I have the following questions -

1. according to uname -r, I am running 4.9.0-7-amd64 which appears to be
the stretch kernel. Is it safe to run the stretch kernel with programs /
apps / utilities from testing?
2. I noticed the intel-microcode package is not installed. If I install it,
could this testing version conflict with the stretch kernel?
3. Last time I tried apt upgrade, my grub menu was replaced with the grub
command prompted. If there any way to avoid this happening again?

Post by Felix Miata

Post by Shane Dev
Thanks for your fast reply. From memory, I think the grub2 text menu
installed by firmware-9.6.0-amd64-netinst.iso became a grub command line
prompt after upgrading to testing.
1. For what possible reasons could have my grub menu disappeared?

You're using "testing". Bugs are to be expected at least on occasion. Sometimes
BIOS quirks interfere with Grub setup commands. UEFI BIOS writers probably do
not spend much time debugging their use with Linux and Grub. UEFI code still
has more maturing to do before consistency among different machines' behavior
can be expected.

Post by Shane Dev
2. You suggest I could boot Debian with "linux" and "initrd" commands.

How

Post by Shane Dev
could I determine which parameters to pass to these commands?

This is why I mentioned your backup grub.cfg file and provided a template from
one of my own systems.
The initrd line needs only the fullpath of the initrd to be loaded. The linux
line may work with no more than the same. Most cmdline options used in Grub
linux lines are options, meaning not necessary to a successful boot. The stanza
lines preceding the linux line may or may not be required. All you can do is
try, preferably based upon your backup. If you can't locate a backup, retrieve
the grub.cfg file via a rescue boot and work from it. Make use of tab completion
to get the appropriate names of kernel and initrd.
--
Evolution as taught in public schools is religion, not science.
Team OS/2 ** Reg. Linux User #211409 ** a11y rocks!
Felix Miata *** http://fm.no-ip.com/