Solved GRUB menu entry to boot to TTY?

[rado84]

Can something be added as GRUB menu entry to boot to TTY? Sometimes the system won't boot the desktop due to broken packages and in most cases I know what has been broken but I can't fix it bc the system hangs moments before booting the desktop. So it would be easier if I can simply choose the option from the menu, instead of restoring from backup every time something breaks.

 

[f33dm3bits]

If the graphical environment doesn't load but the system it booted you can just use the ctrl+alt+f? shortcuts to switch to a tty without having to boot from the Arch live environment to chroot into your system to rescue it. Why would you need to add it to a grub menu, if you can switch to a tty at any moment if it's only the graphical environment fails to load?

 

[osprey]

Can something be added as GRUB menu entry to boot to TTY? Sometimes the system won't boot the desktop due to broken packages and in most cases I know what has been broken but I can't fix it bc the system hangs moments before booting the desktop. So it would be easier if I can simply choose the option from the menu, instead of restoring from backup every time something breaks.

As I understand it, the problem here is that the system hangs, so that getting a console with cntl+alt+F#, may not be available due to a freeze of the system, so you may need to reboot.

One could hack the /boot/grub/grub.cfg file to add a copy of one of the menuentries which already exist in the grub.cfg file, to the end of the file but with an added 3 at the end of its linux line, after a space on that line. Then that linux boot option should appear in the grub menu and if selected, boot to a text prompt. It's a hack, so whenever one updates grub, it will be overwritten and not be available. It's possible to write a script that runs after each grub update one might do, to re-include it.

The usual way I deal with it though is to hit e when grub boots, and then navigate down to the linux line and add the 3 there, hit cntl+x and it boots to a prompt. I hope I've understood the issue.

Another route down this track is to investigate the grub customisation process which involves configuring files in /etc/grub.d/.

From the grub manual:

For more detailed customisation of grub-mkconfig’s output, you may edit the scripts
in ‘/etc/grub.d’ directly. ‘/etc/grub.d/40_custom’ is particularly useful for adding entire
custom menu entries; simply type the menu entries you want to add at the end of that file,
making sure to leave at least the first two lines intact.

and from the /etc/grub.d/40_custom file itself:

#!/bin/sh
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.

You could copy one of the menuentries from /boot/grub/grub.cfg into this file but with the added 3 to have it boot to text. After each config change one needs to update grub of course.

In my own case, that customisation hasn't always been reliable, hence the hack. YMMV.

 

[rado84]

This is the menu entry:

menuentry "Arch 6.x LTS" --class arcolinux --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-advanced-73719eb1-eb34-4234-9a3e-fd86f6999d54' {
        load_video
        set gfxpayload=keep
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd1,msdos1'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd1,msdos1 --hint-efi=hd1,msdos1 --hint-baremetal=ahci1,msdos1  73719eb1-eb34-4234-9a3e-fd86f6999d54
        else
          search --no-floppy --fs-uuid --set=root 73719eb1-eb34-4234-9a3e-fd86f6999d54
        fi
        echo    'Loading Linux linux-lts ...'
        linux    /boot/vmlinuz-linux-lts root=UUID=73719eb1-eb34-4234-9a3e-fd86f6999d54 rw  acpi=force acpi_enforce_resources=lax intel_pstate=disable
        echo    'Loading initial ramdisk ...'
        initrd    /boot/initramfs-linux-lts.img
}

So where, exactly, do I put the number "3"?

 

[osprey]

rado84 asked:

So where, exactly, do I put the number "3"?

At the end of the linux line after a space ... like so:

linux    /boot/vmlinuz-linux-lts root=UUID=73719eb1-eb34-4234-9a3e-fd86f6999d54 rw  acpi=force acpi_enforce_resources=lax intel_pstate=disable 3

 

[rado84]

Cool, I'll try that now.
Also, I'm editing grub.cfg directly myself. Not just now but in principle. Arch wiki says (as I have discovered myself, long before I read it) that directly editing grub.cfg doesn't require you to execute update-grub or whatever that command was. Grub.cfg remains the same as what I've made of it, even if the package grub updates.

Edit, 20 seconds later: Yesss, it works! Thanks, man, that's a cool hack!

 

[osprey]

Cool, I'll try that now.
Also, I'm editing grub.cfg directly myself. Not just now but in principle. Arch wiki says (as I have discovered myself, long before I read it) that directly editing grub.cfg doesn't require you to execute update-grub or whatever that command was. Grub.cfg remains the same as what I've made of it, even if the package grub updates.

Yes, that's the hack I was referring to, and mentioned that a grub update would nullify it. It's for the other "conventional" means of changing the configs that one needs to update grub.