Arch: TTY boot from GRUB

Boot to TTY from GRUB menu:

    1. Boot to the GRUB menu.
    2. Highlight the Arch Linux boot entry.
    3. Press e to edit the boot parameters.
    4. Find the line that starts with "linux" and append to the end " systemd.unit=multi-user.target" or " 3" (relying on legacy compatibility mapping of runlevel 3).
    5. Press F10 or Ctrl + X to boot with these options.    NOTE: This is temporary, does not apply to future startups.

    NOTE: systemd.unit=multi-user.target is text mode (like runlevel 3).
          systemd.unit=graphical.target is GUI mode (like runlevel 5).
          Appending 3 to the kernel parameters in GRUB is a legacy method from the SysV init system.
          It still works works in many systemd-based systems because systemd provides compatibility by mapping runlevels to targets.

Boot to SDDM from TTY:

    $ sudo systemctl start sddm

    NOTE: If SDDM fails to start check for issues: $ journalctl -xeu sddm

    TIP: Set up an alias: $ echo "alias gui='sudo systemctl start sddm'" >> ~/.bashrc

Boot to KDE (skip SDDM) from TTY:

    $ exec dbus-run-session startplasma-wayland

    TIP: Set up an alias: $ echo "alias gui2='exec dbus-run-session startplasma-wayland'" >> ~/.bashrc

Adding a persistent TTY boot option to the GRUB menu:

    NOTE: The new boot option will appear at the end of the list of options.

    SOURCE: https://www.gnu.org/software/grub/manual/grub/html_node/Simple-configuration.html
    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.

    SOURCE: https://www.linux.org/threads/grub-menu-entry-to-boot-to-tty.44508/
    1. Copy a working menuentry from /boot/grub/grub.cfg into /etc/grub.d/40_custom.
    2. Change its name to [menuentry 'Arch Linux TTY'] or whatever.
    3. Add "systemd.unit=multi-user.target" or "3" (relying on legacy compatibility mapping of runlevel 3) to the end of the "linux" line.

        Example:

            /etc/grub.d/40_custom

            #!/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.

            menuentry 'Arch Linux TTY' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-6d3bcf47-8794-4335-b408-7385d219f284' {
                load_video
                set gfxpayload=keep
                insmod gzio
                insmod part_gpt
                insmod ext2
                search --no-floppy --fs-uuid --set=root 6d3bcf47-8794-4335-b408-7385d219f284
                echo    'Loading Linux linux ...'
                linux   /boot/vmlinuz-linux root=UUID=6d3bcf47-8794-4335-b408-7385d219f284 rw  loglevel=3 quiet nvidia_drm.modeset=1 nvidia_drm.fbdev=1 nvidia.NVreg_EnableGpuFirmware=0 nvidia-drm.gsp_disable=1 systemd.unit=multi-user.target
                echo    'Loading initial ramdisk ...'                                                                                                                                                           # ^-- Added to make this entry boot to TTY.
                initrd  /boot/intel-ucode.img /boot/initramfs-linux.img
            }

    4. $ sudo grub-mkconfig -o /boot/grub/grub.cfg