Recently, Gnome and Budgie on Arch Linux Arm is failing to start GDM.
systemctl status gdm.service
Jul 03 18:26:44 RPi4-32 systemd[1]: Starting GNOME Display Manager
Jul 03 18:26:45 RPi4-32 systemd[1]: Started GNOME Display Manager
Jul 03 18:27:29 RPi4-32 gdm[397]: Gdm: GdmDisplay: Session never registered, failing
journalctl -u gdm
gives the same results.
Help. I have no idea what “Session never registered”. What was gdm trying to register with?
I suspect pam may be involved?
Pudge
You can try to use xorg backend instead of default (which is wayland)
in /etc/gdm/custom.conf
uncomment/add WaylandEnable=false
little of topic 
it on same line, i get lightdm login problem on sway ATM . i dig deeper later + see what find
Still doesn’t work. It did come closer to working after this, as it now attempts to bring up gdm. The top panel now appears but it never finishes the login area.
I wrote the Original Post when I was in a hurry. Mistake. Further details:
I am trying to install Gnome on a Raspberry Pi 4b on a 32 Bit OS.
If I install Gnome on the same RPi 4b with the 64 Bit OS, it works.
I have not figured out why. The package list should be the same for both the 32 Bit and 64 Bit versions. Go figure.
Pudge
That’s weird, I have a feeling that’s GPU related, you can try to start KMS early https://wiki.archlinux.org/title/Kernel_mode_setting#Early_KMS_start or
force a specific resolution or
set/force gpu memory (gpu_mem to 512 or 256) or
downgrade systemd
It’s a long shot but maybe something will work
Thank you for the suggestions. I am hoping to have some time to work on this later today.
The Raspberry Pi 4b can run on either a 32 Bit OS or a 64 Bit OS. If I install using the 64 Bit OS this problem does not exist. If I install using the 32 Bit OS, it will not boot into GDM.
The aarch64 linux-raspberrypi4 is the 64 Bit kernel
The armv7h linux-raspberrypi4 is the 32 Bit kernel
Both kernels are version 5.10.48-1
I know nothing about compiling a kernel. I am wondering if the 64 Bit kernel is compiled with a flag or module that is missing when the 32 Bit kernel is compiled?
Hete is the source files for the kernel
Looking at the PKGBUILD, everything is the same for both 32 Bit and 64 Bit EXCEPT the PKGBUILD uses “config” for the 32 bit, and “config8” for the 64 bit. There are differences between the two which is to be expected. Otherwise they wouldn’t use two different files.
Unfortunately I am not knowledgeable enough to decipher what is going on.
Pudge