GDM is a system service that is responsible for providing graphical logins and managing local and remote displays.
![[Note]](../images/note.png)
Development versions of BLFS may not build or run some packages properly if LFS or dependencies have been updated since the most recent stable versions of the books.
Download (HTTP): https://download.gnome.org/sources/gdm/48/gdm-48.0.tar.xz
Download MD5 sum: a17868752c9a90ed560891886f2882f2
Download size: 920 KB
Estimated disk space required: 44 MB
Estimated build time: 0.2 SBU
AccountsService-23.13.9, DConf-0.40.0, libcanberra-0.30 (built after GTK-3.24.51), and Linux-PAM-1.7.1
keyutils-1.6.3 and check (for testing)
It is recommended to have a dedicated user and group to take
control of the gdm
daemon after it is started. Issue the following commands as the
root user:
groupadd -g 21 gdm &&
useradd -c "GDM Daemon Owner" -d /var/lib/gdm -u 21 \
-g gdm -s /bin/false gdm &&
passwd -ql gdm
First, adapt GDM to build with GCC 15:
sed -r 's/([(*])bool([) ])/\1boolval\2/' -i common/gdm-settings-utils.*
Install GDM by running the following commands:
sed -e 's@systemd@elogind@' \
-e 's/-session optional/-session required/' \
-e '/elogind/isession required pam_loginuid.so' \
-i data/pam-lfs/gdm-launch-environment.pam &&
mkdir build &&
cd build &&
meson setup .. \
--prefix=/usr \
--buildtype=release \
-D gdm-xsession=true \
-D initial-vt=7 \
-D run-dir=/run/gdm \
-D logind-provider=elogind \
-D systemd-journal=false \
-D systemdsystemunitdir=no \
-D systemduserunitdir=no &&
ninja
The test suite requires Check that we've removed from LFS.
Now, as the root user:
ninja install
--buildtype=release:
Specify a buildtype suitable for stable releases of the package, as
the default may produce unoptimized binaries.
-D initial-vt=7: This
switch starts GDM on VT7 by default, since on SysV systems, elogind
is not available until it gets activated by PAM during a login
session. The default behavior is to start on the currently active
TTY, but this behavior causes GDM to fail to start in virtual
environments and other situations where Wayland is not supported.
-D default-pam-config=lfs: Use this
switch if you did not create the /etc/lfs-release file or distribution auto
detection will fail and you will be unable to use GDM.
-D gdm-xsession=true: This
enables the installation of the GDM Xsession file.
The GDM daemon is configured using the /etc/gdm/custom.conf file. Default values are
stored in GSettings in the gdm.schemas file. It is recommended that
end-users modify the /etc/gdm/custom.conf file because the schemas
file may be overwritten when the user updates their system to
have a newer version of GDM.
On some systems with NVIDIA GPUs or virtual GPUs (such as
provided by qemu), GDM will hide Wayland sessions by default.
This is often done to prevent users from encountering problems
with buggy drivers, which can result in system lockups,
application crashes, power management problems, and graphics
slowdowns. If your system is a virtual machine or you have an
NVIDIA GPU and still want to try running Wayland sessions anyway,
execute the following command as the root user:
ln -s /dev/null /etc/udev/rules.d/61-gdm.rules
To start gdm
automatically when the system is switched to runlevel 5, install
the /etc/rc.d/init.d/xdm script and
the /etc/sysconfig/xdm
configuration file included in the blfs-bootscripts-20250225 package and
adjust /etc/inittab by running as
the root user:
make install-gdm
In order to permanently set the default runlevel to 5, starting
the gdm greeter
screen automatically, you can modify /etc/inittab. As the root user:
sed /initdefault/s/3/5/ -i /etc/inittab
GDM will suspend the system when the greeter screen has been
running for a while without any interactive input. If you want to
disable auto-suspending for any reason (for example if the system
is hosting some services besides functioning as a desktop
system), as the root user, issue:
su gdm -s /bin/bash \
-c "dbus-run-session \
gsettings set org.gnome.settings-daemon.plugins.power \
sleep-inactive-ac-type \
nothing"