The xinit package contains a usable script to start the xserver.
This package is known to build and work properly using an LFS 12.3 platform.
Download (HTTP): https://www.x.org/pub/individual/app/xinit-1.4.3.tar.xz
Download MD5 sum: 2f82c02a9408cbb5a6191c4b62763438
Download size: 156 KB
Estimated disk space required: 1.6 MB
Estimated build time: less than 0.1 SBU
          twm-1.0.12,
          xclock-1.1.1, and xterm-397 (used in the default
          xinitrc file)
        
Install xinit by running the following commands:
./configure $XORG_CONFIG --with-xinitdir=/etc/X11/app-defaults && make
This package does not come with a test suite.
          Now, as the root user:
        
make install && ldconfig