I got a HTPC box running arch, connected to my TV with a HDMI cable. It currently boots directly into XBMC and I remote onto it using SSH when needed. My TV is not super far away from my desk in my living room, and I'm thinking about hooking the DVI output (and the keyboard/mouse) into a KVM.
Now, my question is, in a perfect world, I would like to be able to boot it in two different manners. One which starts XMBC automatically, using just one screen (the TV), and one which boots it onto a login manager, and then after login gives me a dual screen configuration, which XMBC on the TV and and gnome on the other screen.
I know that could have two different grub entries, and boot one into runlevel 3 and manually start gdm, but it could be awesome if I could just have it happen automatically. So, both starts into runlevel 5, but with the different behaviour described above.
Is this possible?
It's rather easy to do this with systemd. If you're not using systemd for some reason, you can use runlevel 4.
Add "systemd.unit=<name>.target" to the kernel boot line and make a new target file in /etc/systemd/system/<name>.target. Copy it from default.target and just change what you need to change.