OpenRC is an alternate init system developed by Gentoo developers. OpenRC is a dependency based init system that works with the system provided init program, normally
/sbin/init. It is not a replacement for
OpenRC is available in the AUR. You can choose to install either AUR or AUR package. You will also need to install AUR (provides service files for use with openrc on arch) and AUR.
Once installed the packages you need to add init=/sbin/init-openrc in the kernel boot line of your bootloader configuration.
For booting with OpenRC add
init=/sbin/init-openrc to the kernel line of your bootloader. If you want to go back to systemd replace it with init=/bin/systemd.
For detailed instructions on configuring OpenRC, visit the gentoo guide.
It is worth noting that the udev service is not enabled by default. In order to enable it:
#rc-update add udev default