Installing OpenBSD on the Pinephone might seem straightforward, as the hardware is essentially just an arm-based SBC with a built in screen and modem. The Allwinner A64 SoC is supported by the OpenBSD kernel, so we can at least expect it to boot.
However, no specific support for the Pinephone hardware is included in the most recent OpenBSD release at the time of writing, making it unlikely that we'll get much beyond output via the serial terminal.
Furthermore, unlike many SBCs, the Pinephone doesn't have an on-board ethernet connection. This will make the installation slightly more complicated, as we can't install the base packages from a local network server.
Nevertheless, if OpenBSD is ever going to run in a usable fashion on the Pinephone we need to start somewhere.