On Mon, 19 Feb 2024 08:10:35 +0100 Florian Märkl <open...@florianmaerkl.de> wrote:
> Until just now, I assumed the powerpc64 variant of OpenBSD was little > endian, but apparently it is big endian, which would be promising for > the G5. I am not too familiar with the details about other potential > differences other than that between macppc and powerpc64 unfortunately, > but I would be very curious about how feasible OpenBSD/powerpc64 is for > G5s as well. The powerpc64 kernel uses OPAL, but the G5 has Open Firmware, not OPAL. This kernel prints messages to OPAL's serial console; it doesn't know how to draw on the G5's display. Peter J. Phillip tried in 2021 to boot powerpc64 on G5, but failed to "get something printed on my monitor", https://marc.info/?l=openbsd-ppc&m=161951979429165&w=2 I imagine that the first goal might be to netboot a demo that draws on the display in 64-bit mode. The second goal might be to copy a device tree out of Open Firmware. Then one might begin to adapt drivers like openpic(4) and gem(4) from macppc to powerpc64, until the system can netboot successfully. One must also edit some asm; for example, the floating-point code assumes VSX, but G5 has no VSX. It would be a big kernel project. I want to keep my G5 on macppc but there are other G5 people who would try powerpc64 if it became ready. --gkoehler
