On 04/02/2020 00.26, Paolo Bonzini wrote: > > > Il mar 4 feb 2020, 00:20 Alexey Kardashevskiy <a...@ozlabs.ru > <mailto:a...@ozlabs.ru>> ha scritto: > > Speaking seriously, what would I put into the guest? > > Only things that would be considered drivers. Ignore the partitions > issue for now so that you can just pass the device tree services to QEMU > with hypercalls. > > Netboot's dhcp/tftp/ip/ipv6 client? It is going to be another SLOF, > smaller but adhoc with only a couple of people knowing it. > > > You can generalize and reuse the s390 code. All you have to write is the > PCI scan and virtio-pci setup.
Well, for netbooting, the s390-ccw bios uses the libnet code from SLOF, so re-using this for a slim netboot client on ppc64 would certainly be feasible (especially since there are also already virtio drivers in SLOF that are written in C), but I think it is not very future proof. The libnet from SLOF only supports UDP, and no TCP. So for advanced boot scenarios like booting from HTTP or even HTTPS, you need something else (i.e. maybe grub is the better option, indeed). Thomas