-drive if=virtio,id=sys,file=/path/to/disk.img
-cdrom /path/to/install.iso
-boot order=[sys],once=d,menu=off
Yes, this looks powerful and clean. One could even still define probe
orders like "-boot order=[sys][backup]d".
- This is just an implementation detail: Do we really need to implement
booting from virtio and scsi via an extension rom? Isn't it possible
to merge the corresponding support into the main bios?
Well. There are quite a few. bochs pcbios, seabios, coreboot ...
Ok, but that's only an argument to have extboot as a workaround for
bioses not yet supporting scsi and virtio natively, isn't it? I'm
thinking long-term here, not arguing against a extboot-based short-term
solution.