Sometimes, programming is just for fun. This is what PREPHV is for Andrei Warkentin. To quote the README:

“This is mostly a huge ugly hack, derived from my
ppc64le_hello code. The running philosophy here is
to throw things together late at night with my family
asleep and see how far I get without a real design
or without a real desire to implement boring things
like IDE (*sigh*) emulation”

Since my day job is maintaining the firmware that it runs on, I decided to have a go (it also ties in with the retro stuff I’ve been blogging about). So…

and I’m off! (yes, this is the very latest qemu and skiboot):

Yes, prephv does clear all thirty two megabytes of guest memory

A quick diversion, if you try Windows NT 3.51 for PowerPC, you get this:

But on NT4, you continue unharmed:

A sign I needed to hack my filesystem of bits of NT installer bits a bit more:

But, on my next try:

Well… looks like there’s an instruction that needs to be emulated (and there’s no code to currently do that). Mind you… this is decently far into booting before we hit anything fatal, which is a pretty impressive effort – and it is tempting to continue and see if it’ll run on real hardware and if it could be made to work well enough to not find any disks :)