Comment by bjackman
Pretty cool!
> The reliance on VirtIO means Munal OS does not support running on real hardware yet
I think if you wanted to run it on HW, instead of running adding drivers to it a cool strategy would be to build a Linux-based system that acts as a bootloader and then starts a minimal hypervisor. Then you could keep the "virtio is the platform" thing.
It would be quite cool how you end up using VirtIO as the platform for the OS in the same way that you use WASM as the platform for applications.
For what it's worth, as a platform security nerd, unfortunately I do think we need to use the MMU. But, a cool realisation with your design is that it doesn't mean we need virtual memory, you could keep the identity mapping and just use the protection bits. Unfortunately that still takes away a big part of your simplification since now you need multiple set of pagetables, need to manage TLB flushes, etc.
> I think if you wanted to run it on HW, instead of running adding drivers to it a cool strategy would be to build a Linux-based system that acts as a bootloader and then starts a minimal hypervisor. Then you could keep the "virtio is the platform" thing.
That's what I did with my last hackintosh attempt and it works pretty well. The downside: without real GPU events to respond to, you'd be stuck with whatever resolution Linux decided upon in whatever screen configuration Linux decided to boot.
If this thing can run as a UEFI executable rather than a real OS, you might be able to use the UEFI video drivers to get video working relatively easily without having virtio graphics, but I'm not sure if it's even possible to pull that off while doing real OS things.