dos in bhyve

[Peter Grehan]

Hi Andriy,

> I wonder if anyone was able to run any DOS variant in bhyve.

  I've run vm86 mode in Linux but that doesn't really count :)

> I tried FreeDOS using BHYVE_UEFI_CSM firmware, but it seems to just hang.

  Try looking at the CSM/BIOS debug output that is available on the 
bvmcons debug port (use bhyve's "-b" option, though you'll want to send 
serial port output to somewhere other than stdout (e.g an nmdm port).

  That will at least show what BIOS calls are being issued, and if any 
are unimplemented.

> I also tried adding a frame buffer device, it seems that there is some reaction
> to key presses (RET) sent via VNC, but the screen stays black, so it's
> impossible to tell if there are any prompts and what happens.

  The VGA renderer hasn't been hooked up in this mode yet (fbuf,vga=on). 
I can work with you offline to get that going.

later,

Peter.