From: Drew Eckhardt (drew@juliet.cs.colorado.edu)
Date: 04/14/93


From: drew@juliet.cs.colorado.edu (Drew Eckhardt)
Subject: Re: Has anyone run Minix 1.5 in the DOS emulator?
Date: Thu, 15 Apr 1993 03:56:56 GMT

In article <1qhbm8INNh26@tamsun.tamu.edu> n217cg@tamuts.tamu.edu (Scott Taylor) writes:
>Due to an end-of-semester project in my operating systems class, I need to run
>Minix 1.5 on my PC. Rather than having to reboot whenever I need to work on
>it, I thought it would be really cool to run it in the DOS emulator. The
>problem is that even the universal boot diskette (which only uses BIOS calls to
>access the HW) won't boot in dosemu 0.48; I suspect that all the BIOS calls
>that Minix wants aren't there.

I also had an end-of-semester project (add symbolic links to Minix) in my
operating class, needed to run Minix 1.5 on my PC, and looked at doing the
same thing.

I looked at the device drivers, and discovered that while there's a
disk driver (kernel/bios_wini.c) that uses the BIOS only (ie, for
SCSI disks, etc) all of the other drivers (console, serial, etc)
all talk directly to the hardware.

I figured that virtualizing Minix (either by hacking DOS emu to do the
appropriate hardware emulation, writing BIOS using device drivers, or hacking
Minix to run as a *normal* Linux process) would add more time to the project
than a virtualized Minix would save, and finished the project in eight hours
(four hours of writing code, four of debugging, mostly tracking down a
int / off_t switch that lint / gcc would have caught) editing the Minix
source from Linux under 'X', rebooting to try things out.

>
>Has anyone successfully done this? I don't have a lot of time right now to
>hack dosemu (whatever Linux hacking time I have I intend to spend on the Ultra-
>Stor 14F/34F driver), but if anyone has any "fast & easy" tips, I would really
>appreciate it!
>

It's non-trivial.

-- 
Boycott USL/Novell for their absurd anti-BSDI lawsuit. | Drew Eckhardt
Condemn Colorado for Amendment Two.                    | drew@cs.Colorado.EDU
Use Linux, the fast, flexible, and free 386 unix       |