From: sdw@meaddata.com (Stephen Williams) Subject: Re: Linux and OS/2 Date: 1 Jan 1993 21:24:22 GMT
Jonathan Magid (jem@sunSITE.unc.edu) wrote:
: In article <1992Dec30.174352.4550@gallant.apple.com> erwin#m#_mike.ast_-_tac_mail_server@msgate.corp.apple.com (Mike Erwin) writes:
: >
: >You can't run another whole operating system inside of another
:
: Try telling this to the VM people down the hall!
:
: jem.
:
: --
: Jonathan Magid jem@sunSITE.unc.edu sunSITE Administrator
: Virtual pizza Delivery (tm)::faxed in 30 cycles or less or you get it
: ----------------------------------------FREE!!!-----------------------
Right...
The correct statement is:
"Current Intel 386/486 series cannot nest 'Ring 0' programs in
hardware."
Using other terms:
This means that a 32-bit (Ring 0, priviledged) OS (like all full
Unixes, OS/2, Windows NT, Windows in enhanced mode) cannot run
underneath another with simple hardware modes.
They could run unpriviliged and have the priviliged instructions
emulated.
VM (On IBM compatible Mainframes) does this nesting, either in
hardware or software (I don't know...).
What the world (at least the Unix world) needs right now is a 'virtual
386 mode', where the 386-8086 part is emulated in software. This
would even allow a version of Unix to run under itself. This would be
great for debugging (kernels, startup, etc.).
Additionally, running Windows programs in a 32-bit environment under
Unix and translating (optionally) the video calls (via a special
Windows graphic device driver? which should get high-level commands)
to X would be fantastic.
All it takes is some hard work.
Note that Soft-PC and Sun-PC both emulate at least a 286 in software,
as that is what it takes to run Windows 3.1 (unlike 3.0 which would
run on 8086).
The Sun-PC 486 board even lets you run a full 32-bit application/os's with
full vga mapped efficiently onto X windows.
sdw