From: torvalds@klaava.Helsinki.FI (Linus Torvalds) Subject: Re: Coherent vs. Linux - a comparo Date: 23 Jun 1993 19:47:41 +0300
In article <23JUN199309285799@mpx1.lampf.lanl.gov> odonnell@mpx1.lampf.lanl.gov (J. M. O'Donnell) writes:
>In article <umunk.740677666@naxos>, munk.pad@sni.de writes...
>>
>>Yes, but the DOS emulator can't run Windows 3.1 in enhanced 386 mode.
>>Also I'm really wondering how long you are willing to support and use
>>DOS/Windows anymore, when you can have UNIX/X11 on your box.
>>I prefer it to boot DOS when I sometimes want to run a DOS
>>application, I'm really happy that the COHERENT kernel isn't blown
>>up with a DOS emulator. I would like to hear from someone, which
>
>I thought the Linux DOS emulator was a separate utility?
>So surely it doesn't inflate the kernel?
It doesn't. The vm86-mode support in the kernel proper is only around
100 lines of C or so. It was actually a bit tricky to implement, as it
does need mm support and support from the low-level interrupt handlers,
but once that is handled, vm86 is very easy to do, and the mm rewrite I
did to get it working cleanly actually resulted in better memory
management even for normal unix programs. The actual DOS emulator is a
normal user-mode program.
Linus