🚀 go-pugleaf

In article <ENGSTROM.92Dec14083003@moriarty.src.honeywell.com> engstrom@src.honeywell.com (Eric Engstrom) writes:
   GB> So, BSD must be a standard that can be layered on top of different  
   GB> operating systems (e.g. NT, SunOS, and Mach).

   This is where I think your terminology is off;
     SunOS _IS_ the Kernel/OS.
     BSD _IS_ a Kernel -&- OS.
     (NT is _NOT_ an OS ;-).  
     NeXTOS is a Mach (a micro/mini-kernel) which runs a(some) process(es) that
     looks like BSD

   I believe the key point is that I could write a SysV like "process" that
   runs on Mach if I wanted (and had a bit more knowledge ;-)

   Somebody who knows more about NeXTOS and Mach can correct my terminology if
   needed.

Well, there has been occasional discussion on the net what
micro-kernel actually means, but I believe that most would agree that
the version of Mach used by NeXT does not fit any of them. There is
not actually any clear separation between a Mach micro-kernel which
runs a distinct "BSD process". Instead /mach seems to be compiled from
sources which freely mix both CMU Mach and BSD Unix. A superficial
examination of disassembled code seems to indicate that most of
the fundamental system services such as process or memory management
seem to be fairly pure Mach, while most of the rest like terminal
drivers or NFS seems to be compiled from BSD sources with a number of
interface routines added which implement BSD process or memory
management in terms of the equivalent Mach services.

        Carl Edman (not an actual computer scientist)