Kernel Definition

[Barnacle Wes]

In article <greg.675107364 at travis>, greg at travis.cica.indiana.edu (Gregory TRAVIS) writes:
> Swapping out parts of the kernel was never part of the plan.  All of the
> code for the kernel, even if it was 300K, was locked into core from system
> startup to shutdown.  All in continguous memory.  Only the hardware
> segment registers were modified to bring the appropriate pieces of this
> code into the 64K "execution window."

This scheme should sound familiar to everyone reading this thread in
comp.unix.sysv286; it is similar to the way a 286 kernel is managed.  My
current (V/AT 2.3) kernel has 3 text segments.  The 286 doesn't have, or
need, the microkernel concept discussed earlier in Greg's post, but the
segment loading is very similar in concept.

> This overlay scheme was also used at the application level.  Big Emacs would
> have been impossible without it!  And it was almost completely transparent
> to the programmer.

Ditto for V/AT.  Just compile with -Ml to get multiple-segment programs.

	Wes Peters
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