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DPRG: OS question.

Subject: DPRG: OS question.
From: J. Reeves Hall reeves at earthling.net
Date: Fri Feb 19 17:52:13 CST 1999

I have a casual interest in OS'es. I've toyed with my own microkernel (boots,
sets up flat-model protected mode, prints stuff on the screen, and halts). If
you do release it, I'd like to see it.

- -Reeves

Wade Maxfield wrote:

>   I have written a cooperative multitasking OS in C.  There is no assembly
> code to it.  Some assembly would be required to put it on an arbitrary
> cpu.
>   My question is this:  Would anyone on this list be interested in it?  I
> would be releasing it as GPL after a short period of clean up and trim
> down from its current deployment status.
> wade
> short description
>   It is a message based OS, with a crude memory manager (malloc() and
> free()).  You send tasks messages.
>   The tasks execute in round robin, with the ability to bypass the
> scheduler to execute immediately.  Each task is written as a normal
> function.  No fancy tricks.  The scheduler bypass makes use of this
> feature.
>   A timer task that sends messages a specified number of system clock
> ticks later also exists.
>   It is not perfect.  You would have to be careful to send messages to
> tasks from interrupts by using fixed memory. The message block freeing
> code ignores blocks not in its pool of memory.
>   On a 15 mhz 386EX, with the code compiled under Microsoft C compiler
> Version 1.52 in compact memory model (small code segment, large data
> segment), the average time to execute one bare bones task and switch to
> another is 400 micro seconds, all while it is servicing a 1 millisecond
> system time tick.
>   This code has been in testing and production for about a year.  I would
> have to trim things out to put into a more of a generic package.  I would
> be releaseing it under GPL.

- --
Before you criticize someone, walk a mile in their shoes.
That way, when you do criticize them, you'll be a mile away,
and you'll have their shoes.


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