From owner-freebsd-hackers  Sun Nov 30 11:02:47 1997
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From: jak@cetlink.net (John Kelly)
To: John-Mark Gurney <gurney_j@resnet.uoregon.edu>
Cc: hackers@freebsd.org
Subject: Re: 650 UART, SIO driver, 8259 PIC
Date: Sun, 30 Nov 1997 20:03:34 GMT
Message-ID: <3483bf52.19369575@mail.cetlink.net>
References: <199711300856.TAA05947@godzilla.zeta.org.au> <19971130011359.25067@hydrogen.nike.efn.org>
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On Sun, 30 Nov 1997 01:13:59 -0800, John-Mark Gurney
<gurney_j@efn.org> wrote:

>personally, I would like to see a complete rewrite of most of the hardware
>into two layers, the "chip interface" layer which describes how the
>chip interacts, and then a bus layer in how the chip is mapped to the
>computer..

Abstraction creates inefficiencies which can be avoided in a
monolithic design.  And the interdependence of the SIO code with the
peculiarities of the Intel PC interrupt architecture would be
difficult to abstract without creating subtle or hidden flaws.

John