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From: deraadt@fsa.ca (Theo de Raadt)
Newsgroups: comp.os.386bsd.questions
Subject: Re: more NetBSD questions
Date: 16 Dec 93 08:53:41
Organization: little lizard city
Lines: 45
Message-ID: <DERAADT.93Dec16085341@newt.fsa.ca>
References: <9335018.1085@mulga.cs.mu.OZ.AU> <2ept1l$es1@fs7.ece.cmu.edu>
NNTP-Posting-Host: newt.fsa.ca
In-reply-to: adean@spitz.ece.cmu.edu's message of 16 Dec 1993 14:57:57 GMT
In article <2ept1l$es1@fs7.ece.cmu.edu> adean@spitz.ece.cmu.edu (Alexander G. Dean) writes:
1. Does the base install of NetBSD-0.9 automatically sense and use the
387 coprocessor in my NetBSD machine?
Yes. Here's the latest version of the man page:
NPX(4) NetBSD Programmer's Manual NPX(4)
NAME
npx - Numeric Processing Extension coprocessor and emulator
SYNOPSIS
options MATH_EMULATE
device npx0 at isa? port "IO_NPX0" tty irq 13 vector npxintr
DESCRIPTION
The npx driver enables the use of the system's Numeric Processing Exten-
sion coprocessor, if one is present. Numeric processing extensions are
present in systems with 486DX CPUs and in systems with 387 or 487SX co-
processors. The npx driver is required for proper system functioning re-
gardless of whether or not a NPX is present.
If there is no NPX present in the system, the "MATH_EMULATE" option must
be defined in the kernel configuration file. It will provide support for
the instructions normally executed by the NPX. If there is no NPX in the
system and the kernel is not built with math emulation, the system will
not boot.
CAVEATS
The emulator is much slower than the NPX coprocessor. This will result
in poor floating-point math performance if the emulator must be used.
BUGS
There are lots of them, especially on cheap motherboards. In particular,
some motherboards do not have the interrupt lines from the NPX to the CPU
wired properly. If this is the case, the emulator must be used if con-
sistent system operation is desired.
Emulation of the transcendental functions instructions is incorrect. Em-
ulation of other instructions is suspect.
NetBSD 0.8a December 2, 1993 1
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