From owner-freebsd-mips@FreeBSD.ORG  Sat May  5 00:45:40 2007
Return-Path: <owner-freebsd-mips@FreeBSD.ORG>
X-Original-To: freebsd-mips@freebsd.org
Delivered-To: freebsd-mips@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
	by hub.freebsd.org (Postfix) with ESMTP id B206316A406
	for <freebsd-mips@freebsd.org>; Sat,  5 May 2007 00:45:40 +0000 (UTC)
	(envelope-from bms@incunabulum.net)
Received: from out1.smtp.messagingengine.com (out1.smtp.messagingengine.com
	[66.111.4.25]) by mx1.freebsd.org (Postfix) with ESMTP id 8DA6713C468
	for <freebsd-mips@freebsd.org>; Sat,  5 May 2007 00:45:40 +0000 (UTC)
	(envelope-from bms@incunabulum.net)
Received: from compute2.internal (compute2.internal [10.202.2.42])
	by out1.messagingengine.com (Postfix) with ESMTP id B765C21BF36
	for <freebsd-mips@freebsd.org>; Fri,  4 May 2007 20:45:50 -0400 (EDT)
Received: from heartbeat1.messagingengine.com ([10.202.2.160])
	by compute2.internal (MEProxy); Fri, 04 May 2007 20:45:40 -0400
X-Sasl-enc: moyFfvPc8sSd95tec1MjdrEKeWv6XQ8UnyTOy4Rh8JIG 1178325940
Received: from [192.168.123.18]
	(82-35-112-254.cable.ubr07.dals.blueyonder.co.uk [82.35.112.254])
	by mail.messagingengine.com (Postfix) with ESMTP id 7FE901CDBA
	for <freebsd-mips@freebsd.org>; Fri,  4 May 2007 20:45:40 -0400 (EDT)
Message-ID: <463BD3B2.9050903@incunabulum.net>
Date: Sat, 05 May 2007 01:45:38 +0100
From: Bruce M Simpson <bms@incunabulum.net>
User-Agent: Thunderbird 1.5.0.10 (X11/20070407)
MIME-Version: 1.0
To: freebsd-mips@freebsd.org
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Clock frequency, gxemul, yamon
X-BeenThere: freebsd-mips@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Porting FreeBSD to MIPS <freebsd-mips.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-mips>,
	<mailto:freebsd-mips-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-mips>
List-Post: <mailto:freebsd-mips@freebsd.org>
List-Help: <mailto:freebsd-mips-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-mips>,
	<mailto:freebsd-mips-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 05 May 2007 00:45:40 -0000

The tick.c code currently uses the CPU clock frequency (if known) for 
calibrating DELAY() and the MIPS on chip ticker, implemented using the 
cycle count register, a bit like TSC on x86.

It appears that the YAMON monitor includes a function to discover the 
clock frequency from the platform firmware.(I don't see a way to do this 
for CFE firmware).

GXemul's yamon shim does not support this function, a patch should be 
quite trivial to implement.

Regards,
BMS