1.\" 2.\" Copyright (c) 2007 3.\" The DragonFly Project. All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in 13.\" the documentation and/or other materials provided with the 14.\" distribution. 15.\" 3. Neither the name of The DragonFly Project nor the names of its 16.\" contributors may be used to endorse or promote products derived 17.\" from this software without specific, prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21.\" LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 22.\" FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 23.\" COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 24.\" INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 25.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 26.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 27.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 28.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 29.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" $DragonFly: src/share/man/man4/man4.i386/est.4,v 1.1 2007/12/21 09:00:41 swildner Exp $ 33.\" 34.Dd May 8, 2009 35.Os 36.Dt POWERNOW 4 37.Sh NAME 38.Nm powernow 39.Nd PowerNow! Technology support 40.Sh SYNOPSIS 41To compile this driver into the kernel, place the following line in your 42kernel configuration file: 43.Bd -ragged -offset indent 44.Cd "options CPU_ENABLE_POWERNOW" 45.Ed 46.Pp 47To load this driver as a module at boot time, place the following line in 48.Xr loader.conf 5 : 49.Bd -literal -offset indent 50powernow_load="YES" 51.Ed 52.Sh DESCRIPTION 53The 54.Nm 55driver provides support for the 56.Tn PowerNow! Technology 57present in AMD K8 CPUs. 58.Pp 59If the CPU is supported 60.Nm 61creates the following variables in the 62.Va machdep.powernow 63branch of the 64.Xr sysctl 3 65MIB. 66.Bl -tag -width ".Va frequency.available" -offset indent 67.It Va frequency.available 68(read only) The list of frequencies supported by 69.Nm 70for the CPU. 71.It Va frequency.current 72(read/write) The currect CPU frequency. 73.El 74.Pp 75.Sh HISTORY 76The 77.Nm 78driver first appeared in 79.Dx 2.3 . 80