15c335c81SXin LI.\" 25c335c81SXin LI.\"Copyright (c) 2010 iXsystems, Inc. 35c335c81SXin LI.\"All rights reserved. 45c335c81SXin LI.\" written by: Xin LI <delphij@FreeBSD.org> 55c335c81SXin LI.\" 65c335c81SXin LI.\"Redistribution and use in source and binary forms, with or without 75c335c81SXin LI.\"modification, are permitted provided that the following conditions 85c335c81SXin LI.\"are met: 95c335c81SXin LI.\"1. Redistributions of source code must retain the above copyright 105c335c81SXin LI.\" notice, this list of conditions and the following disclaimer. 115c335c81SXin LI.\"2. Redistributions in binary form must reproduce the above copyright 125c335c81SXin LI.\" notice, this list of conditions and the following disclaimer in the 135c335c81SXin LI.\" documentation and/or other materials provided with the distribution. 145c335c81SXin LI.\" 155c335c81SXin LI.\"THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 165c335c81SXin LI.\"ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 175c335c81SXin LI.\"IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 185c335c81SXin LI.\"ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 195c335c81SXin LI.\"FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 205c335c81SXin LI.\"DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 215c335c81SXin LI.\"OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 225c335c81SXin LI.\"HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 235c335c81SXin LI.\"LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 245c335c81SXin LI.\"OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 255c335c81SXin LI.\"SUCH DAMAGE. 265c335c81SXin LI.\" 275c335c81SXin LI.\" $FreeBSD$ 285c335c81SXin LI.\" 29c383d55bSGavin Atkinson.Dd February 8, 2010 30c383d55bSGavin Atkinson.Dt NVRAM 4 315c335c81SXin LI.Os 325c335c81SXin LI.Sh NAME 335c335c81SXin LI.Nm nvram 345c335c81SXin LI.Nd "non-volatile RAM" 355c335c81SXin LI.Sh SYNOPSIS 365c335c81SXin LITo compile this driver into the kernel, 375c335c81SXin LIplace the following line in your 385c335c81SXin LIkernel configuration file: 395c335c81SXin LI.Bd -ragged -offset indent 405c335c81SXin LI.Cd "device nvram" 415c335c81SXin LI.Ed 425c335c81SXin LI.Pp 435c335c81SXin LIAlternatively, to load the driver as a 445c335c81SXin LImodule at boot time, place the following line in 455c335c81SXin LI.Xr loader.conf 5 : 465c335c81SXin LI.Bd -literal -offset indent 475c335c81SXin LInvram_load="YES" 485c335c81SXin LI.Ed 495c335c81SXin LI.Sh DESCRIPTION 505c335c81SXin LIThe 515c335c81SXin LI.Nm 525c335c81SXin LIdriver provides access to BIOS configuration NVRAM on i386 and amd64 535c335c81SXin LIsystems. 545c335c81SXin LI.Pp 555c335c81SXin LIPC motherboard uses a small non-volatile memory to store BIOS settings 565c335c81SXin LIwhich is usually part of its clock chip and sometimes referred as 575c335c81SXin LI.Dq CMOS SRAM . 585c335c81SXin LIThis driver exposes bytes 14 through 128 of the NVRAM, or a total of 595c335c81SXin LI114 bytes, at offset zero of the device file 605c335c81SXin LI.Pa /dev/nvram . 615c335c81SXin LI.Pp 625c335c81SXin LIThis driver is useful for cloning machines that shares the same hardware 635c335c81SXin LIconfiguration and need same BIOS setting tweaks. 645c335c81SXin LI.Sh IMPLEMENTATION NOTES 655c335c81SXin LIThe BIOS NVRAM's bytes 16 through 31 are checksummed at byte 32. 665c335c81SXin LIThis driver 675c335c81SXin LI.Em does not 685c335c81SXin LItake care for these checksums. 695c335c81SXin LI.Sh EXAMPLES 705c335c81SXin LIBackup existing BIOS NVRAM to 715c335c81SXin LI.Pa nvram.bin : 725c335c81SXin LI.Pp 735c335c81SXin LI.Dl dd if=/dev/nvram of=nvram.bin 745c335c81SXin LI.Pp 755c335c81SXin LIRestore BIOS NVRAM from 765c335c81SXin LI.Pa nvram.bin : 775c335c81SXin LI.Pp 785c335c81SXin LI.Dl dd if=nvram.bin of=/dev/nvram 795c335c81SXin LI.Sh SEE ALSO 805c335c81SXin LI.Xr dd 1 815c335c81SXin LI.Sh HISTORY 825c335c81SXin LIThe 835c335c81SXin LI.Nm 845c335c81SXin LIdevice driver first appeared in 855c335c81SXin LI.Fx 6.4 . 865c335c81SXin LI.Sh AUTHORS 875c335c81SXin LI.An -nosplit 885c335c81SXin LIThe 895c335c81SXin LI.Nm 905c335c81SXin LIdevice driver was written by 915c335c81SXin LI.An Peter Wemm . 925c335c81SXin LIThis manual page was written by 935c335c81SXin LI.An Xin LI . 94