1.\" Copyright (c) 1999 Doug White 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd May 27, 2017 28.Dt PXEBOOT 8 29.Os 30.Sh NAME 31.Nm pxeboot 32.Nd Preboot Execution Environment (PXE) bootloader 33.Sh DESCRIPTION 34The 35.Nm 36bootloader is a modified version of the system third-stage bootstrap 37.Xr loader 8 38configured to run under Intel's Preboot Execution Environment (PXE) system. 39PXE is a form of smart boot ROM, built into Intel EtherExpress Pro/100 and 403Com 3c905c Ethernet cards, and Ethernet-equipped Intel motherboards. 41PXE supports DHCP configuration and provides low-level NIC access services. 42.Pp 43The DHCP client will set a DHCP user class named 44.Va FreeBSD 45to allow flexible configuration of the DHCP server. 46.Pp 47The 48.Nm 49bootloader retrieves the kernel, modules, 50and other files either via NFS over UDP or by TFTP, 51selectable through compile-time options. 52In combination with a memory file system image or NFS-mounted root file system, 53.Nm 54allows for easy, 55EEPROM-burner free construction of diskless machines. 56.Pp 57The 58.Nm 59binary is loaded just like any other boot file, 60by specifying it in the DHCP server's configuration file. 61Below is a sample configuration for the ISC DHCP v2 server: 62.Bd -literal -offset indent 63option domain-name "example.com"; 64option routers 10.0.0.1; 65option subnet-mask 255.255.255.0; 66option broadcast-address 10.0.0.255; 67option domain-name-servers 10.0.0.1; 68server-name "DHCPserver"; 69server-identifier 10.0.0.1; 70 71default-lease-time 120; 72max-lease-time 120; 73 74subnet 10.0.0.0 netmask 255.255.255.0 { 75 filename "pxeboot"; 76 range 10.0.0.10 10.0.0.254; 77 if exists user-class and option user-class = "FreeBSD" { 78 option root-path "tftp://10.0.0.1/FreeBSD"; 79 } 80} 81 82.Ed 83.Nm 84recognizes 85.Va next-server 86and 87.Va option root-path 88directives as the server and path to NFS mount for file requests, 89respectively, or the server to make TFTP requests to. 90Note that 91.Nm 92expects to fetch 93.Pa /boot/loader.rc 94from the specified server before loading any other files. 95.Pp 96Valid 97.Va option root-path 98Syntax is the following 99.Bl -tag -width <scheme>://ip/path indent 100.It /path 101path to the root filesystem on the NFS server 102.It ip:/path 103path to the root filesystem on the NFS server 104.Ar ip 105.It nfs:/path 106path to the root filesystem on the NFS server 107.It nfs://ip/path 108path to the root filesystem on the NFS server 109.Ar ip 110.It tftp:/path 111path to the root filesystem on the TFTP server 112.It tftp://ip/path 113path to the root filesystem on the TFTP server 114.Ar ip 115.El 116.Pp 117.Nm 118defaults to a conservative 1024 byte NFS data packet size. 119This may be changed by setting the 120.Va nfs.read_size 121variable in 122.Pa /boot/loader.conf . 123Valid values range from 1024 to 16384 bytes. 124.Pp 125In all other respects, 126.Nm 127acts just like 128.Xr loader 8 . 129.Pp 130As PXE is still in its infancy, some firmware versions may not work 131properly. 132The 133.Nm 134bootloader has been extensively tested on version 0.99 of Intel firmware; 135pre-release versions of the newer 2.0 firmware are known to have 136problems. 137Check with the device's manufacturer for their latest stable release. 138.Pp 139For further information on Intel's PXE specifications and Wired for 140Management (WfM) systems, see 141.Li http://www.intel.com/design/archives/wfm/ . 142.Sh SEE ALSO 143.Xr loader 8 144.Sh HISTORY 145The 146.Nm 147bootloader first appeared in 148.Fx 4.1 . 149.Sh AUTHORS 150.An -nosplit 151The 152.Nm 153bootloader was written by 154.An John Baldwin Aq jhb@FreeBSD.org 155and 156.An Paul Saab Aq ps@FreeBSD.org . 157This manual page was written by 158.An Doug White Aq dwhite@FreeBSD.org . 159