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: src/sys/boot/i386/pxeldr/pxeboot.8,v 1.7 2002/12/12 17:25:59 ru Exp $ 26.\" 27.Dd November 1, 2019 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. 42The 43.Nm 44bootloader retrieves the kernel, modules, 45and other files either via NFS over UDP. 46In combination with a NFS-mounted root file system, 47.Nm 48allows for easy, 49EEPROM-burner free construction of diskless machines. 50.Pp 51The 52.Nm 53binary is loaded just like any other boot file, 54by specifying it in the DHCP server's configuration file. 55Below is a sample configuration for the ISC DHCP v2 server: 56.Bd -literal -offset indent 57option domain-name "example.com"; 58option routers 10.0.0.1; 59option subnet-mask 255.255.255.0; 60option broadcast-address 10.0.0.255; 61option domain-name-servers 10.0.0.1; 62server-name "DHCPserver"; 63server-identifier 10.0.0.1; 64 65default-lease-time 120; 66max-lease-time 120; 67 68subnet 10.0.0.0 netmask 255.255.255.0 { 69 filename "boot/pxeboot"; 70 range 10.0.0.10 10.0.0.254; 71 option root-path "10.0.0.1:/netbootroot"; 72} 73 74.Ed 75.Nm 76defaults to a conservative 1024 byte NFS data packet. 77This may be changed by setting the 78.Va nfs.read_size 79variable in 80.Pa /boot/loader.conf . 81Valid values range from 1024 to 4096 bytes. 82.Pp 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/dloader.rc 94from the specified server before loading any other files. 95.Pp 96.Nm 97uses 98.Pa /boot/kernel.BOOTP 99and 100.Pa /boot/loader-bootp.conf 101instead of 102.Pa /boot/kernel 103and 104.Pa /boot/loader.conf . 105Note that the TFTP version 106.Xr pxeboot_tftp 8 107uses the standard boot loader files. 108The NFS version uses different files to allow BOOTP boots via NFS to 109be overloaded onto the same directory structure as a normal boot, 110though many other changes would have to be made to actually make 111that work. 112However, this is more for historical reasons. 113Current day PXE boot code can handle complex root-path specifications 114allowing the root image to be contained in a sub-directory of the NFS 115export. 116.Pp 117In all other respects, 118.Nm 119acts just like 120.Xr loader 8 . 121.Pp 122As PXE is still in its infancy, some firmware versions may not work 123properly. 124The 125.Nm 126bootloader has been extensively tested on version 0.99 of Intel firmware; 127pre-release versions of the newer 2.0 firmware are known to have 128problems. 129Check with the device's manufacturer for their latest stable release. 130.Pp 131For further information on Intel's PXE specifications and Wired for 132Management (WfM) systems, see 133.Pa http://developer.intel.com/ial/wfm/ . 134.Sh FILES 135.Bl -tag -width ".Pa /boot/defaults/loader-bootp.conf" -compact 136.It Pa /boot/kernel.BOOTP 137Default kernel for 138.Nm . 139.It Pa /boot/defaults/loader-bootp.conf 140.Nm 141configuration file -- do not change this file. 142.It Pa /boot/loader-bootp.conf 143.Nm 144configuration file. 145.El 146.Sh SEE ALSO 147.Xr dhcpd 8 Pq Pa net/isc-dhcp42-server , 148.Xr diskless 8 , 149.Xr loader 8 , 150.Xr nfsd 8 , 151.Xr pxeboot_tftp 8 , 152.Xr tftpd 8 153.Sh HISTORY 154The 155.Nm 156bootloader first appeared in 157.Fx 4.1 . 158.Sh AUTHORS 159.An -nosplit 160The 161.Nm 162bootloader was written by 163.An John Baldwin Aq Mt jhb@FreeBSD.org 164and 165.An Paul Saab Aq Mt ps@FreeBSD.org . 166This manual page was written by 167.An Doug White Aq Mt dwhite@FreeBSD.org . 168