PXEBOOT(8) OpenBSD System Manager's Manual (i386) PXEBOOT(8)NAMEpxeboot - i386-specific second-stage PXE bootstrap
DESCRIPTIONpxeboot is a modified version of the i386 second-stage bootstrap program,
boot(8), configured to run under Intel's Preboot Execution Environment
(PXE). PXE is a form of smart boot ROM, built into many Ethernet cards
from Intel, 3Com, and other manufacturers.
The computer's PXE boot ROM contacts a DHCP server by broadcasting a
request on the network. It gets an IP address from the DHCP server, then
it is told the name of the boot program to download -- in this case, the
boot program is pxeboot. The ROM downloads the boot program using TFTP,
then executes it.
The pxeboot boot program will look for an /etc/boot.conf configuration
file on the TFTP server. If it finds one, it processes the commands
within it. boot.conf processing can be skipped by holding down either
Control key as pxeboot starts.
pxeboot then sits in a loop, processing commands given by the user. It
accepts all the commands accepted by boot(8).
If no commands are given for a short time, pxeboot will then attempt to
load the OpenBSD kernel bsd via TFTP. It may be told to boot an
alternative kernel, either by commands in the boot.conf file, or by
commands typed by the user at the boot> prompt. pxeboot can be used for
diskless(8) setups or to load the bsd.rd install kernel for network
installs.
To prepare a server to support network booting, the dhcpd(8) and tftpd(8)
services should be enabled and configured. It may help to use the -s
option with tftpd(8), to avoid confusion between files for the server's
system and files for the client system (note that -s is set by default in
OpenBSD). ftpd(8) or httpd(8) should be enabled, depending on how the
install sets will be made available.
pxeboot and the kernel should be copied into the TFTP server's root
directory (typically /tftpboot). A boot.conf file may be created if
required (e.g. /tftpboot/etc/boot.conf).
A sample configuration file for dhcpd(8) might be as follows:
option domain-name "example.com";
option routers 10.0.0.1;
option subnet-mask 255.255.255.0;
option broadcast-address 10.0.0.255;
option domain-name-servers 10.0.0.1;
server-name "DHCPserver";
server-identifier 10.0.0.1;
next-server 10.0.0.1;
default-lease-time 120;
max-lease-time 120;
subnet 10.0.0.0 netmask 255.255.255.0 {
filename "pxeboot";
range 10.0.0.10 10.0.0.254;
}
See dhcpd(8) and dhcpd.conf(5) for more information.
FILES
/usr/mdec/pxeboot PXE-specific second-stage bootstrap
/etc/boot.conf pxeboot configuration file (read from TFTP server)
/etc/dhcpd.conf DHCPD configuration file
/tftpboot Default root directory for tftpd(8)EXAMPLES
Boot the install kernel:
boot> bsd.rd
The same thing:
boot> boot tftp:bsd.rd
SEE ALSOdhcpd.conf(5), boot(8), boot_i386(8), dhcpd(8), diskless(8), httpd(8),
tftpd(8)
Intel Corporation, Preboot Execution Environment (PXE) Specification,
Version 2.1, September 20, 1999.
HISTORY
The pxeboot command first appeared in OpenBSD 3.5.
OpenBSD 4.9 January 16, 2009 OpenBSD 4.9