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PXEBOOT(8) System Manager's Manual PXEBOOT(8) NAME pxeboot -- Preboot Execution Environment (PXE) bootloader DESCRIPTION The pxeboot bootloader is a modified version of the system third-stage bootstrap loader(8) configured to run under Intel's Preboot Execution Envi- ronment (PXE) system. PXE is a form of smart boot ROM, built into Intel EtherExpress Pro/100 and 3Com 3c905c Ethernet cards, and Ethernet-equipped Intel motherboards. PXE supports DHCP configuration and provides low-level NIC access services. The DHCP client will set a DHCP user class named FreeBSD to allow flexible configuration of the DHCP server. The pxeboot bootloader retrieves the kernel, modules, and other files ei- ther via NFS over UDP or by TFTP, selectable through compile-time options. In combination with a memory file system image or NFS-mounted root file system, pxeboot allows for easy, EEPROM-burner free construction of disk- less machines. The pxeboot binary is loaded just like any other boot file, by specifying it in the DHCP server's configuration file. Below is a sample configura- tion for the ISC DHCP v3 server: 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; if exists user-class and option user-class = "FreeBSD" { option root-path "tftp://10.0.0.1/FreeBSD"; } } next-server is the IP address of the next server in the bootstrap process, i.e. your TFTP server or NFS server. pxeboot recognizes option root-path directives as the server and path to NFS mount for file requests, respec- tively, or the server to make TFTP requests to. Note that pxeboot expects to fetch /boot/loader.rc from the specified server before loading any other files. Valid option root-path syntax is the following /path path to the root filesystem on the NFS server ip://path path to the root filesystem on the NFS server ip nfs://path path to the root filesystem on the NFS server nfs://ip/path path to the root filesystem on the NFS server ip tftp://path path to the root filesystem on the TFTP server tftp://ip/path path to the root filesystem on the TFTP server ip pxeboot defaults to a conservative 1024 byte NFS data packet size. This may be changed by setting the nfs.read_size variable in /boot/loader.conf. Valid values range from 1024 to 16384 bytes. In all other respects, pxeboot acts just like loader(8). For further information on Intel's PXE specifications and Wired for Manage- ment (WfM) systems, see http://www.pix.net/software/pxeboot/archive/pxespec.pdf. SEE ALSO loader(8) HISTORY The pxeboot bootloader first appeared in FreeBSD 4.1. AUTHORS The pxeboot bootloader was written by John Baldwin <jhb@FreeBSD.org> and Paul Saab <ps@FreeBSD.org>. This manual page was written by Doug White <dwhite@FreeBSD.org>. FreeBSD ports 15.1 February 15, 2021 PXEBOOT(8)
NAME | DESCRIPTION | SEE ALSO | HISTORY | AUTHORS
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