PXEBOOT(8)              FreeBSD 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
     Environment (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
     either 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 diskless 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
     configuration 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, respectively, 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
     Management (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 13.1-RELEASE-p6        February 15, 2021       FreeBSD 13.1-RELEASE-p6