IPXE
Encyclopedia
iPXE is an open-source Preboot Execution Environment
(PXE) implementation and bootloader. It can be used to enable computers without built-in PXE support to boot from the network, or to extend an existing PXE implementation with support for additional protocols. While traditional PXE clients use TFTP
to transfer data, iPXE adds the ability to retrieve data through other protocols like HTTP
, iSCSI
, ATA over Ethernet
(AoE), and Fibre Channel over Ethernet
(FCoE), and can work with Wi-Fi
rather than requiring a wired connection.
iPXE implements its own PXE stack, using a driver corresponding to the network card, or a UNDI
driver if it was loaded by PXE itself. This allows to use a PXE stack even if the network card has no boot ROM
, by loading iPXE from a fixed medium.
, and can boot PXE, ELF, Linux, FreeBSD
, multiboot
, EFI
and Windows CE
images.
In addition, it is scriptable and can load COMBOOT and COM32 SYSLINUX
extensions. This allows for instance to build a graphical menu for network boot.
Preboot Execution Environment
The Preboot eXecution Environment is an environment to boot computers using a network interface independently of data storage devices or installed operating systems.PXE was introduced as part of the Wired for Management framework by Intel and is described in the specification The Preboot...
(PXE) implementation and bootloader. It can be used to enable computers without built-in PXE support to boot from the network, or to extend an existing PXE implementation with support for additional protocols. While traditional PXE clients use TFTP
Trivial File Transfer Protocol
Trivial File Transfer Protocol is a file transfer protocol known for its simplicity. It is generally used forautomated transfer of configuration or boot files between machines in a local environment....
to transfer data, iPXE adds the ability to retrieve data through other protocols like HTTP
Hypertext Transfer Protocol
The Hypertext Transfer Protocol is a networking protocol for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web....
, iSCSI
ISCSI
In computing, iSCSI , is an abbreviation of Internet Small Computer System Interface, an Internet Protocol -based storage networking standard for linking data storage facilities. By carrying SCSI commands over IP networks, iSCSI is used to facilitate data transfers over intranets and to manage...
, ATA over Ethernet
ATA over Ethernet
ATA over Ethernet is a network protocol developed by the Brantley Coile Company, designed for simple, high-performance access of SATA storage devices over Ethernet networks. It is used to build storage area networks with low-cost, standard technologies.- Protocol description :AoE runs on layer 2...
(AoE), and Fibre Channel over Ethernet
Fibre Channel over Ethernet
Fibre Channel over Ethernet is an encapsulation of Fibre Channel frames over Ethernet networks. This allows Fibre Channel to use 10 Gigabit Ethernet networks while preserving the Fibre Channel protocol...
(FCoE), and can work with Wi-Fi
Wi-Fi
Wi-Fi or Wifi, is a mechanism for wirelessly connecting electronic devices. A device enabled with Wi-Fi, such as a personal computer, video game console, smartphone, or digital audio player, can connect to the Internet via a wireless network access point. An access point has a range of about 20...
rather than requiring a wired connection.
PXE implementation
iPXE can be loaded by a computer in several ways:- from media like floppy diskFloppy diskA floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles...
, USB flash driveUSB flash driveA flash drive is a data storage device that consists of flash memory with an integrated Universal Serial Bus interface. flash drives are typically removable and rewritable, and physically much smaller than a floppy disk. Most weigh less than 30 g...
, or hard disk - as a pseudo Linux kernelLinux kernelThe Linux kernel is an operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software....
- as an ELF imageExecutable and Linkable FormatIn computing, the Executable and Linkable Format is a common standard file format for executables, object code, shared libraries, and core dumps. First published in the System V Application Binary Interface specification, and later in the Tool Interface Standard, it was quickly accepted among...
- from an option ROMOption ROMAn Option ROM typically consists of firmware that is called by the system BIOS. For example, an adapter card that controls a boot device might contain firmware that is used to connect the device to the system once the Option ROM is loaded....
on a network card or embedded in a system BIOSBIOSIn IBM PC compatible computers, the basic input/output system , also known as the System BIOS or ROM BIOS , is a de facto standard defining a firmware interface.... - over a networkEthernetEthernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
as a PXE boot image
iPXE implements its own PXE stack, using a driver corresponding to the network card, or a UNDI
Universal Network Device Interface
Universal Network Device Interface is an application programming interface for network interface cards used by the Preboot Execution Environment protocol.-See also:* Network Driver Interface Specification...
driver if it was loaded by PXE itself. This allows to use a PXE stack even if the network card has no boot ROM
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...
, by loading iPXE from a fixed medium.
Bootloader
Although its basic role was to implement a PXE stack, iPXE can be used as a full-featured network bootloader. It can fetch files from multiple network protocols , such as TFTP, NFS, HTTP or FTPFile Transfer Protocol
File Transfer Protocol is a standard network protocol used to transfer files from one host to another host over a TCP-based network, such as the Internet. FTP is built on a client-server architecture and utilizes separate control and data connections between the client and server...
, and can boot PXE, ELF, Linux, FreeBSD
FreeBSD
FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...
, multiboot
Multiboot Specification
The Multiboot Specification is an open standard originally created in 1995 and developed by the Free Software Foundation. The specification describes a method of loading various multiboot kernels using a single compliant boot loader. GNU Hurd, VMware ESXi, Xen, and L4 microkernels all need to be...
, EFI
Extensible Firmware Interface
The Unified Extensible Firmware Interface is a specification that defines a software interface between an operating system and platform firmware...
and Windows CE
Windows CE
Microsoft Windows CE is an operating system developed by Microsoft for embedded systems. Windows CE is a distinct operating system and kernel, rather than a trimmed-down version of desktop Windows...
images.
In addition, it is scriptable and can load COMBOOT and COM32 SYSLINUX
SYSLINUX
The SYSLINUX Project is a suite of lightweight IBM PC MBR bootloaders for starting up computers with the Linux kernel. It is the work of H. Peter Anvin, and consists of several separate systems, the best-known of which is ISOLINUX.-List:...
extensions. This allows for instance to build a graphical menu for network boot.