Core boot

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coreboot

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Basic data

developer Coreboot team
Publishing year 1999
Current  version 4.11
(November 19, 2019)
operating system supports various operating systems
programming language C , assembly language
category hardware-related software
License GPLv2 ( free software )
coreboot.org

Coreboot ( own spelling : coreboot, formerly LinuxBIOS ) is a project which aims to develop an open source, free BIOS . LinuxBIOS was started in 1999 by Los Alamos National Laboratory and renamed "coreboot" in early 2008. The project is licensed under the GNU General Public License .

The project is endorsed by the Free Software Foundation (FSF) and is considered one of the high priority projects. The project also received support from industry , for example from Google , MSI , Silicon Integrated Systems (SiS), Tyan , Linux Networx and coresystems GmbH , and at times also from AMD .

Innovations in core boot

The boot process can be considerably accelerated by using Coreboot. On some systems the boot time is less than a second. Furthermore, Coreboot allows remote access and is specially designed for cluster systems.

Function for the boot process

Coreboot itself is just a minimal code to start the mainboard with all its devices. Immediately thereafter, there is a transfer to a so-called payload, which then continues to start up the system. Coreboot itself does not contain a kernel . A large part of the core boot code is used to make the RAM usable, to initialize the PCI bus and the serial interface, the latter as an output device for troubleshooting.

After the system initialization by Coreboot, the payload starts up and takes over the further startup of the system. The best known are FILO (a minimalist bootloader ), Etherboot , an IEEE 1275-compliant Open Firmware implementation (this includes OpenBIOS , SmartFirmware and Open Firmware itself), Memtest86 , GRUB2 , SeaBIOS , Plan 9 and a Linux kernel . In principle, various other bootloaders, operating systems and standalone software can also be used as payloads.

From version 2.6 the Linux kernel is so large (> 1  MiB ) that it cannot be accommodated in most common flash ROMs (4 Mbit or 512  KiB ). Since Coreboot does not contain any device drivers, the hard disk cannot be read directly and a payload with device drivers (e.g. FILO or GRUB2) takes over the loading from the hard disk. Since newer mainboards often use flash ROMs that are soldered on, replacing them with larger chips is not always practical. The largest available Flash ROMs are in the order of 4 to 8 MiB, which is even sufficient for a complete Linux distribution with a graphical user interface.

Supported hardware

Hardware support is divided into motherboard support and chipset support .

Currently, a total of around 230 motherboards from different manufacturers (with many different chipsets) are supported.

All Chromebooks except the first three models run with Coreboot.

Use of Coreboot

Coreboot is used in various cluster systems, including at the Los Alamos National Laboratory, and also in various embedded systems (e.g. in set-top boxes ). Another area of ​​application is the server area. For example, the Free Software Foundation uses several servers with a core boot (and above that a free operating system). Support for standard desktop computer is given: the Gigabyte GA-M57SLI-S4, a mainstream - AM2 - Mainboard example, is supported.

Importance to the free software movement

The GNU project , founded in 1983 , initially aimed to develop a free operating system . Together with Linux , which was placed under the GPL in 1992 , the first operating system was created that was available under an open source license - apart from the proprietary firmware that was active before the operating system was started . The problem of this missing piece of Free Software was not addressed until 1999. By using core boot in connection with a free ROM image (for example a Linux kernel, OpenBIOS, Open Firmware, etc.), a more or less free bridge between hardware and software was built. Coreboot still contains proprietary binary blobs , which is why a distribution of Coreboot called Libreboot was founded in the summer of 2014 .

Conventional BIOS variants are often afflicted with certain software errors; these often cannot be corrected unless an update is made available by the manufacturer. In addition to these unintentional restrictions, there are approaches to implement further functions in the proprietary firmware (BIOS or UEFI ) in the future, which raise concerns about conscious restrictions in functionality. For example, digital rights management , the functionality of which is deliberately not disclosed in parts.

Web links

Individual evidence

  1. ↑ Pro-Linux News: LinuxBIOS becomes Coreboot
  2. ↑ See http://www.fsf.org/campaigns/priority.html#coreboot
  3. ↑ See listing on the Coreboot Wiki
  4. ↑ LinuxBIOS with X Server Inside
  5. ↑ Coreboot Wiki
  6. ↑ Archived copy ( Memento of the original from May 8, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.coreboot.org
  7. ↑ Libreboot ( English ) Free Software Foundation. Retrieved February 10, 2017.
  8. ↑ Libreboot ( English ) Libreboot. Retrieved February 10, 2017.