Coreboot

coreboot
Original author(s)Ronald G. Minnich, Eric Biederman, Li-Ta (Ollie) Lo, Stefan Reinauer, and the coreboot community
Initial release1999; 26 years ago (1999)
Stable release
24.08[1] Edit this on Wikidata / 2 September 2024; 3 months ago (2 September 2024)[2]
Repository
Written inMostly C, about 1% in assembly and optionally SPARK
PlatformIA-32, x86-64, ARMv7,[3] ARMv8, MIPS, RISC-V, POWER8
TypeFirmware
LicenseGPLv2-only[4]
Websitewww.coreboot.org Edit this on Wikidata

coreboot, formerly known as LinuxBIOS,[5] is a software project aimed at replacing proprietary firmware (BIOS or UEFI) found in most computers with a lightweight firmware designed to perform only the minimum number of tasks necessary to load and run a modern 32-bit or 64-bit operating system.

Since coreboot initializes the bare hardware, it must be ported to every chipset and motherboard that it supports. As a result, coreboot is available only for a limited number of hardware platforms and motherboard models.

One of the coreboot variants is Libreboot, a software distribution partly free of proprietary blobs, aimed at end users.

History

The coreboot project began with the goal of creating a BIOS that would start fast and handle errors intelligently.[6] It is licensed under the terms of the GNU General Public License version 2 (GPLv2). Main contributors include LANL, SiS, AMD, Coresystems and Linux Networx, Inc, as well as motherboard vendors MSI, Gigabyte and Tyan, which offer coreboot alongside their standard BIOS or provide specifications of the hardware interfaces for some of their motherboards. Google partly sponsors the coreboot project.[7] CME Group, a financial public company, began supporting the coreboot project in 2009.[8]

Other than the first three models, all Chromebooks run coreboot.[9] Code from Das U-Boot has been assimilated to enable support for processors based on the ARM instruction set.[10]

In June 2019, coreboot began to use the NSA software Ghidra for its reverse engineering efforts on firmware-specific problems following the release of the suite as free and open source software.[11]

Supported platforms

CPU architectures supported by coreboot include IA-32, x86-64, ARM, ARM64, MIPS and RISC-V. Supported system-on-a-chip (SOC) platforms include AMD Geode, starting with the Geode GX processor developed for the OLPC. Artec Group added Geode LX support for its ThinCan model DBE61; that code was adopted by AMD and further improved for the OLPC after it was upgraded to the Geode LX platform, and is further developed by the coreboot community to support other Geode variants. coreboot can be flashed onto a Geode platform using Flashrom.

From that initial development on AMD Geode based platforms, coreboot support has been extended onto many AMD processors and chipsets. The processor list includes Family 0Fh and 10h (K8 core), and recently Family 14h (Bobcat core, Fusion APU). coreboot support also extends to AMD chipsets: RS690, RS7xx, SB600, and SB8xx.

In AMD Generic Encapsulated Software Architecture (AGESA)‍—‌a bootstrap protocol by which system devices on AMD64 mainboards are initialized‍—‌was open sourced in early 2011, aiming to provide required functionality for coreboot system initialization on AMD64 hardware.[12] However, as of 2014 such releases never became the basis for future development by AMD, and were subsequently halted.[13]

Devices that could be preloaded with coreboot or one of its derivatives include:

Lenovo/IBM
The Libreboot T400 and X200 (rebranded ThinkPad T400 and X200, respectively, available from Minifree, previously known as Gluglug).[14][15]
Artec Group
ThinCan models DBE61, DBE62 and DBE63, and fanless server/router hardware manufactured by PC Engines.[16]
Purism
Librem laptops come with coreboot.[17][18]
Others
Some System76 PCs use coreboot TianoCore firmware, including open source Embedded Controller firmware.
Dasharo offers an alternative coreboot-based firmware distribution for computers from MSI, NovaCustom and Nitrokey, among others.[19][20][21]
StarLabs Systems use coreboot firmware, as an alternative.[22]

Design

Coreboot typically loads a Linux kernel, but it can load any other stand-alone ELF executable, such as iPXE, gPXE or Etherboot that can boot a Linux kernel over a network, or SeaBIOS[23] that can load a Linux kernel, Windows 2000 and later, and BSDs; Windows 2000/XP and OpenBSD support was previously provided by ADLO.[24][25] coreboot can also load a kernel from any supported device, such as Myrinet, Quadrics, or SCI cluster interconnects. Booting other kernels directly is also possible, such as a Plan 9 kernel. Instead of loading a kernel directly, coreboot can pass control to a dedicated boot loader, such as a coreboot-capable version of GNU GRUB 2.

Coreboot is written primarily in C, with a small amount of assembly code. Choosing C as the primary programming language enables easier code audits when compared to contemporary PC BIOS that was generally written in assembly,[26] which results in improved security. There is build and runtime support to write parts of coreboot in Ada[27] to further raise the security bar, but it is currently only sporadically used. The source code is released under the GNU GPL version 2 license.

Coreboot performs the absolute minimal amount of hardware initialization and then passes control to the operating system. As a result, there is no coreboot code running once the operating system has taken control. A feature of coreboot is that the x86 version runs in 32-bit mode after executing only ten instructions[28] (almost all other x86 BIOSes run exclusively in 16-bit mode). This is similar to the modern UEFI firmware, which is used on newer PC hardware.

Initializing DRAM

The most difficult hardware that coreboot initializes is the DRAM controllers and DRAM. In some cases, technical documentation on this subject is NDA restricted or unavailable. RAM initialization is particularly difficult because before the RAM is initialized it cannot be used. Therefore, to initialize DRAM controllers and DRAM, the initialization code may have only the CPU's general purpose registers or Cache-as-RAM as temporary storage.

romcc, a C compiler that uses registers instead of RAM, eases the task. Using romcc, it is relatively easy to make SMBus accesses to the SPD ROMs of the DRAM DIMMs, that allows the RAM to be used.

With newer x86 processors, the processor cache can be used as RAM until DRAM is initialized. The processor cache has to be initialized into Cache-as-RAM[29][30] mode as well, but this needs fewer instructions than initializing DRAM. Also, the Cache-as-RAM mode initialization is specific to CPU architectures, thus more generic than DRAM initialization, which is specific to each chipset and mainboard.

For most modern x86 platforms, closed source binary-only components provided by the vendor are used for DRAM setup. For Intel systems, FSP-M is required, while AMD has no current support. Binary AGESA is currently used for proprietary UEFI firmware on AMD systems, and this model is expected to carry over to any future AMD-related coreboot support.[31]

Developing and debugging coreboot

Hacking coreboot at Denver 2008 summit.

There are also CPU emulators that either replace the CPU or connect via a JTAG port, with the Sage SmartProbe[32][33] being an example. Code can be built on, or downloaded to, BIOS emulators rather than flashing the BIOS device.

Payloads

SeaBIOS payload running on a Lenovo ThinkPad X60

coreboot can load a payload, which may be written using the libpayload helper library. Existing payloads include the following:

European Coreboot Conference

One physical meeting is the European Coreboot Conference which was organized in October 2017 and lasted for three days.

Conference history

Event and year Date Host city Venue Resources Themes
ECC2017 26.10. – 29.10 Bochum, Germany RUB Convention Center https://ecc2017.com

Variants

coreboot has a number of variants from its original code base each with slightly different objectives:.

  • Libreboot - A variant with a primary focus to remove some[36] binary blobs.
  • osboot - A variant similar to Libreboot that scrapped its only some blobs policy to increase hardware support and stability.[37] Merged with libreboot as of November 2022.[38]
  • MrChromebox has developed a modified version of coreboot for ChromeOS based devices.[39]
  • GNU Boot - A variant with a primary focus to remove all binary blobs.[40]
  • Canoeboot[41]
  • Dasharo - A distribution based on coreboot developed by 3mdeb.[42] They aim to make it easy for manufacturers to ship products with coreboot.[43][44]
  • Skulls - A variant aimed at ease of installation.[45]
  • Heads - A variant aimed at physical security and usage of free software, recommended for use with QubesOS.[46][47][citation needed]

See also

References

  1. ^ Martin Roth (2 September 2024). "coreboot 24.08 release". Retrieved 3 September 2024.
  2. ^ "Releases". coreboot. n.d.
  3. ^ "ARM". coreboot. 15 October 2013. Retrieved 1 February 2014.
  4. ^ "coreboot's licence". github.com. 1991. Retrieved 13 October 2018.
  5. ^ "[LinuxBIOS] Welcome to coreboot". 12 January 2008.
  6. ^ Anton Borisov (2009). "The Open Source BIOS is Ten. An interview with the coreboot developers". The H. Archived from the original on 16 September 2012.'
  7. ^ "Google Sponsors the LinuxBIOS project". Archived from the original on 6 February 2012. Retrieved 29 September 2023.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
  8. ^ "CME Group Dives Into Coreboot and Other Linux Open Source Projects". Wall Street & Technology. Archived from the original on 12 August 2010. Retrieved 23 September 2015.
  9. ^ "Chromebooks". coreboot. 16 January 2014. Archived from the original on 8 May 2016. Retrieved 17 February 2014.
  10. ^ "GSoC2011(Week 1): Analysis of U-boot ARM boot code | coreboot developer blogs". 5 June 2011. Retrieved 12 April 2014.
  11. ^ "Coreboot nutzt NSA-Tool zum Reverse Engineering". Golem.de. Retrieved 4 May 2023.
  12. ^ "Technical details on AMD's coreboot source code release". AMD. 28 February 2011. Archived from the original on 25 March 2014. Retrieved 1 February 2016.
  13. ^ Griffith, Bruce (5 November 2014). "AMD's binary-only AGESA libraries". Retrieved 8 May 2017.
  14. ^ "Minifree". Ministry of Freedom - Products. Archived from the original on 25 September 2015. Retrieved 24 September 2015.
  15. ^ "The Gluglug". fsf.org. Archived from the original on 23 September 2015. Retrieved 23 September 2015.
  16. ^ "pcengines/coreboot". GitHub. Retrieved 16 September 2019.
  17. ^ "coreboot Firmware on Purism Librem devices". Retrieved 19 June 2020.
  18. ^ "Purism Laptops To Use 'Heads' Firmware To Protect Against Rootkits, Tampering (Updated)". 27 February 2018. Retrieved 19 June 2020.
  19. ^ "New Dasharo v1.1 Firmware For The MSI Z690 Board - Phoronix". 22 November 2022. Retrieved 27 October 2023.
  20. ^ "NovaCustom-Dasharo October-2023 Firmware Update (ADL v1.7.0 & TGL v1.5.0) - NovaCustom". 19 September 2023. Retrieved 27 October 2023.
  21. ^ "The NitroPC Pro is Qubes-Certified! - Nitrokey". 24 September 2023. Retrieved 27 October 2023.
  22. ^ Starbook mk v review - fossbytes
  23. ^ SeaBIOS (previously known as LegacyBIOS) is an open-source legacy BIOS implementation
  24. ^ "coreboot Add-on Layer (ADLO)". Archived from the original on 25 November 2010.
  25. ^ "SEBOS, Security Enhanced Bootloader for Operating Systems, Phase 2". Archived from the original on 19 June 2007. - adding PC BIOS Services to coreboot via Bochs BIOS
  26. ^ "Comparison of UEFI and legacy BIOS". pronouncing that same advantage for UEFI
  27. ^ "commit". adding that support
  28. ^ "coreboot v3 early startup code". Archived from the original on 10 July 2012. Retrieved 17 August 2008.
  29. ^ Yinghai Lu; Li-Ta Lo; Gregory R. Watson; Ronald G. Minnich (15 January 2009). "CAR: Using Cache as RAM in Linux BIOS" (PDF). qmqm.pl. Archived from the original (PDF) on 3 March 2016. Retrieved 25 February 2014.
  30. ^ "A Framework for Using Processor Cache as RAM (CAR)" (PDF).
  31. ^ Griffith, Bruce (5 November 2014). "[coreboot] AMD's binary-only AGESA libraries". Retrieved 8 September 2019.
  32. ^ "Sage Electronic Engineering - SmartProbe JTAG debugger, Sage EDK, coreboot and Embedded Systems and Software Engineering". www.se-eng.com. Archived from the original on 15 March 2011.
  33. ^ "Sage SmartProbe FAQ". S.Datskovskiy. Retrieved 30 April 2021.
  34. ^ "Depthcharge: The ChromeOS bootloader". docs.google.com. Retrieved 26 October 2015.
  35. ^ "Modify u-boot code to allow building coreboot payload. [chromiumos/third_party/u-boot-next : chromeos-v2011.03]". 24 July 2011.
  36. ^ "Binary Blob Reduction Policy". 1 November 2023. Archived from the original on 1 November 2023. Retrieved 1 November 2023.
  37. ^ "osboot project". 15 March 2021. Archived from the original on 15 March 2021. Retrieved 26 May 2023.
  38. ^ "Libreboot – Osboot is now part of Libreboot". 19 December 2022. Archived from the original on 19 December 2022. Retrieved 26 May 2023.
  39. ^ "How to install ChromeOS Flex on a Chromebook". Android Police. 17 April 2022. Retrieved 30 May 2023.
  40. ^ "GNU Boot Summary". 30 October 2023. Archived from the original on 30 October 2023. Retrieved 30 October 2023.
  41. ^ "Canoeboot project". 16 November 2023. Archived from the original on 16 November 2023. Retrieved 16 November 2023.
  42. ^ "3mdeb Sp. z o.o. — Embedded Firmware development consultancy". 29 January 2024. Archived from the original on 16 February 2024. Retrieved 16 February 2024.
  43. ^ "Dasharo • GitHub". 22 October 2023. Archived from the original on 16 February 2024. Retrieved 16 February 2024.
  44. ^ "About Dasharo - Dasharo Universe". 9 February 2024. Archived from the original on 16 February 2024. Retrieved 16 February 2024.
  45. ^ Kepplinger-Novakovic, Martin (28 May 2024), merge/skulls, retrieved 29 May 2024
  46. ^ "About Heads". Heads. Retrieved 29 May 2024.
  47. ^ linuxboot/heads, LinuxBoot, 28 May 2024, retrieved 29 May 2024

Further reading

Read other articles:

Bang Na Expressway

Jalan Bangna-Bangpakong Bang Na Expressway adalah jembatan jalan tol di Thailand. Jembatan ini sempat dinobatkan sebagai jembatan terpanjang di dunia antara tahun 2000 sampai sebelum Weihe Grand Bridge (79 km) selesai dibangun tahun 2008 di RRC. Bang Na Expressway memiliki total panjang 54 km. Didesain oleh Jean Muller International, kelompok teknisi jembatan dari Prancis.Jembatan ini diselesaikan pada bulan Maret tahun 2000 dan membutuhkan 1,8 juta meter kubik beton. Jembatan ini mampu menga...

 

 

Первородный грех

Об экономическом термине см. Первородный грех (экономика). ХристианствоБиблия Ветхий Завет Новый Завет Евангелие Десять заповедей Нагорная проповедь Апокрифы Бог, Троица Бог Отец Иисус Христос Святой Дух История христианства Апостолы Хронология христианства Ран�...

 

 

Kadipaten Schleswig

Kadipaten SchleswigHerzogtum Schleswig / Hertugdømmet Slesvig1058–1866 Lambang StatusKefiefan DenmarkPemerintahanKadipatenAdipati • 1058-1095 Olaf I dari Denmark• 1863-1866 Christian IX dari Denmark Sejarah • Didirikan 1058• Dibubarkan 1866 Digantikan oleh krjKerajaan Prussia Sunting kotak info • Lihat • BicaraBantuan penggunaan templat ini Schleswig atau Jutlandia Selatan (bahasa Denmark: Sønderjylland atau Slesvig; Jerman: Schleswi...

Film stock

Medium used for recording motion pictures This article is about motion-picture film. For still-photography film, see Photographic film. Film roll redirects here. For the photographic film roll, see roll film. This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.Find sources: Film stock – news · newspapers · books · scholar · ...

 

 

コルク

この記事は検証可能な参考文献や出典が全く示されていないか、不十分です。出典を追加して記事の信頼性向上にご協力ください。（このテンプレートの使い方）出典検索?: コルク – ニュース · 書籍 · スカラー · CiNii · J-STAGE · NDL · dlib.jp · ジャパンサーチ · TWL（2017年4月） コルクを打ち抜いて作った瓶の栓 コルク（木栓、�...

 

 

Islas San Juan

Islas San Juan San Juan Islands Las islas San Juan desde el monte Constitution (isla Orcas) mirando hacia Seattle, con el monte Rainier en el fondo, apenas visible en la nieblaUbicación geográficaArchipiélago Archipiélago de San JuanMar Océano PacíficoEstrecho Estrecho de Georgia- Estrecho de Juan de FucaContinente América del NorteCoordenadas 48°31′55″N 123°01′45″O / 48.532066, -123.029251Ubicación administrativaPaís  Estados UnidosDivisión  Wash...

2016年美國總統選舉

2016年美國總統選舉 ← 2012 2016年11月8日 2020 → 538個選舉人團席位獲勝需270票民意調查投票率55.7%[1][2] ▲ 0.8 %   获提名人 唐納·川普 希拉莉·克林頓 政党 共和黨 民主党 家鄉州 紐約州 紐約州 竞选搭档 迈克·彭斯 蒂姆·凱恩 选举人票 304[3][4][註 1] 227[5] 胜出州/省 30 + 緬-2 20 + DC 民選得票 62,984,828[6] 65,853,514[6]...

 

 

Querido Moheno

Mexican politician Querido Moheno Tabares on April 21, 1914 Querido Moheno Tabares (3 December 1873 – 1933) was the Secretary of Foreign Affairs in Mexico from 1913 to 1914.[1] Querido Moheno Tabares and family in the 1910s References ^ Protest Against Depleting the Garrison of Mexico City. New York Times. October 13, 1913. Retrieved 2010-03-21. Querido Moheno, the Minister of Foreign Affairs, called the members of the Diplomatic Corps together Saturday morning and informed them...

 

 

حمود محمد عبد الله شرف الدين

  لمعانٍ أخرى، طالع حمود محمد (توضيح). حمود محمد عبد الله شرف الدين معلومات شخصية الميلاد 1938كوكبان، محافظة المحويت. الوفاة 1996القاهرة، محافظة القاهرة. الجنسية  اليمن الحياة العملية النوع الشعر الغنائي. المهنة كاتب، شاعر. بوابة الأدب تعديل مصدري - تعديل   حمود محمد ع...

Adam Smith

Scottish economist and philosopher (1723–1790) For other people named Adam Smith, see Adam Smith (disambiguation). Adam SmithFRS FRSE FRSA1787 portraitBornc. 16 June [O.S. c. 5 June] 1723[1]Kirkcaldy, Fife, ScotlandDied17 July 1790(1790-07-17) (aged 67)Edinburgh, ScotlandAlma mater University of Glasgow Balliol College, Oxford Notable work The Theory of Moral Sentiments (1759) The Wealth of Nations (1776) EraEarly modern periodRegionWestern phil...

 

 

Ontario Parks

Provincial government ministry protecting parks in Ontario Ontario ParksAgency overviewFormed1893 (1893)JurisdictionGovernment of OntarioHeadquarters300 Water Street, Peterborough, OntarioMinister responsibleAndrea Khanjin, Minister of the EnvironmentWebsitewww.ontarioparks.com Ontario Parks is a branch of the Ministry of the Environment, Conservation and Parks in Ontario, Canada, that protects significant natural and cultural resources in a system of parks and protected areas that is su...

 

 

Žan Celar

Žan CelarNazionalità Slovenia Altezza187 cm Peso80 kg Calcio RuoloAttaccante Squadra Lugano CarrieraGiovanili 2012-2014 Triglav2014-2017 Maribor2017-2019 Roma Squadre di club1 2016-2017 Maribor1 (0)2018-2019 Roma1 (0)2019-2020→  Cittadella10 (1)2020-2021→  Cremonese38 (4)2021- Lugano95 (40) Nazionale 2015-2016 Slovenia U-176 (2)2016-2017 Slovenia U-186 (3)2017 Slovenia U-193 (3)2019-2021 Slovenia U-2110 (1)2021- Slovenia11 (0) 1 I due nu...

Antonín Dvořák Theatre

Opera house in Ostrava, Czech Republic Antonín Dvořák TheatreDivadlo Antonína DvořákaAntonín Dvořák Theatre, Ostrava.AddressSmetanovo náměstí 3104OstravaCzech RepublicCoordinates49°49′57″N 18°17′28.32″E / 49.83250°N 18.2912000°E / 49.83250; 18.2912000Opened1918WebsiteOfficial website The Antonín Dvořák Theatre (Czech: Divadlo Antonína Dvořáka) is an opera house in Ostrava, Czech Republic, which opened in 1907. Since 1919 it has been one of...

 

 

الدوري التونسي لكرة اليد 1970–71

الدوري التونسي لكرة اليد للرجال الموسم 1970-1971 البلد تونس  المنظم الجامعة التونسية لكرة اليد  النسخة 16 عدد الفرق 12   الفائز الترجي الرياضي التونسي النادي الإفريقي (الثاني) الدوري التونسي لكرة اليد 1969–70  الدوري التونسي لكرة اليد 1971–72  تعديل مصدري - تعديل   الدو...

 

 

Gabe Okoye

American politician from Georgia Gabe OkoyeMember of the Georgia House of Representativesfrom the 102nd districtIncumbentAssumed office January 9, 2023Preceded byConstituency established Personal detailsCitizenshipUnited States  Nigeria Gabe Okoye is Nigerian–American civil engineer, former chair, and a current commissioner of planning in Gwinnett County.[1][2] On November 8, 2022, he became a legislator elect at the 2022 US midterm elections repres...

Сандерс, Берни

В Википедии есть статьи о других людях с фамилией Сандерс. Берни Сандерсангл. Bernie Sanders Сенатор от штата Вермонт с 3 января 2007 Предшественник Джеймс Джеффордс Член Палаты представителей от штата Вермонт 3 января 1991 — 3 января 2007 Предшественник Питер П. Смит[англ.] Пр�...

 

 

Zac Rosscup

American baseball player (born 1988) Baseball player Zac RosscupRosscup with the Los Angeles Dodgers in 2018Toros de Tijuana – No. 58Relief pitcherBorn: (1988-06-09) June 9, 1988 (age 36)Clackamas, Oregon, U.S.Bats: RightThrows: LeftMLB debutSeptember 3, 2013, for the Chicago CubsMLB statistics (through 2021 season)Win–loss record5–2Earned run average5.09Strikeouts117 Teams Chicago Cubs (2013–2015, 2017) Colorado Rockies (2017) Los Angeles Dodgers (2018) Seattle Ma...

 

 

Light Bringer (Brown novel)

2023 science fiction novel by Pierce Brown Light Bringer First edition coverAuthorPierce BrownLanguageEnglishGenreScience fictionPublisherDel Rey Books (US)Publication dateJuly 25, 2023Publication placeUnited StatesMedia type Print (hardcover) E-book Audiobook ISBN978-0-425-28597-8Preceded byDark Age Followed byRed God  Light Bringer is a 2023 science fiction novel by American author Pierce Brown, the third book of a tetralogy which continues the story of his Red Risi...

Strain (mechanics)

Symmetric tensor quantity of the strain caused by stress in matter StrainOther namesStrain tensorSI unit1Other units%In SI base unitsm/mBehaviour undercoord transformationtensorDimension 1 {\displaystyle 1} Part of a series onContinuum mechanics J = − D d φ d x {\displaystyle J=-D{\frac {d\varphi }{dx}}} Fick's laws of diffusion Laws Conservations Mass Momentum Energy Inequalities Clausius–Duhem (entropy) Solid mechanics Deformation Elasticity linear Plasticity Hooke...

 

 

Altar de la Patria

This article is about the mausoleum in Santo Domingo. For the monument in Rome, see Altare della Patria. For the monument in Mexico City, see Altar a la Patria. Historic site in Santo Domingo, Dominican RepublicAltar of the HomelandNative name Spanish: Altar de la PatriaView of the Altar from the Independence ParkLocationSanto Domingo, Dominican RepublicCoordinates18°28′16″N 69°53′33″W / 18.471237°N 69.892416°W / 18.471237; -69.892416Built1976ArchitectCrist...