Editing Firmware

{{Short description|Low-level computer software}}

[[File:WD Blue WD5000LPVX - controller - Winbond 25X20CLVIG-0182.jpg|thumb|right|Firmware is commonly stored in an [[EEPROM]] or Flash memory,<ref>{{cite web |url=https://www.winbond.com/hq/support/documentation/?__locale=en&line=/product/code-storage-flash-memory/index.html&family=/product/code-storage-flash-memory/serial-nor-flash/index.html&pno=W25X20CL&category=/.categories/resources/datasheet/ |title=W25X20CL Datasheet |publisher=[[Winbond]] |access-date=2024-08-30}}</ref> which makes use of an I/O protocol such as [[Serial Peripheral Interface|SPI]].]]

In [[computing]], '''firmware''' is [[software]] that provides [[low-level]] control of [[computing device]] [[Computer hardware|hardware]]. 
For a relatively simple device, firmware may perform all control, monitoring and data manipulation functionality.
For a more complex device, firmware may provide relatively low-level control as well as [[hardware abstraction]] [[Service (systems architecture)|services]] to higher-level software such as an [[operating system]].

Firmware is found in a wide range of computing devices including [[personal computer]]s, [[smartphone]]s, [[home appliances]], [[vehicles]], [[computer peripherals]] and in many of the [[integrated circuit]]s inside each of these larger systems.

Firmware is stored in [[non-volatile memory]] {{endash}} either [[read-only memory]] (ROM) or programmable memory such as [[EPROM]], [[EEPROM]], or [[flash memory|flash]]. Changing a device's firmware stored in ROM requires physically replacing the memory chip {{endash}} although some chips are not designed to be removed after manufacture. Programmable firmware memory can be reprogrammed via a procedure sometimes called ''[[Flashing (technology)|flashing]]''.<ref>{{cite web| title=What is firmware? |url=http://incepator.pinzaru.ro/software/what-is-firmware/ |date=23 January 2013}}</ref>

Common reasons for [[Patch (computing)|changing]] firmware include fixing [[Bug (engineering)|bugs]] and adding [[Feature (software design)|features]].

== History and etymology ==
Ascher Opler used the term ''[[:wikt:firmware|firmware]]'' in a 1967 ''[[Datamation]]'' article, as an intermediary term between ''hardware'' and ''software''. Opler projected that fourth-generation computer systems would have a [[writable control store]] (a small specialized high-speed memory) into which [[microcode]] firmware would be loaded. Many software functions would be moved to microcode, and [[instruction set]]s could be customized, with different firmware loaded for different instruction sets.<ref name="Opler">
{{cite journal |author=Opler, Ascher |date=January 1967 |title=Fourth-Generation Software |url=https://archive.org/details/TNM_4th_generation_software_hardware_-_Datamation_20171010_0125 |journal=Datamation |volume=13 |issue=1 |pages=22–24}}</ref>

As computers began to increase in complexity, it became clear that various programs needed to first be initiated and run to provide a consistent environment necessary for running more complex programs at the user's discretion. This required programming the computer to run those programs automatically. Furthermore, as companies, universities, and marketers wanted to sell computers to laypeople with little technical knowledge, greater automation became necessary to allow a lay-user to easily run programs for practical purposes. This gave rise to a kind of software that a user would not consciously run, and it led to software that a lay user wouldn't even know about.<ref>{{cite web |publisher=Lumen |title=Introduction to Computer Applications and Concepts. Module 3: System Software |url=https://courses.lumenlearning.com/zeliite115/chapter/reading-firmware/}}</ref>

As originally used, firmware contrasted with hardware (the CPU itself) and software (normal instructions executing on a CPU). It was not composed of CPU machine instructions, but of lower-level microcode involved in the implementation of machine instructions. It existed on the boundary between hardware and software; thus the name ''firmware''. Over time, popular usage extended the word ''firmware'' to denote any computer program that is tightly linked to hardware, including [[BIOS]] on PCs, [[boot firmware]] on smartphones, [[computer peripheral]]s, or the control systems on simple [[consumer electronic devices]] such as [[microwave oven]]s and [[remote control]]s.

== Applications ==

=== Computers ===
[[File:AMI 486DX EISA BIOS 20051109.jpg|thumb|right|ROM [[BIOS]] firmware on a [[Baby AT]] [[motherboard]]]]

In some respects, the various firmware components are as important as the [[operating system]] in a working computer. However, unlike most modern operating systems, firmware rarely has a well-evolved automatic mechanism of updating itself to fix any functionality issues detected after shipping the unit.

A computer's firmware may be manually updated by a user via a small utility program. In contrast, firmware in mass storage devices (hard-disk drives, optical disc drives, flash memory storage e.g. solid state drive) is less frequently updated, even when flash memory (rather than ROM, EEPROM) storage is used for the firmware.

Most computer peripherals are themselves special-purpose computers. Devices such as printers, scanners, webcams, and [[USB flash drive]]s have internally-stored firmware; some devices may also permit field upgrading of their firmware. For modern simpler devices, such as [[USB keyboard]]s, [[USB mouse]]s and [[USB sound card]]s, the trend is to store the firmware in on-chip memory in the device's [[microcontroller]], as opposed to storing it in a separate [[EEPROM]] chip.

Examples of computer firmware include:
* The [[BIOS]] firmware used on PCs
* The [[Unified Extensible Firmware Interface|(U)EFI]]-compliant firmware used on [[Itanium]] systems, Intel-based [[Mac (computer)|Mac]]s, and many newer PCs
* [[Hard disk drive]], [[solid-state drive]], [[optical disc drive]] and optical disc recorder firmware<ref>{{Cite journal |last=Mielewczik |first=Michael |date=2000 |title=Firmware-Update. Mehr Speed und Sicherheit |journal=PC Praxis |language=German |volume=1/2000 |pages=68}}</ref>
* [[Video BIOS]] of a [[graphics card]]
* [[Open Firmware]], used in [[SPARC]]-based computers from [[Sun Microsystems]] and [[Oracle Corporation]], [[PowerPC]]-based computers from Apple, and computers from [[Genesi]]
* [[ARCS (computing)|ARCS]], used in computers from [[Silicon Graphics]]
* [[Kickstart (Amiga)|Kickstart]], used in the [[Amiga]] line of computers ([[Power-on self-test|POST]], hardware init + [[Plug and Play]] [[Autoconfig|auto-configuration]] of peripherals, [[kernel (operating system)|kernel]], etc.)
* [[Run-Time Abstraction Services|RTAS]] (Run-Time Abstraction Services), used in [[IBM System i|System i]] and [[System p]] computers from [[IBM]]
* The [[Common Firmware Environment]] (CFE) for [[Broadcom]] [[systems-on-chip]] (SoCs)
[[File:Firmware update Fuji Instax Liplay.jpg|thumb|Updating the firmware of a [[Instax|Fuji Instax]] camera]]

=== Home and personal-use products ===
Consumer appliances like [[gaming console]]s, [[digital camera]]s and [[portable music player]]s support firmware upgrades. Some companies use firmware updates to add new playable file formats ([[codecs]]). Other features that may change with firmware updates include the GUI or even the battery life. [[Smartphone]]s have a [[firmware over the air]] upgrade capability for adding new features and patching security issues.

=== Automobiles ===
Since 1996, most [[automobile]]s have employed an on-board computer and various sensors to detect mechanical problems. {{As of|2010}}, modern vehicles also employ computer-controlled [[anti-lock braking system]]s (ABS) and computer-operated [[transmission control unit]]s (TCUs). The driver can also get in-dash information while driving in this manner, such as real-time fuel economy and tire pressure readings. Local dealers can update most vehicle firmware.

=== Other examples ===
Other firmware applications include:
* In home and personal-use products:
** Timing and control systems for [[washing machine]]s
** Controlling sound and video attributes, as well as the channel list, in modern [[television]]s
* In [[Network router|routers]], [[Network switch|switches]], and [[Firewall (computing)|firewalls]]:
** [[LibreCMC]]{{snd}} a 100% [[free software]] router distribution based on the [[Linux-libre]] kernel
** [[IPFire]]{{snd}} an [[Open-source software|open-source]] firewall/router distribution based on the [[Linux kernel]]
** [[fli4l]]{{snd}} an open-source firewall/router distribution based on the Linux kernel
** [[OpenWrt]]{{snd}} an open-source firewall/router distribution based on the Linux kernel
** [[m0n0wall]]{{snd}} an embedded firewall distribution of [[FreeBSD]]
** [[Proprietary firmware]]
* In [[Network-attached storage|NAS]] systems:
** [[NAS4Free]]{{snd}} an open-source NAS operating system based on FreeBSD
** [[Openfiler]]{{snd}} an open-source NAS operating system based on the Linux kernel
** [[Proprietary firmware]]
* [[Field-Programmable Gate Array]] (FPGA) code may be referred to as firmware

== Flashing ==
''Flashing''<ref name=techfaq /> is a process that involves the overwriting of existing firmware or data, contained in [[EEPROM]] or [[flash memory]] module present in an electronic device, with new data.<ref name=techfaq>{{cite web|url=http://www.tech-faq.com/flashing-firmware.html|title=Flashing Firmware|publisher=Tech-Faq.com|access-date=July 8, 2011|url-status=live|archive-url=https://web.archive.org/web/20110927010726/http://www.tech-faq.com/flashing-firmware.html|archive-date=September 27, 2011}}</ref> This can be done to upgrade a device<ref>{{cite web
|url= http://developer.htc.com/adp.html
|archive-url=https://web.archive.org/web/20110426201145/http://developer.htc.com/adp.html
|title=HTC Developer Center|publisher=[[HTC]]
|access-date=July 8, 2011
|archive-date=April 26, 2011
}}</ref> or to change the provider of a service associated with the function of the device, such as changing from one mobile phone service provider to another or installing a new operating system. If firmware is upgradable, it is often done via a program from the provider, and will often allow the old firmware to be saved before upgrading so it can be reverted to if the process fails, or if the newer version performs worse. Free software replacements for vendor flashing tools have been developed, such as [[Flashrom (utility)|Flashrom]].

== Firmware hacking ==
{{Main|Custom firmware}}

Sometimes, third parties develop an unofficial new or modified ("aftermarket") version of firmware to provide new features or to unlock hidden functionality; this is referred to as [[custom firmware]]. An example is [[Rockbox]] as a firmware replacement for [[portable media players]]. There are many [[homebrew (video games)|homebrew]] projects for various devices, which often unlock general-purpose computing functionality in previously limited devices (e.g., running [[Doom (1993 video game)|Doom]] on [[iPod]]s).

Firmware hacks usually take advantage of the firmware update facility on many devices to install or run themselves. Some, however, must resort to [[exploit (computer security)|exploit]]s to run, because the manufacturer has attempted to lock the hardware to stop it from running [[unsigned code|unlicensed code]].

Most firmware hacks are [[free software]].

=== HDD firmware hacks ===
The Moscow-based [[Kaspersky Lab]] discovered that a group of developers it refers to as the [[Equation Group]] has developed [[hard disk drive]] firmware modifications for various drive models, containing a [[Trojan horse (computing)|trojan horse]] that allows data to be stored on the drive in locations that will not be erased even if the drive is formatted or wiped.<ref>{{cite web|url=http://www.kaspersky.com/about/news/virus/2015/Equation-Group-The-Crown-Creator-of-Cyber-Espionage|title=Equation Group: The Crown Creator of Cyber-Espionage|publisher=[[Kaspersky Lab]]|date=February 16, 2015|url-status=live|archive-url=https://web.archive.org/web/20151202101934/http://www.kaspersky.com/about/news/virus/2015/equation-group-the-crown-creator-of-cyber-espionage|archive-date=December 2, 2015}}</ref>  Although the Kaspersky Lab report did not explicitly claim that this group is part of the United States [[National Security Agency]] (NSA), evidence obtained from the code of various Equation Group software suggests that they are part of the NSA.<ref>{{cite web|title=How "omnipotent" hackers tied to NSA hid for 14 years—and were found at last|author1=Dan Goodin|website=[[Ars Technica]]|date=February 2015|url=https://arstechnica.com/security/2015/02/how-omnipotent-hackers-tied-to-the-nsa-hid-for-14-years-and-were-found-at-last/|url-status=live|archive-url=https://web.archive.org/web/20160424062759/http://arstechnica.com/security/2015/02/how-omnipotent-hackers-tied-to-the-nsa-hid-for-14-years-and-were-found-at-last/|archive-date=2016-04-24}}</ref><ref>{{cite web|publisher=[[Daily Kos]]|url=https://www.dailykos.com/story/2015/02/17/1364910/-Breaking-Kaspersky-Exposes-NSA-s-Worldwide-Backdoor-Hacking-of-Virtually-All-Hard-Drive-Firmware|title=Breaking: Kaspersky Exposes NSA's Worldwide, Backdoor Hacking of Virtually All Hard-Drive Firmware|date=February 17, 2015|url-status=live|archive-url=https://web.archive.org/web/20150225044646/http://www.dailykos.com/story/2015/02/17/1364910/-Breaking-Kaspersky-Exposes-NSA-s-Worldwide-Backdoor-Hacking-of-Virtually-All-Hard-Drive-Firmware|archive-date=February 25, 2015}}</ref>

Researchers from the Kaspersky Lab categorized the undertakings by Equation Group as the most advanced hacking operation ever uncovered, also documenting around 500 infections caused by the Equation Group in at least 42 countries.

== Security risks ==
[[Mark Shuttleworth]], the founder of the company [[Canonical (company)|Canonical]], which created the [[Ubuntu Linux]] distribution, has described [[Proprietary software|proprietary]] firmware as a security risk, saying that "firmware on your device is the [[NSA]]'s best friend" and calling firmware "a trojan horse of monumental proportions". He has asserted that low-quality, [[closed source]] firmware is a major threat to system security:<ref name="linux-mag-162">{{cite magazine |title=Shuttleworth Calls for Declarative Firmware |magazine=Linux Magazine |issue=162 |date=May 2014 |page=9 }}</ref> "Your biggest mistake is to assume that the NSA is the only institution abusing this position of trust{{snd}} in fact, it's reasonable to assume that all firmware is a cesspool of insecurity, courtesy of incompetence of the highest degree from manufacturers, and competence of the highest degree from a very wide range of such agencies".  As a potential solution to this problem, he has called for declarative firmware, which would describe "hardware linkage and dependencies" and "should not include [[executable code]]".<ref>{{cite web|url=http://www.markshuttleworth.com/archives/1332|title=ACPI, firmware and your security|first1=Mark|last1=Shuttleworth|author-link=Mark Shuttleworth|date=March 17, 2014|url-status=live|archive-url=https://web.archive.org/web/20150315054919/http://markshuttleworth.com/archives/1332|archive-date=March 15, 2015}}</ref> Firmware should be [[Open-source software|open-source]] so that the code can be checked and verified.

Custom firmware hacks have also focused on injecting [[malware]] into devices such as smartphones or [[USB device]]s. One such smartphone injection was demonstrated on the [[Symbian OS#Malware|Symbian OS]] at [[MalCon]],<ref>{{cite web |url=http://malcon.org/web/techbrief/malcon-2010-technical-briefings/ |title=MalCon 2010 Technical Briefings |website=Malcon.org  |url-status=dead |archive-url=https://web.archive.org/web/20110704040605/http://malcon.org/web/techbrief/malcon-2010-technical-briefings/ |archive-date=2011-07-04 }}</ref><ref>{{cite web|url=http://www.h-online.com/security/news/item/Hacker-plants-back-door-in-Symbian-firmware-1149926.html |archive-url=https://web.archive.org/web/20130521142131/http://www.h-online.com/security/news/item/Hacker-plants-back-door-in-Symbian-firmware-1149926.html|archive-date=21 May 2013|title=Hacker plants back door in Symbian firmware |website=H-online.com |date=2010-12-08 |access-date=2013-06-14}}</ref> a [[hacker convention]]. A USB device firmware hack called [[BadUSB]] was presented at the [[Black Hat Briefings|Black Hat USA 2014]] conference,<ref>{{cite web |url=https://www.wired.com/2014/07/usb-security/ |title=Why the Security of USB Is Fundamentally Broken |website=Wired.com |date=2014-07-31 |access-date=2014-08-04 |url-status=live |archive-url=https://web.archive.org/web/20140803200841/http://www.wired.com/2014/07/usb-security/ |archive-date=2014-08-03 }}</ref> demonstrating how a [[USB flash drive]] microcontroller can be reprogrammed to spoof various other device types to take control of a computer, exfiltrate data, or spy on the user.<ref>{{cite web |url=https://www.blackhat.com/us-14/briefings.html#badusb-on-accessories-that-turn-evil |title=BadUSB - On Accessories that Turn Evil |website=BlackHat.com |access-date=2014-08-06 |url-status=live |archive-url=https://web.archive.org/web/20140808053344/https://www.blackhat.com/us-14/briefings.html#badusb-on-accessories-that-turn-evil |archive-date=2014-08-08 }}</ref><ref>{{cite web
 |url         = https://srlabs.de/wp-content/uploads/2014/07/SRLabs-BadUSB-BlackHat-v1.pdf
 |title       = BadUSB – On accessories that turn evil
 |date        = 2014-08-07
 |access-date  = 2014-08-23
 |author1     = Karsten Nohl
 |author2     = Sascha Krißler
 |author3     = Jakob Lell
 |website     = srlabs.de
 |url-status   = live
 |archive-url  = https://web.archive.org/web/20161019034729/https://srlabs.de/wp-content/uploads/2014/07/SRLabs-BadUSB-BlackHat-v1.pdf
 |archive-date = 2016-10-19
}}</ref> Other security researchers have worked further on how to exploit the principles behind BadUSB,<ref>{{cite web|url=http://hackingpost.com/badusb-malware-infect-millions-of-usb/|title=BadUSB Malware Released — Infect millions of USB Drives|website=The Hacking Post|access-date=7 October 2014|url-status=unfit|archive-url=https://web.archive.org/web/20141006121457/http://hackingpost.com/badusb-malware-infect-millions-of-usb/|archive-date=6 October 2014}}</ref> releasing at the same time the source code of hacking tools that can be used to modify the behavior of different USB devices.<ref>{{cite magazine|url=https://www.wired.com/2014/10/code-published-for-unfixable-usb-attack/|title=The Unpatchable Malware That Infects USBs Is Now on the Loose|magazine=WIRED|access-date=7 October 2014|url-status=live|archive-url=https://web.archive.org/web/20141007092141/http://www.wired.com/2014/10/code-published-for-unfixable-usb-attack/|archive-date=7 October 2014|last1=Greenberg|first1=Andy}}</ref>

== See also ==
{{Portal|Electronics}}

* [[Bootloader]]
* [[Computer hardware]]
* [[Coreboot]]
* [[Custom firmware]]
* [[Microcode]]
* [[Proprietary device driver]]
* [[Real-time operating system]]
* [[ROM image]]

== References ==
{{Reflist}}

{{Firmware and booting}}
{{Embedded systems}}
{{Authority control}}

[[Category:Firmware| ]]