What is the firmware software?

 
Firmware such as the ROM BIOS of a personal computer may contain only elementary basic functions of a device and may only provide services to higher-level software. Firmware such as the program of an embedded system may be the only program that will run on the system and provide all of its functions.

History

 Ascher Opler coined the term "firmware" in a 1967 Datamation article.Originally, it meant the contents of a writable control store (a small specialized high speed memory), containing microcode that defined and implemented the computer's instruction set, and that could be reloaded to specialize or modify the instructions that the central processing unit (CPU) could execute. 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 processor machine instructions for BIOS, bootstrap loaders, or the control systems for simple electronic devices such as a microwave oven, remote control, or computer peripheral. 

Consumer products

As of 2010, most portable music players support firmware upgrades. Some companies use firmware updates to add new playable file formats (codecs); iriver added Vorbis playback support this way, for instance. Other features that may change with firmware updates include the GUI or even the battery life. Most mobile phones have a Firmware Over The Air firmware upgrade capability for much the same reasons; some may even be upgraded to enhance reception or sound quality, illustrating that firmware is used at more than one level in complex products (in a CPU-like microcontroller versus in a digital signal processor, in this particular case). 

Automobiles

Since 1996, most automobiles 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 systems (ABS) and computer-operated transmission control units (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.  

Flashing

Flashing involves the overwriting of existing firmware or data, contained in EEPROM or flash memory modules present in an electronic device, with new data.This can be done to upgrade a device 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.  

Firmware hacking

Sometimes, third parties create 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 projects for video game consoles, which often unlock general-purpose computing functionality in previously limited devices (e.g., running Doom on iPods).

Firmware hacks usually take advantage of the firmware update facility on many devices to install or run themselves. Some, however, must resort to exploits to run, because the manufacturer has attempted to lock the hardware to stop it from running unlicensed code.Most firmware hacks are free software.