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What is Firmware and what does it do?

23/10/18 Ricky Wilcocks Manager, Electronics & Technology

In today’s world of smart devices, firmware (permanent software programmed into a read-only memory) is an inescapable part of everyday life. Firmware, also commonly referred to as embedded software, powers the microcontroller or microprocessors environment in technology all around us and exists in a wide variety of products ranging from the tv remote control, personal computers, car braking systems, washing machines, heating controllers etc.

Firmware is a small piece of embedded software that makes electronic hardware work. Without firmware, most of today’s electronic devices would not be able to function. They would not do anything.

The firmware of olde, was written once and it was there for the rest of time.  If it was broken, the system was broken.

However, these days electronic devices are built around general-purpose processors, and not so much microcontrollers.  Even cheap devices can be upgraded without too much issue.  Depending on the organisation, firmware could be a full Linux stack in a router with ssh, shell and web servers.  Or it could be microcode being loaded into a low- power microcontroller to achieve some very simple actions.

For more complex hardware, like smartphones, tablets, smart TVs, smartwatches and so on, the firmware is the middleman between the hardware and the operating system. On such devices, the firmware contains only the necessary instructions for the hardware to operate with the operating system that is installed on the device. For example, on a Samsung Galaxy smartphone with Android, the firmware on the smartphone allows the hardware to communicate correctly with the Android operating system and do what is requested by the user.

Firmware, which is added at the time of manufacturing, is used to run user programs on the device and can be thought of as the software that allows hardware to run. Hardware makers use embedded firmware to control the functions of various hardware devices and systems, much like a computer’s operating system (OS) controls the function of software applications. Firmware may be written into read-only memory (ROM), erasable programmable read-only memory (EPROM) or flash memory. The firmware that is embedded in flash memory chips can be updated easier than firmware written to ROM or EPROM, which makes it more adaptable.

The rule of thumb would be to look at a product and appraise where the "smarts" are.  If the user interacts directly with the smarts (touch screen, web interface, etc) then the chances are the firmware, in that case, will be a full Linux stack (or another OS), and so it will be like working under the operating system.  If the user interacts with buttons and lights for feedback, chances are it’s a more traditional firmware written in low-level microcontroller code to achieve the same thing.

Firmware updates are often issued to fix bugs, roll out new features and improve security. Many manufacturers release regular updates for the firmware found on their electronic hardware devices. They also provide the necessary software tools to write the new firmware onto those devices. However, each manufacturer can choose whether it releases a new firmware for an individual device, or not. For instance, most computer parts manufacturers develop and provide customers with new firmware and the corresponding firmware updaters, at least for a few years after the device was launched.

The role of a firmware engineer

Firmware engineers work closely with electronic hardware developers as the software runs directly on the digital hardware platform. They play a vital role in supporting the product lifecycle from its inception to the final implementation.

A firmware engineer works as an essential part of a company's engineering team, designing and developing firmware solutions for technological products to ensure they run effectively without glitches or malfunctions.

The key responsibilities of a firmware engineer are:

  • To confer with the marketing team to understand product expectations, features and requirements.
  • To analyse the needs of the system and define an architecture which meets the scope, performance, limitations, and capabilities of the design brief.
  • To develop and implement a system that is designed within the given budget and time.
  • To design, develop, code (Assembler, C or C++), test and debug system software
  • To validate the system and check its functionality and ensure that it is running and operating smoothly.
  • To evaluate the performance of the system and troubleshoot issues if any.
  • To improvise the software by making some modifications after consulting with the marketing organisation and customer base

Since technology is constantly evolving with new hardware and software released every day, firmware engineers are essential team members both for organisations that manufacture technical solutions and businesses that use their products. The firmware engineer is responsible for developing new guidelines and operating rules for hardware to ensure that technology remains compatible with new and updated information and equipment. With today’s latest technological advancement, the career prospects are really bright for those aspiring to stabilise in the field of firmware engineering.

In a lot of cases, the firmware bucket is the collecting place for "stuff that is close to the hardware, but most of the engineering team in the company doesn't understand".

Find and apply today for the latest Firmware jobs, or contact Ricky Wilcocks R&D and Engineering Manager on 01582 878810 or email