What is Firmware and what does it do?

In today’s digitally connected world, firmware plays a crucial role in powering the smart devices we rely on daily. From your TV remote control to smartphones, home appliances, automotive systems, and industrial machinery, firmware is the invisible but indispensable layer that makes electronic hardware work as intended.

Also referred to as embedded software, firmware is a specific class of computer software programmed directly into the hardware’s non-volatile memory (such as ROM, EPROM, or flash memory). It provides the low-level control required for a device's hardware components (microcontrollers or microprocessors) to function and communicate with higher-level systems like operating systems and applications.

How Does Firmware Work?

At its core, firmware acts as the bridge between electronic hardware and software. It initialises hardware components and provides a consistent environment in which higher-level software can operate. Without firmware, most modern electronics wouldn’t be able to boot, communicate, or perform any function.

In simple embedded systems—like a microwave oven, washing machine, or thermostat firmware is often written in low-level languages (e.g., Assembly, C or embedded C++) and stored in read-only memory. It performs a finite number of tasks and rarely needs updates.

In contrast, complex devices such as routers, smartphones, smart TVs, personal computers, and wearables, use firmware as part of a broader architecture. In these systems, firmware may be a full Linux-based operating system, running services like SSH, web servers, and device drivers. This firmware allows the electronic hardware to interface with sophisticated operating systems like Android, iOS, or Windows IoT.

Example: On a Samsung Galaxy device running Android, the firmware ensures proper communication between the physical components (e.g., the touchscreen, camera, or modem) and the operating system. This enables the device to carry out user commands efficiently.

Types of Firmware Memory

Firmware is stored in several types of non-volatile memory:

• ROM (Read-Only Memory): Traditionally used for permanent firmware. Once written, it cannot be modified.

• EPROM (Erasable Programmable ROM): Can be erased with ultraviolet light and reprogrammed.

• Flash Memory: Most commonly used today. It supports firmware updates, allowing manufacturers to patch bugs, enhance features, and address cybersecurity vulnerabilities.

✅  Tip: When searching for firmware updates, always visit the official website of your device's manufacturer to ensure security and compatibility.

Why Are Firmware Updates Important?

Modern firmware is no longer "write once, never change." As devices become more complex, firmware is routinely updated to:

• Fix bugs and security vulnerabilities
• Improve performance and stability
• Add new features and support for updated hardware

Manufacturers typically offer firmware updates via downloadable tools or over-the-air (OTA) mechanisms. Examples include BIOS updates for PCs, router firmware upgrades, and smartwatch OS patches.

💡 Tip: For guidance on updating firmware safely, check resources like Intel’s BIOS Update Guide or your specific product’s support portal.

How to Identify Firmware in a Device

A good rule of thumb is to examine where the device’s intelligence lies:

• If the user interacts through a touchscreen or web interface, the firmware may be a full-fledged OS.

• If the device uses simple buttons and LEDs, it likely runs on traditional firmware coded for microcontrollers like ARM Cortex-M, AVR, or PIC.

 What Does a Firmware Engineer Do?

Firmware engineers are specialists who develop low-level software for embedded systems. They work closely with electronic hardware teams to ensure smooth integration, performance, and product functionality.

Key Responsibilities:

• Collaborate with product and marketing teams to define features, scope, performance and requirements.
• Architect and design embedded systems within time and budget constraints.
• Write efficient code in C, C++, or Assembly for microcontrollers or processors.
• Develop, test, debug, and maintain embedded software systems.
• Validate system functionality, troubleshoot bugs, and release OTA updates.
• Ensure compliance with industry standards and customer requirements.

Firmware engineers are vital in industries such as:

• Consumer electronics
• Automotive systems
• Medical devices
• Aerospace and defence
• Industrial automation

As smart technology evolves, demand for experienced firmware engineers continues to rise. Firmware roles combine software development, electronic hardware integration, and problem-solving, making them both challenging and rewarding.

Why Work in Firmware Engineering?

Working in firmware development offers:

• Competitive salaries.
• High demand across multiple sectors.
• Opportunities for international travel and cutting-edge projects.
• Continuous learning in fast-paced technology environments.

At Redline Group, we have over four decades of experience connecting skilled engineers with the UK's leading technology businesses. Whether you’re a junior developer or a senior embedded systems architect, our specialist R&D recruitment consultants can help you find the perfect role.

🔎 Search current opportunities: Explore Firmware Engineering Jobs

Conclusion

Firmware is the unseen but essential foundation of today’s smart devices. From enabling device boot sequences to managing critical hardware functions, it’s an indispensable part of modern technology. Whether you’re an engineering student, a tech enthusiast, or a hiring manager in the electronics industry, understanding firmware and embedded software is key to unlocking the future of innovation.

Redline changes lives every day, building world-class teams for technology and engineering companies. With four decades of experience, our knowledge-led people tailor recruitment solutions to suit clients’ specific needs.

If you would like more advice, tips, inspiration or if you need guidance to discuss a career or job in embedded systems, 📞 contact Redline on 01582 450054 or email info@redlinegroup.com