A simple firmware definition is that firmware is low-level code that runs on the hardware. In other words, it's the software on your hardware.
The various hardware items on your phone or computer have to talk to each other. The keyboard can only talk to the motherboard because of the firmware in each system. The hardware is useless without a device's firmware, and the software would not be able to run.
Firmware is explicitly written for specific hardware devices. Therefore, you almost always need the actual hardware to load your code onto to write firmware to see if your draft works. It was initially often found in flash memory chips but is now embedded in computer hardware.
Firmware varies in its complexity. It can use standard communication protocols to enable different hardware devices to communicate or develop business logic.
Firmware can be “bare metal” low-level firmware or, in its more complex forms, such as motherboard firmware, can be high-level firmware using a “real-time operating system” or “RTOS.”
Once the firmware is written, it is “compiled” or turned into machine code, which the hardware can act on. This compiled code is then uploaded or flashed onto the device. Once this flashing is complete, the device boots up and begins to run the compiled code.
This often involves debugging tools attached to the hardware and specific equipment like oscilloscopes, logic analyzers, and multimeters. These tools allow the engineer to verify the hardware functions correctly.
All hardware inside a computer - motherboard, memory, hard drive, displays, USB, fans- requires hardware to run firmware. This firmware enables all hardware to communicate so your computer can run. The basic input/output system (BIOS) is an example of firmware in a PC. It lets the microprocessor's program start the device when you turn it on. It also allows the PC’s operating system to communicate with connected devices, such as your keyboard, mouse, printer, and other peripherals.
The firmware also enables personal devices - your wifi router, phone, TV, appliances, wireless and Bluetooth devices, smart locks, and doorbells. Even a defibrillator uses firmware. In other words, pretty much all personal electronic devices are running firmware.
Cars are complex and only getting more complicated as they become self-driving, self-parking, automatic braking, collision-avoiding wonder machines.
Modern cars are way more complex than your phone and computer. And all of them can do far more than the computers that got Apollo to the moon.
Robotics - keeping all the automatic systems running.
Military applications - making sure the missiles and smart bombs go where they should, and the drones see what they should.
Medical devices - robotic surgery and modern sensors need to be running and up to date. Even blood sugar testing can now be done through a mobile app.
Telecommunications systems are mission-critical to businesses and homes.
The software consists of the applications you interact with, like web browsers or Microsoft Office. If you think about how the software gets signals from the hardware when, for instance, a user presses a key, you are thinking about firmware. That’s where firmware comes in. Firmware is the “low-level” code that runs directly on the hardware that acts as a bridge between the hardware and the software. Without firmware, your computer can't know how to communicate with a keyboard or the screen. Not firmware, device drivers are special software needed to make a given accessory work within a given operating system.
The term "firmware" originated in a computer magazine in 1967. Back then, the term meant the contents of a small high-speed memory that housed a microcode that defined and implemented a computer's instruction set. There weren't instructions for the central processing unit (CPU). Instead, it used a lower level microcode to implement machine instructions existing between hardware and software.
Today, "firmware" refers to any computer program tightly linked to hardware. It is even found in a simple electronic device like a microwave, remote, or computer peripheral.
Devices run a compiled version of code optimized to a “machine code” that the device understands and acts on. Updates to firmware are as necessary as software updates. Updates adding to or rewriting the existing firmware to the device are as efficient as possible. They may happen every few years or far more frequently for devices that are often connected to the internet or need up-to-date security. Standard devices that get frequent updates to firmware include:
Devices can handle firmware updates in different ways, but this is usually done with the help of a “bootloader.” A bootloader is a tiny piece of code separate from the compiled application that solely handles determining which version of code to run. A new firmware image is downloaded, and the bootloader is invoked when you update. The bootloader determines whether the firmware image is valid and okay to run. The new image is run as is the default new image. Some devices can hold multiple images as a fallback in the event of an issue with the new image.
It's essential to update your firmware properly; doing it poorly can render your device non-functional. Usually, there will be information about the device's model and firmware version somewhere on your device. Find that before doing anything yourself. Once you know that, you can find out if an update is available by checking the developer's website—backup your current firmware before doing an update and then do it. Updating frequently is a good thing, but only if you are very careful to do it accurately. Most firmware will update automatically.
As you can see, firmware is perhaps the most significant IT vulnerability facing digital product users. Most companies and individual users are aware of letting their computers and other devices have automatic software updates. Most manufacturers and software developers encourage doing so. However, most people and companies do not engage in the often very manual process of updating firmware. It can be challenging even to find updates for your firmware and risky for the inexperienced to attempt at all. Firmware needs to become as easily and unthinkingly updatable as software. Microsoft has updated its Windows 10 and 11 computers to be more secure on this issue, but the user must act as well.