The BIOS is responsible for getting our systems running each time we hit the start button. In this video, you’ll learn about the Basic Input/Output System and how the UEFI BIOS is used to manage and protect our modern computer systems.
When you start your computer, you may notice that the information you’re seeing on your screen is not related to the operating system that ultimately loads. What you’re seeing on the screen is the BIOS, the Basic Input/Output System of your computer. You might also see this referred to as the firmware of your system, and some people refer to this as the system BIOS or ROM BIOS, which is referring to Read-Only Memory. These days, we don’t generally use read-only memory to store the BIOS software. Instead, it’s usually stored on your motherboard in flash memory.
The BIOS is responsible for initializing your system and getting everything ready to run with the operating system that you need to load. The process you see when you start your computer is referred to as the Power-On Self-Test, or POST. This checks for a CPU, makes sure that you have memory installed in the system, that a keyboard and a mouse is connected. And if there are any problems initializing those core systems, you’ll see an error message on your screen.
This process only takes a few seconds, and once this diagnostic is done, it begins to start your operating system. This may begin immediately loading your operating system, or you may receive a prompt requesting you to choose which operating system you’d like to use. This prompt is the bootloader, and it signifies that you’ve completed the POST and is now ready to load the operating system.
As we mentioned earlier, this BIOS software that starts your system is usually stored in flash memory on your motherboard. And if you look closely at your motherboard, it’s probably even marked. On this motherboard, there are two separate BIOS flash chips, one that is a main BIOS and one that is a backup. This allows you to upgrade the BIOS but still keep another copy on standby in case something happens during the upgrade process.
On older PCs, you may find that the BIOS is a traditional or legacy BIOS This is a BIOS type that’s been around for more than 25 years. And if you are running an older operating system on an older piece of hardware, you’re probably using this legacy BIOS. Unfortunately, this older legacy BIOS was designed for older legacy hardware. So if you’re trying to install newer hardware in an older system, you may find that the legacy BIOS is not able to support that hardware.
This is the type of text-based screen that you would see on a legacy BIOS. This is one that uses your mouse keys to be able to move around, and you would choose the enter keys or space keys or perhaps a number of different function keys to change what’s on the screen. You’ll notice there are options available at the bottom of the screen, so you always know what choices you’re able to make on that particular screen.
Our modern hardware needs a modern BIOS. And if you’re using a more modern computer, you’re probably using a UEFI BIOS. That UEFI stands for a Unified Extensible Firmware Interface. This is a standard that was created by Intel, and you’ll find that the UEFI BIOS is used on all modern systems. Because this is a standard, you’ll find that the UEFI functionality is very similar across manufacturers. So it doesn’t matter who manufactures your computer. You’ll find that the options and features available in your UEFI BIOS will be the same from one manufacturer to another.
There are also a number of new user interface features in this UEFI bios. You’ll notice that there are graphical options, and you can use your mouse to be able to move around and manipulate the information that’s on the screen.
The settings that you’ll find within the UEFI BIOS are the things that you might expect for getting your system up and running and ready to load an operating system, things like an overview of the CPU and the type of bios that you’re running. You can see different devices that may be connected to your computer, especially storage devices, audio, and network. You have advanced settings, which allow you to configure CPU features, especially those related to virtualization. There are power options, security, startup, and so much more.
Some of these settings are critical to ensure that your system will continue to perform reliably. So these are not settings that you want to change or modify without knowing exactly what the result of that change is going to be. If you’re planning to make any updates to your BIOS, it’s important that you make backups and have documentation just in case you need to go back to the previous configuration.