What is csm bios?

CSM BIOS stands for Compatibility Support Module Basic Input/Output System. It is a feature included in modern UEFI (Unified Extensible Firmware Interface) firmware that allows legacy BIOS operating systems and software to run on systems that have UEFI firmware.

The CSM BIOS provides the necessary compatibility layer to allow older operating systems, such as Windows 7 or older versions of Linux, to boot and run on newer UEFI-based systems. It essentially bridges the gap between the older BIOS systems and the newer UEFI systems, allowing for a seamless transition between the two.

CSM BIOS also allows for the use of legacy hardware components and devices that are not natively supported by UEFI firmware. This can be useful for users who have older peripherals or hardware that they still want to use on newer systems.

Overall, CSM BIOS is a useful feature that helps to ensure compatibility and functionality across different generations of hardware and software.