TYPES OF BIOS AND THEIR CHARACTERISTICS
The BIOS (Basic Input / Output System) is a fundamental de facto standard for any PC that defines the firmware interface, is responsible for initializing and examining all the hardware components during boot, some of these devices can be the hard drive, keyboard, screen, mouse, RAM, etc.
ROM BIOS: this was one of the first BIOS is used in the decade of the 90, recorded in a non-volatile memory located on the motherboard and called ROM that guaranteed the independence of the rest of the hardware that preserved the data despite turning off the PC. Practically the Rom Bios is a software that locates and recognizes all the necessary devices to load the operative system in the RAM memory; It is a very basic software installed on the motherboard that allows it to fulfill its purpose.
Shadow BIOS: This BIOS version is loaded into the RAM memory through a process, known as “BIOS Shadowing”, which allows the BIOS to use the RAM instead of the normal ROM during the boot process of the computer, with the purpose of improving the overall performance of the PC. By processing the contents of the ROM that is being copied into the RAM, allowing the computer to access that information more quickly, it is known as a shadow BIOS. This process is also known as Shadow ROM BIOS, Shadow Memory and Shadow RAM
BIOS Flash: From the first BIOS on reprogrammable memories of type EPROM and EEPROM the natural evolution has been the last BIOS Flash, through this version it is possible to update the BIOS comfortably
PnP BIOS (PnP-aware BIOS): By definition Plug and Play BIOS is that Basic Input / Output System that allows the computer to directly and automatically recognize an external device of hardware type. These types automatically come to recognize a hardware-external device-. They are considered to be the most modern types of bios, which can easily handle the Microsoft PnP standard. With this bios it is possible to identify any type of hardware device that is connected.
BIOS EFI and UEFI: These new standards of BIOS, based on architecture of 32 bits and 64 bits, promise to drastically reduce the load time of the operating system, to support the instantaneous start and graphic interfaces more friendly for the user. It is a development carried out by Intel and that began in the early 90s to create a more efficient working environment for Itanium processors. But fortunately, it did not stop there, since UEFI is currently being implemented on most of the most modern motherboards on the market.
Coreboot and OpenBIOS: Open source initiatives related to BIOS type programs are led by Coreboot, formerly called Linux BIOS, published under the GNU GPL license and focused on 32/64-bit operating systems, and Open BIOS, an Open Firmware implementation for hardware initialization.