BIOS

lastmod 2024-11-07created 2016-05-1410 edits

BIOS (Basic Input/Output System), in the broad sense, refers to the program among those built into a computer that handles input and output with the hardware at the lowest level. In the narrow sense, it refers to the one built into IBM PC compatibles, and it is usually used in this sense. BIOS is a kind of firmware, sitting between hardware and software in a computer. It performs a function like the human nervous system, such as letting most software control the hardware and passing information changed or generated by the hardware to software for processing.

Sample

BIOS entry keys by manufacturer

MBR

The boot information is contained from the first byte sector to the last sector of 512 bytes of the top partition of the first-priority boot drive. The boot information consists of boot code + partition table information + signature, and because of the structural limits of MBR, only up to 4 primary partitions can be created. Beyond that, you must partition with logical disks, and if a single drive is larger than 2.2TB, the capacity beyond that is not recognized or is recognized incorrectly.

Unlike systems combining EFI and GPT, with MBR the boot stage begins only after the BIOS has fully loaded, and then the first sector of the first partition of the top boot drive is read. If the MBR is damaged during this process, the first sector of the next primary partition is read; if there are no more primary partitions, or if the boot information cannot be loaded even after reading up to the 4th primary partition, the system does not boot.

See also

• CMOS
• ROM
• EFI (UEFI)
• Single-root input/output virtualization (SR-IOV)
• Baseboard Management Controller (BMC)

Favorite site

• Wikipedia (en) BIOS
• Namuwiki: BIOS
• BIOS : Navercast
• Do you know the difference between CMOS and BIOS?