What does Bios do after Booting

问题:

Does BIOS do something after booting? IO in BIOS mean input/output but isn`t bios used only when booting process? If BIOS is not used how can operating system interact with other hardware?

回答1:

Read wikipage about BIOS & booting & firmware & UEFI

With current operating systems (in particular Linux, for which you'll find a big lot of documentation & resources; notice that Linux & coreboot is free software, so you can study its source code), the BIOS is (nearly) only useful to load the boot loader (like GRUB), which later loads the Linux kernel.

In the 1980s, the BIOS was providing Basic Input Output Services (in 16 bits real mode) to the MS-DOS, hence its name. Today it is mostly legacy stuff.

The Linux kernel has a lot of device drivers interacting directly with the hardware devices (and do not need the BIOS for that)

^{NB: perhaps a tiny bit of some BIOSes are needed for ACPI, SMM, etc... Details are hardware and BIOS specific, and you should not care}

See also http://osdev.org/