[coreboot] About Paging, Realmode and what is going on

[Peter Stuge]

Julius Werner wrote:
> while the program was running it mostly interacted with the BIOS directly.

Not in general - that is/was highly dependent on the program.

BIOS interrupt services offer a hardware abstraction, but they come
at a (high! interrupts are very expensive!) cost.

For anything performance sensitive, e.g. games, multitasking environments
(DESQview, Windows) or terminal emulators communicating via serial ports
which may or may not have a FIFO, the BIOS overhead is simply unacceptable.

Such programs instead interacted directly with the hardware, having
implemented drivers for some graphics and sound cards, UARTs etc.

Even the mouse BIOS interrupt services are pretty much unusable for
anything serious.


//Peter