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Preconfigured controllers

Posted: Fri Nov 24, 2006 5:17 am
by muisei
Brendan wrote:
For backwards compatibility purposes, the ATA/IDE controller is pre-configured by the BIOS to look and behave like a standard ISA ATA/IDE controller.
What other controllers are also preconfigured by the BIOS?

Re: Preconfigured controllers

Posted: Fri Nov 24, 2006 7:03 am
by Brendan
Hi,
muisei wrote:What other controllers are also preconfigured by the BIOS?
A quick list:
  • - PIC
    - PIT
    - PS/2 keyboard
    - Primary IDE/ATA controller
    - Secondary IDE/ATA controller
    - SCSI controller (if present)
    - Floppy disk controller
    - First video card
Of course "pre-configured" means "configured for legacy mode/DOS", and shouldn't be confused with "configured for a real OS"....

Also, ISA Plug & Play devices and PCI devices should have resources assigned to them by the BIOS. For example, even though a second video card may not be initialised, the BIOS should have memory mapped it somewhere and given it some I/O ports to use.

There's also other things, like the chipset (RAM, addressing holes, power management) and the CPU/s (MTRRs, some MSRs, SMM).


Cheers,

Brendan