New <PNP0303> and aPic question

John Baldwin jhb at
Wed Nov 5 14:43:11 PST 2003

On 04-Nov-2003 Alex Wilkinson wrote:
>       On Tue, Nov 04, 2003 at 12:56:07PM -0500, John Baldwin wrote:
>       Yes.  As long as you have 'device apic' in your kernel config,
>       APICs will be used to route interrupts even on UP machines if
>       the machine includes an MP Table or ACPI is being used and it
>       contains an MADT.
> Reading thread and not following the acronyms.
> Ok 2 questions:
> 1. what is an MP Table ?

It's a table included on SMP systems built by the BIOS that lists
local APICs (CPUs) and I/O APICs as well as routing information about
what interrupts (both ISA and PCI) are hooked up to which interrupt
pins on each of the APICs.

> 2. What is MADT ?

ACPI's stripped down version of the MP Table called a Multiple Apic
Descriptor Table.  It lists local APICs and IO APICs as well as
nonstandard ISA interrupt routings.  It does not include information
about PCI interrupts.


John Baldwin <jhb at>  <><
"Power Users Use the Power to Serve!"  -

More information about the freebsd-current mailing list