82G33 datasheet(65/437 Pages) INTEL

65 / 437 page

System Address Map

Datasheet

3.4.1

Memory Re-claim Background

The following are examples of Memory Mapped IO devices are typically located below

4 GB:

• High BIOS

• HSEG

• TSEG

• Graphics stolen

• XAPIC

• Local APIC

• FSB Interrupts

• Mbase/Mlimit

• Memory-mapped I/O space that supports only 32 B addressing

The (G)MCH provides the capability to re-claim the physical memory overlapped by

the Memory Mapped IO logical address space. The (G)MCH re-maps physical memory

from the Top of Low Memory (TOLUD) boundary up to the 4 GB boundary to an

equivalent sized logical address range located just below the Intel ME's stolen

memory.

3.4.2

Memory Reclaiming

An incoming address (referred to as a logical address) is checked to see if it falls in

the memory re-map window. The bottom of the re-map window is defined by the

value in the RECLAIMBASE register. The top of the re-map window is defined by the

value in the RECLAIMLIMIT register. An address that falls within this window is

reclaimed to the physical memory starting at the address defined by the TOLUD

can be 1 MB aligned when reclaim is disabled.

3.5

PCI Express* Configuration Address Space

There is a device 0 register, PCIEXBAR, that defines the base address for the

configuration space associated with all devices and functions that are potentially a

part of the PCI Express root complex hierarchy. The size of this range is

programmable for the (G)MCH. BIOS must assign this address range such that it will

not conflict with any other address ranges. See Chapter 6 for more details.

82G33 Datasheet(PDF) 65 Page - Intel Corporation