Справочник Пользователя для HP A2Y15AV
Processor Configuration Registers
20
Datasheet, Volume 2
2.3.1.1
DOS Range (0h–9_FFFFh)
The DOS area is 640 KB (0000_0000h–0009_FFFFh) in size and is always mapped to
the main memory controlled by the memory controller.
the main memory controlled by the memory controller.
2.3.1.2
Legacy Video Area (A_0000h–B_FFFFh)
The legacy 128 KB VGA memory range, frame buffer, (000A_0000h–000B_FFFFh) can
be mapped to IGD (Device 2), to PCI Express (Device 1 or Device 6), and/or to the DMI
Interface. The appropriate mapping depends on which devices are enabled and the
programming of the VGA steering bits. Based on the VGA steering bits, priority for VGA
mapping is constant. The processor always decodes internally mapped devices first.
be mapped to IGD (Device 2), to PCI Express (Device 1 or Device 6), and/or to the DMI
Interface. The appropriate mapping depends on which devices are enabled and the
programming of the VGA steering bits. Based on the VGA steering bits, priority for VGA
mapping is constant. The processor always decodes internally mapped devices first.
Non-SMM-mode processor accesses to this range are considered to be to the Video
Buffer Area as described above.
Buffer Area as described above.
The processor always positively decodes internally mapped devices, namely the IGD
and PCI Express. Subsequent decoding of regions mapped to PCI Express or the DMI
Interface depends on the Legacy VGA configuration bits (VGA Enable & MDAP). This
region is also the default for SMM space.
and PCI Express. Subsequent decoding of regions mapped to PCI Express or the DMI
Interface depends on the Legacy VGA configuration bits (VGA Enable & MDAP). This
region is also the default for SMM space.
Figure 2-2. DOS Legacy Address Range
Expansion Area
128 KB (16KBx8)
000C_0000h
000D_FFFFh
896 KB
Extended System BIOS (Lower)
64 KB (16KBx4)
000E_0000h
000E_FFFFh
960 KB
Legacy Video Area
(SMM Memory)
128 KB
000A_0000h
000B_FFFFh
768 KB
DOS Area
0000_0000h
0009_FFFFh
640 KB
System BIOS (Upper)
64 KB
000F_0000h
000F_FFFFh
1 MB