HP XA manual Bios Addresses, System Memory Map

4 HP BIOS

BIOS Addresses

BIOS Addresses

This section provides a summary of the main features of the HP system BIOS. This is software that provides an interface between the computer hardware and the operating system.

The procedure for updating the System ROM firmware is described on page 50.

System Memory Map

Reserved memory used by accessory boards must be located in the area from C8000h to EFFFFh.

0000 0000 - 0000 03FF		Real-mode IDT
0000 0400 - 0000 04FF		BIOS Data Area
0000 0500 - 0009 FC00		Used by OS
0009 FC00 - 0009 FFFF		Extended BIOS Data Area
000A_0000 - 000B_FFFF		Video RAM or
		SMRAM (not visible unless in SMM)
000C 0000 - 000C 7FFF		Video ROM
000C 8000 - 000F FFFF		Adapter ROM, RAM, memory-mapped registers
000E 0000 - 000F FFFF		128 KB BIOS (Flash/Shadow)1
10 0000 - FF FFFF		Memory (1 MB to 16 MB)
100 0000	- 1FF FFFF	Memory (16 MB to 32 MB)
200 0000	-3FF FFFF	Memory (32 MB to 64 MB)
400 0000	-1FFF FFFF	Memory (64 MB to 512 MB)
FFFE 0000 - FFFF FFFF		128 KB BIOS (Flash)

1.This is for Physical memory. As soon as the PST has been completed, the E000-EFFF area has to be re- leased for UMBs.

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