Chapter 8 BIOS ROM
Compaq iPAQ Family of Internet Devices
First Edition - March 2000
8-2
8.2 DESKT OP MANAGEMENT SUPPORT
Desktop Management deals with issues of security, identification, and system management
functions. Desktop Management is provided by BIOS INT 15 functions listed Table 8-1.
Table 8-1. Desktop Management Functions (INT15)
Table 8-1.
Desktop Management Functions (INT15)
AX Function Mode
E800h Get system ID Real, 16-, & 32-bit Prot.
E807h Get Sys tem Information Table Real, 16-, & 32-bit Prot.
E813h Get monitor information Real, 16-, & 32-bit Prot.
E814h Get system revision Real, 16-, & 32-bit Prot.
E816h Get temperature s tatus Real, 16-, & 32-bit Pr ot.
E817h Get drive attribut e Real
E818h Get drive off-line t est Real
E819h Get chass is serial number Real, 16-, & 32-bit Prot.
E81Ah Write chassis serial number Real
E81Bh Get drive threshold Real
E81Eh Get drive ID Real
E820h System Memor y Map Real
E822h Flash ROM/S ys. Admin. Fnc. Real, 16-, & 32-bit Prot.
E827h DIMM EEPROM Acces s Real, 16-, & 32-bit Prot.
E828h Inhibit power button Real, 16-, & 32-bit Prot.
E845h Acces s CMOS Feature Bits Real, 16-, & 32-bit Prot.
E846h Security Func tions Real, 16-, & 32-bit Prot.
All 32-bit prot ected mode calls are accessed by using the industr y-standard BIOS32 S ervice
Directory. Using t he service directory in volves three steps:
1. Locating the ser vice directory.
2. Using the service directory to obtain the entry point for the client management functions.
3. Calling the client management service to perform the desired function.
The BIOS32 S ervice Director y is a 16-byte block t hat begins on a 16-byte bounda ry between the
physical address range of 0E0000h-0FFFFFh. The format is as follows:
Offset No. Bytes Description
00h 4 Service identifier (four AS CII characters)
04h 4 Ent ry point for the BIOS32 Service Directory
08h 1 Revision level
09h 1 Length of data structur e (no. of 16-byte units)
0Ah 1 Checksum (should add up to 00h)
0Bh 5 Reserved (all 0s)