Specifications

AMD Geode™ GeodeROM Functional Specification 103
System Services
32087C
12.1 INT 15h System Services Functions Descriptions
This section lists those INT 15h functions supported in GeodeROM, the parameters that system software supplies to each
INT 15h function, and the values each function returns.
12.1.1 Function 24h - A20 Support
• GeodeROM provides three subfunctions associated with A20 Gate support:
— Subfunction 00h: Disable A20 Gate
— Subfunction 01h: Enable A20 Gate
— Subfunction 02h: Get A20 Gate Status
— Subfunction 03h: A20 Support
12.1.1.1 Subfunction 00h - Disable A20 Gate
Description:
Disables the A20 functionality.
Passed:
Returns:
Related Functions:
None.
Function C1h - Get EBDA Address 155
Function C2h - PS/2 Mouse Support 156
Subfunction 00h: - Enable/Disable Pointing Device 156
Subfunction 01h - Reset Pointing Device 157
Subfunction 02h - Set Sample Rate 157
Subfunction 03h - Set Resolution 158
Subfunction 04h - Read Device Type 158
Subfunction 05h - Initialize Pointing Device Interface 159
Subfunction 06h - Pointing Device Extended Commands 159
Subfunction 07h - Set Pointing Device Handler Address 160
Function E8h - Memory Size and Map Support 160
Subfunction 01h - Get System Memory Size 160
Subfunction 20h - Get System Memory Map 161
Parameter Description
AH C0h
AL 00h
Parameter Description
CF 0 = Success
1 = Failure
AH 00h if successful
01h if keyboard is in secure mode
Table 12-1. INT 15h System Services Support Functions (Continued)
Function Subfunction Page Number