Specifications

238 AMD Geode™ GeodeROM Functional Specification
Virtual Hardware
32087C
16.2 Virtual RTC/CMOS
The GeodeROM SMM software can simulate an RTC/CMOS device by registering for the following two types of events at
initialization: a timer to be notified every second (1000 ms) and I/O access to 70h and 71h.
During the operation, two other timers are used for the following events: periodic interrupt and update in progress.
During POST, the date and time in the V-RTC is initialized to midnight, January 1, 1980. Other initial values are:
• Status_A = 26h
• Status_B = 02h
• Status_C = 00h
• Status_D = 80h
• All other V-CMOS locations = 00h
Note that POST initializes various “legacy” locations.