Specifications

AMD Geode™ GeodeROM Functional Specification 15
Overview
32087C
SMI (System Management Interrupt)-Based Memory Access Capability
An SMI handler feature useful for debugging in unfamiliar or highly protected environments has the ability to read or
write addressable locations in the system. This is done through a virtual register access.
VSA2 Software Initialization
Contains sequences of code to decompress, load, and invoke the SMI handler. These sequences also initialize SMI-
specific registers, such as SMAR (System Management Address Register) SMHR (System Management Header
Register) and GX_BASE. Each is required for successful initialization of the VSA2 software.
Summary Screen
Displays a summary of vital system information (such as hardware found, CPU revision and speed, memory size,
etc.) immediately before starting the operating system.
SuperI/O Device Initialization
The SuperI/O device initialization portion of GeodeROM is a platform-dependent module that initializes the traditional
ISA bus components that reside in the SuperI/O device. For example, in a system that contains National’s PC97317
SuperI/O, this portion of the GeodeROM code configures and assigns resources to the floppy disk controller, serial
COM ports, parallel LPT port, and 8042 keyboard controller.
Text-Based Configuration Utility
The GeodeROM build process includes a series of questions to which the system designer provides information
about the board wiring, options to install, and generally how GeodeROM should behave. The tool runs automatically
the first time the build process takes place and on subsequent builds uses the information from a saved option file
(XPRESCFG.OPT).
Virtual Real-Time Clock and CMOS
The real-time clock (RTC) VSM (VSA2 Modular Component) simulates an RTC, including CMOS for platforms or
designs that do not provide a hardware RTC. While the CMOS and clock states cannot be maintained across a power
loss, a system designer may elect to forego a physical RTC, still allowing many types of software to run effectively.
Virtual UART
The UART VSM simulates the functionality of one or more UARTs. The module provides the look and feel of a stan-
dard UART, and has the flexibility for delivering or retrieving data from some hardware sources (e.g., an on-board
microcontroller).
CMOS Setup
GeodeROM setup provides a configurable engine for configuring a target platform.