AMD CS5535 manual Overview1, Introduction

Page 9

Overview	32430C

Overview1

1.1Introduction

This document describes the changes needed for GeodeROM and other BIOSs to support the AMD Geode™ GX proces- sor and the AMD Geode™ CS5535 companion device. GeodeROM requires modifications for hardware initialization and specific implementations.

Each section targets the GeodeROM changes needed to support the GX processor/CS5535 device system. Where appro- priate, the changes list the “Entry Conditions” that briefly describe the machine state required to execute that function, as well as some pseudo code for implementing the changes.

For more information on GeodeROM, see the AMD Geode™ GeodeROM Functional Specification (publication ID 32087).

1.2Assumption

The following assumption must be made clear during the design phase:

GeodeROM expects all memory has a serial presence detect (SPD) to determine characteristics for memory controller ini- tialization. If a SPD is not present, GeodeROM outputs a POST code and halts, unless customizations have been made for the platform.

AMD Geode™ GX Processor/CS5535 Companion Device GeodeROM Porting Guide

9

Image 9

Contents Publication ID 32430C AprilTrademarks Advanced Micro Devices, Inc. All rights reservedContents Contents GeodeLink Architecture Topology List of FiguresList of Figures List of Tables List of Tables Introduction Overview1Assumption Example MSR Transaction Model Specific Registers2Load MSR specified by ECX into Edxeax Write the value in Edxeax to MSR specified by ECXModel Specific Registers AMD Geode GeodeLink Architecture3GX Processor CS5535 Companion DeviceDescriptors GeodeLink MSR AddressingAddressing Example Memory Descriptor TypesProcessor Initialization Set Clocks and ResetSysref Mdiv VdivCalculating Processor Speed Memory Controller InitializationCPU Identification Test Extended Dram GeodeLink Modules InitializationSize Memory Default Region Configuration Properties Bit Descriptions Glpci Regions Descriptor AllocationDescriptor MSR Address Chipset ID AMD Geode CS5535 Companion Device InitializationSet ID Select Idsel Gliu InitializationIRQ Mapper Multi Function General Purpose Timers MFGPTsKeyboard Emulation Logic KEL 1+ System Management Bus SMBusAcpi Power Management LogicFlash Interface Other Legacy DD InitializationATA-5 / Hard Drive Initialization Diverse Device I/O LocationsUniversal Serial Bus USB 7 AC97 Audio Controller InitializationPCI Bus Initialization Virtual System Architecture InitializationGeodeLink Control Processor Initialization Allocate Processor Frame Buffer and VSA2 MemoryInitialize Graphics Subsystem Miscellaneous InitializationsMonochrome Support Dual Monitor Support32430C Clocking Implementation5Scratchpad Initialization Post CodesImplementation Setup Options6 32430C Memory7Map ROMVSA Memory Mapped Frame BufferVSA PCI GeodeROM Flow GX Processor/CS5535 Device VSA Table A-1. Revision History Document Revision HistoryRevision # Revisions / Comments Initial release