AMD CS5535 User Manual

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

April 2006

Publication ID: 32430C

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

© 2006 Advanced Micro Devices, Inc. All rights reserved.

The contents of this document are provided in connection with Advanced Micro
Devices, Inc. (“AMD”) products. AMD makes no representations or warranties with
respect to the accuracy or completeness of the contents of this publication and
reserves the right to make changes to specifications and product descriptions at
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assumes no liability whatsoever, and disclaims any express or implied warranty,
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AMD’s products are not designed, intended, authorized or warranted for use as
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Other product names used in this publication are for identification purposes only and may be trademarks of their respective
companies.

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

Contents 32430C

Contents

List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1.0 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

1.2 Assumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.0 Model Specific Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.1 Example MSR Transaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3.0 GeodeLink™ Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3.1 GeodeLink™ MSR Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.2 Descriptors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4.0 Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4.1 Processor Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4.2 AMD Geode™ CS5535 Companion Device Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

4.3 Virtual System Architecture™ Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

4.4 PCI Bus Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

4.5 Miscellaneous Initializations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

5.0 Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

5.1 Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

6.0 Setup Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

7.0 Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Appendix A Support Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

A.1 Document Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

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Contents

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

List of Figures 32430C

List of Figures

Figure 3-1. GeodeLink™ Architecture Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Figure 4-1. Clock Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 7-1. GLIU Descriptor Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Figure 7-2. CPU Core Cache Descriptors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Figure 7-3. CPU Core Cache Region Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Figure 7-4. GeodeROM Flow - GX Processor/CS5535 Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

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List of Figures

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

List of Tables 32430C

List of Tables

Table 4-1. Default Region Configuration Properties Bit Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Table 4-2. Diverse Device I/O Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

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List of Tables

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

Overview 32430C

1.0Overview

1

1.1 Introduction

This document describes the changes needed for GeodeROM and other BIOSs to support the AMD Geode™ GX proces­sor 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 appro­priate, 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).

1.2 Assumption

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 ini­tialization. If a SPD is not present, GeodeROM outputs a POST code and halts, unless customizations have been made for
the platform.

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Assumption

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

Model Specific Registers 32430C

2.0Model Specific Registers

2

There are two ways to read or write Model Specific Registers (MSRs) in a Geode™ GX processor system. Software run­ning on the processor can use the RDMSR and WRMSR instructions, and modules within the processor can use the
GeodeLink™ MSR transactions. The second method allows debug modules, such as the System Navigator from FS
Silicon Solutions), to program MSRs.

All MSRs are 64 bits wide. The MSR addresses are 32 bits, where each unique address refers to a 64-bit data quantity.

To communicate with modules on the GeodeLink interface, the address of that module must be known. Addresses are
obtained by either scanning the GeodeLink interface or having prior knowledge of the chip topology. This is discussed in
detail in Section 3.0 "GeodeLink™ Architecture" on page 13.

RDMSR:

Input

ECX - Address to read.

2

(First

Output

EDX:EAX - 64 bits data returned.

WRMSR:

Input

ECX - Address to write.
EDX:EAX - 64 bits data written.

Output

None.

2.1 Example MSR Transaction

Read and write extended CPUID registers.

This example will change the CPUID.

RDMSR:

Load MSR specified by ECX into EDX:EAX.

WRMSR:

Write the value in EDX:EAX to MSR specified by ECX.

MSR_CPUID0 EQU 00003000h
MSR_CPUID1 EQU 00003001h

mov ecx, MSR_CPUID0
RDMSR ; get values
mov edx, ‘cdeR’ ; write edx:eax to MSR in ecx. No change to eax.
WRMSR

mov ecx, MSR_CPUID1
RDMSR
mov edx, ‘duol’ ; No change to eax
WRMSR
; Done

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