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Functions 8000_0002h, 8000_0003h, and 8000_0004h - Processor Name String

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23913A/0-November 2000 Preliminary Information Embedded AMD-K6™ Processors BIOS Design Guide Functions 8000_0002h, 8000_0003h, and 8000_0004h - Processor Name String Input: EAX = 8000_0002h, 8000_0003h, or 8000_0004h Output: EAX = Processor Name String EBX = Processor Name String ECX = Processor Name String EDX = Processor Name String Functions 8000_0002h, 8000_0003h, and 8000_0004h each return part of the processor name string in the EAX, EBX, ECX, and EDX registers. These three functions use the four registers to return an ASCII string of up to 48 characters in little endian format. For example, function 8000_0002h returns the first 16 characters of the processor name. The first character resides in the least significant byte of EAX, and the last character (of this group of 16) resides in the most significant byte of EDX. The NULL character (ASCII 00h) is used to indicate the end of the processor name string. This feature is useful for processor names that require fewer than 48 characters. Note: Extended functions 8000_0002h, 8000_0003h, and 8000_0004h return an incorrect name string for the AMD-K6-2E+ and AMD-K6-IIIE+ processors (Model D). The returned name string should be AMD-K6™-2+ for the AMD-K6-2E+ processor and AMD-K6™-III+ for the AMD-K6-IIIE+ processor. However, the actual value returned for either processor is AMD-K6™-III. The AMD CPUID utility v2.07 should be used to display the name string specified for AMD-K6E, Model D processors. This utility can be obtained from http: //www.amd.com/products/cpg/bin/amdcpuid.exe. Feature bits returned by the standard and extended function calls of the CPUID instruction should still be used to determine the features and capabilities supported by the processor in use. Appendix A 77

Section	Page
Contents	3
List of Figures	7
List of Tables	9
Revision History	11
Introduction	13
Audience	13
Processor Models and Steppings	14
AMDK6™E Embedded Processor	15
Model 7	15
AMDK6™2 Processor	15
Model 8/[7:0]	15
Model 8/[F:8]	15
AMDK6™2E Embedded Processor	16
Model 8/[F:8]	16
AMDK6™2E+ Embedded Processor	16
Model D/[7:4]	16
AMDK6™III Processor	17
Model 9/[3:0]	17
AMDK6™IIIE+ Embedded Processor	17
Model D/[3:0]	17
BIOS Consideration Checklist	18
CPUID	18
CPU Speed Detection	18
ModelSpecific Registers (MSRs)	18
Cache Testing	19
SMM Issues	19
States after RESET and INIT	20
Register States after RESET and INIT	20
Processor State after INIT	21
BuiltIn SelfTest (BIST)	22
CPUID Identification Algorithms	23
System Management Mode (SMM)	25
StateSave Map Differences	25
I/O Trap Dword Differences	25
ModelSpecific Registers Overview	26
Standard Model-Specific Registers (All Models)	28
MachineCheck Address Register (MCAR) and MachineCheck Type Register (MCTR)	28
Test Register 12 (TR12)	28
Time Stamp Counter (TSC)	28
Model 7 and Model 8/[7:0] Registers	29
Extended Feature Enable Register (EFER)	30
Write Handling Control Register (WHCR)	31
Write Allocation	31
Write Cacheability Detection Enable Bit	32
Write Allocate Enable Limit Field	32
Write Allocate Enable 15to16Mbyte Field.	33
SYSCALL/SYSRET Target Address Register (STAR)	34
Model 8/[F:8] Registers	35
Extended Feature Enable Register (EFER)	36
External Write Buffer Empty Control Field	36
Write Handling Control Register (WHCR)	39
Write Allocation	39
Write Allocate Enable Limit Field	40
Write Allocate Enable 15to16Mbyte Field	41
UC/WC Cacheability Control Register (UWCCR)	42
Physical Base Address n (n=0, 1)	43
Physical Address Mask n (n=0, 1)	43
WCn (n=0, 1)	43
UCn (n=0, 1)	43
Memory-Range Restrictions	44
Examples	45
Processor State Observability Register (PSOR)	46
NOL2 Bit	46
STEP Field	46
BF Field	46
Page Flush/Invalidate Register (PFIR)	48
LINPAGE Field	48
PF Bit	48
F/I Bit	49
Model 9 Registers	50
Extended Feature Enable Register (EFER)	51
Level-2 Cache Array Access Register (L2AAR)	52
LRU (Least Recently Used) Field	55
Writing to L2 Tag of AMDK6™III Processor	55
Model D Registers	57
Processor State Observability Register (PSOR) (Low-Power Versions)	58
PBF[2:0] Field	58
VID Field	58
NOL2 Bit	59
STEP Field	59
EBF[2:0] Field	59
Level-2 Cache Array Access Register (L2AAR)	60
LRU (Least Recently Used) Field	64
Writing to L2 Tag of AMDK6IIIE+ Processor	65
Enhanced Power Management Register (EPMR) (Low-Power Versions)	66
EPM 16-Byte I/O Block (Low-Power Versions Only)	67
BVC Field	67
Embedded AMD Processor Recognition	69
CPUID Instruction Overview	69
Testing for the CPUID Instruction	70
Illegal Instruction Exception Method	70
EFLAGS IDBit Method	70
Using CPUID Functions	71
Identifying the Processor’s Vendor	72
Testing For Extended Functions	73
Determining the Processor Signature	73
Identifying Supported Features	75
Determining Instruction Set Support	76
Detection Algorithm for Determining Instruction Set Support	77
CPUID Test	77
Standard Function Test	77
MMX™ Test	77
Optional SSE Test	77
Extended Functions Test	77
3DNow!™ Test	77
Vendor Check	77
3DNow! Extensions Test	78
AMD Multimedia Instruction Extensions Test	78
AMD Processor Signature (Extended Function)	78
Displaying the Processor’s Name	78
Displaying Cache Information	79
Determining AMDPowerNow!™ Technology Information	79
Sample Code	79
New AMDK6™ Processor Instructions	80
Additional Considerations	81
Software Timing Dependencies Relative to Memory Controller Setup	81
Pipelining Support	81
Read-Only Memory	82
Appendix A	83
CPUID	83
Standard Functions	84
Extended Functions	87
Cache Associativity Field Definitions	92
Associativity for L1 Caches and L1 TLBs	92
Associativity for L2 Cache	92
Appendix B	93
Values Returned by the CPUID Instruction	93

Match case Limit results 1 per page

Appendix A

23913A/0—November 2000

Embedded AMD-K6™ Processors BIOS Design Guide

Preliminary Information

Functions 8000_0002h, 8000_0003h, and 8000_0004h — Processor Name String

Input:

EAX = 8000_0002h, 8000_0003h, or 8000_0004h

Output:

EAX = Processor Name String

EBX = Processor Name String

ECX = Processor Name String

EDX = Processor Name String

Functions 8000_0002h, 8000_0003h, and 8000_0004h each return part of the processor

name string in the EAX, EBX, ECX, and EDX registers. These three functions use the

four registers to return an ASCII string of up to 48 characters in little endian format.

For example, function 8000_0002h returns the first 16 characters of the processor

name. The first character resides in the least significant byte of EAX, and the last

character (of this group of 16) resides in the most significant byte of EDX. The NULL

character (ASCII 00h) is used to indicate the end of the processor name string. This

feature is useful for processor names that require fewer than 48 characters.

Note:

Extended functions 8000_0002h, 8000_0003h, and 8000_0004h return an incorrect

name string for the AMD-K6-2E+ and AMD-K6-IIIE+ processors (Model D). The

returned name string should be AMD-K6™-2+ for the AMD-K6-2E+ processor and

AMD-K6™-III+ for the AMD-K6-IIIE+ processor. However, the actual value returned

for either processor is AMD-K6™-III. The AMD CPUID utility v2.07 should be used

to display the name string specified for AMD-K6E, Model D processors. This utility

can be obtained from http: //www.amd.com/products/cpg/bin/amdcpuid.exe.

Feature bits returned by the standard and extended function calls of the CPUID

instruction should still be used to determine the features and capabilities supported

by the processor in use.