Intel IA-32

Vol. 3A 3-17

PROTECTED-MODE MEMORY MANAGEMENT

3.5 SYSTEM DESCRIPTOR TYPES

When the S (descriptor type) flag in a segment descriptor is clear, the descriptor type is a system

descriptor. The processor recognizes the following types of system descriptors:

•Local descriptor-table (LDT) segment descriptor.

•Task-state segment (TSS) descriptor.

•Call-gate descriptor.

•Interrupt-gate descriptor.

•Trap-gate descriptor.

•Task-gate descriptor.

These descriptor types fall into two categories: system-segment descriptors and gate descriptors.

System-segment descriptors point to system segments (LDT and TSS segments). Gate descrip-

tors are in themselves “gates,” which hold pointers to procedure entry points in code segments

(call, interrupt, and trap gates) or which hold segment selectors for TSS’s (task gates).

Table 3-2 shows the encoding of the type field for system-segment descriptors and gate descrip-

tors. Note that system descriptors in IA-32e mode are 16 bytes instead of 8 bytes.

Table 3-2. System-Segment and Gate-Descriptor Types

Type Field Description

Decimal 11 10 9 8 32-Bit Mode IA-32e Mode

0 0000Reserved Upper 8 byte of an 16-byte

descriptor

1 000116-bit TSS (Available) Reserved

2 0010LDT LDT

3 001116-bit TSS (Busy) Reserved

4 010016-bit Call Gate Reserved

5 0101Task Gate Reserved

6 011016-bit Interrupt Gate Reserved

7 011116-bit Trap Gate Reserved

8 1000Reserved Reserved

9 100132-bit TSS (Available) 64-bit TSS (Available)

10 1010Reserved Reserved

11 101132-bit TSS (Busy) 64-bit TSS (Busy)

12 110032-bit Call Gate 64-bit Call Gate

13 1101Reserved Reserved

14 111032-bit Interrupt Gate 64-bit Interrupt Gate

15 111132-bit Trap Gate 64-bit Trap Gate

Contents

Main Page CONTENTS FOR VOLUME 3A AND 3B Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page FIGURES Page Page Page TABLES Page Page Page Page Page Page CHAPTER 1 ABOUT THIS MANUAL 1.1 IA-32 PROCESSORS COVERED IN THIS MANUAL 1.2 OVERVIEW OF THE SYSTEM PROGRAMMING GUIDE Page 1.3 NOTATIONAL CONVENTIONS 1.3.1 Bit and Byte Order 1.3.2 Reserved Bits and Software Compatibility 1.3.3 Instruction Operands 1.3.4 Hexadecimal and Binary Numbers 1.3.5 Segmented Addressing 1.3.6 Syntax for CPUID, CR, and MSR Values 1.3.7 Exceptions Page Page Page Page CHAPTER 2 SYSTEM ARCHITECTURE OVERVIEW Page Figure 2-1. IA-32 System-Level Registers and Data Structures Figure 2-2. System-Level Registers and Data Structures in IA-32e Mode 2.1.1 Global and Local Descriptor Tables 2.1.2 System Segments, Segment Descriptors, and Gates 2.1.3 Task-State Segments and Task Gates 2.1.4 Interrupt and Exception Handling 2.1.5 Memory Management 2.1.6 System Registers 2.2 MODES OF OPERATION System Management Mode 2.3 SYSTEM FLAGS AND FIELDS IN THE EFLAGS REGISTER Page 2.3.1 System Flags and Fields in IA-32e Mode 2.4 MEMORY-MANAGEMENT REGISTERS 2.4.1 Global Descriptor Table Register (GDTR) 2.4.2 Local Descriptor Table Register (LDTR) 2.4.3 IDTR Interrupt Descriptor Table Register 2.4.4 Task Register (TR) 2.5 CONTROL REGISTERS 2-18 Vol. 3A Page-Directory Base (PDBR) Figure 2-6. Control Registers CR1 Page-Fault Linear Address CR2 CR4 Page Page Page Page Page 2.5.1 CPUID Qualification of Control Register Flags 2.6 SYSTEM INSTRUCTION SUMMARY 2.6.1 Loading and Storing System Registers 2.6.2 Verifying of Access Privileges 2.6.3 Loading and Storing Debug Registers 2.6.4 Invalidating Caches and TLBs 2.6.5 Controlling the Processor 2.6.6 Reading Performance-Monitoring and Time-Stamp Counters 2.6.7 Reading and Writing Model-Specific Registers Page Page Page CHAPTER 3 PROTECTED-MODE MEMORY MANAGEMENT 3.1 MEMORY MANAGEMENT OVERVIEW Page 3.2 USING SEGMENTS 3.2.1 Basic Flat Model 3.2.2 Protected Flat Model Figure 3-2. Flat Model Figure 3-3. Protected Flat Model 3.2.3 Multi-Segment Model 3.2.4 Segmentation in IA-32e Mode 3.2.5 Paging and Segmentation 3.3 PHYSICAL ADDRESS SPACE 3.3.1 Physical Address Space for Processors with Intel EM64T 3.4 LOGICAL AND LINEAR ADDRESSES 3.4.1 Logical Address Translation in IA-32e Mode 3.4.2 Segment Selectors 3.4.3 Segment Registers Page 3.4.4 Segment Loading Instructions in IA-32e Mode 3.4.5 Segment Descriptors Page Page Table 3-1. Code- and Data-Segment Types Page 3.5 SYSTEM DESCRIPTOR TYPES 3.5.1 Segment Descriptor Tables Figure 3-10. Global and Local Descriptor Tables Page 3.5.2 Segment Descriptor Tables in IA-32e Mode 3.6 PAGING (VIRTUAL MEMORY) OVERVIEW 3.6.1 Paging Options 3.6.2 Page Tables and Directories in the Absence of Intel EM64T 3.7.1 Linear Address Translation (4-KByte Pages) Figure 3-12. Linear Address Translation (4-KByte Pages) Table 3-3. Page Sizes and Physical Address Sizes 3.7.2 Linear Address Translation (4-MByte Pages) 3.7.3 Mixing 4-KByte and 4-MByte Pages 3.7.4 Memory Aliasing 3.7.5 Base Address of the Page Directory 3.7.6 Page-Directory and Page-Table Entries Page Page Page 3.7.7 Not Present Page-Directory and Page-Table Entries 3.8 36-BIT PHYSICAL ADDRESSING USING THE PAE PAGING MECHANISM 3.8.1 Enhanced Legacy PAE Paging 3.8.2 Linear Address Translation With PAE Enabled (4-KByte Pages) 3.8.3 Linear Address Translation With PAE Enabled (2-MByte Pages) 3.8.4 Accessing the Full Extended Physical Address Space With the Extended Page-Table Structure Page Vol. 3A 3-35 Page-Directory Entry (4-KByte Page Table) Page-Table Base Address Page-Table Entry (4-KByte Page) Page 3.9 36-BIT PHYSICAL ADDRESSING USING THE PSE-36 PAGING MECHANISM Figure 3-22. Linear Address Translation (4-MByte Pages) Figure 3-23. Format of Page-Directory Entries for 4-MByte Pages and 36-Bit Physical Addresses 3.10 PAE-ENABLED PAGING IN IA-32E MODE 3.10.1 IA-32e Mode Linear Address Translation (4-KByte Pages) 3.10.2 IA-32e Mode Linear Address Translation (2-MByte Pages) 3.10.3 Enhanced Paging Data Structures 3-42 Vol. 3A Figure 3-26. Format of Paging Structure Entries for 4-KByte Pages in IA-32e Mode levels. Page-Directory Entry (4-KByte Page Table) Page-Table Base Address Page-Table Entry (4-KByte Page) Table 3-4. Reserved Bit Checking When Execute Disable Bit is Disabled Table 3-5. Reserved Bit Checking When Execute Disable Bit is Enabled 3.11 MAPPING SEGMENTS TO PAGES 3.12 TRANSLATION LOOKASIDE BUFFERS (TLBS) Page Page Page CHAPTER 4 PROTECTION 4.1 ENABLING AND DISABLING SEGMENT AND PAGE PROTECTION Page PROTECTION Figure 4-1. Descriptor Fields Used for Protection 4.2.1 Code Segment Descriptor in 64-bit Mode 4.3 LIMIT CHECKING 4.3.1 Limit Checking in 64-bit Mode 4.4 TYPE CHECKING Page 4.4.1 Null Segment Selector Checking 4.5 PRIVILEGE LEVELS Page Page 4.6 PRIVILEGE LEVEL CHECKING WHEN ACCESSING DATA SEGMENTS Page 4.6.1 Accessing Data in Code Segments 4.7 PRIVILEGE LEVEL CHECKING WHEN LOADING THE SS REGISTER 4.8 PRIVILEGE LEVEL CHECKING WHEN TRANSFERRING PROGRAM CONTROL BETWEEN CODE SEGMENTS 4.8.1 Direct Calls or Jumps to Code Segments Page Page 4.8.2 Gate Descriptors 4.8.3 Call Gates Page Page PROTECTION Figure 4-10. Call-Gate Mechanism Figure 4-11. Privilege Check for Control Transfer with Call Gate Page 4.8.5 Stack Switching Page 4.8.6 Returning from a Called Procedure Page 4.8.7 Performing Fast Calls to System Procedures with the SYSENTER and SYSEXIT Instructions Page Page Page 4.10.1 Checking Access Rights (LAR Instruction) 4.10.2 Checking Read/Write Rights (VERR and VERW Instructions) 4.10.3 Checking That the Pointer Offset Is Within Limits (LSL Instruction) 4.10.4 Checking Caller Access Privileges (ARPL Instruction) Page 4.10.5 Checking Alignment 4.11 PAGE-LEVEL PROTECTION 4.11.1 Page-Protection Flags 4.11.2 Restricting Addressable Domain 4.11.3 Page Type 4.12 COMBINING PAGE AND SEGMENT PROTECTION 4.13 PAGE-LEVEL PROTECTION AND EXECUTE-DISABLE BIT 4.13.1 Detecting and Enabling the Execute-Disable Bit Capability 4.13.2 Execute-Disable Bit Page Protection Page 4.13.3 Reserved Bit Checking 4.13.4 Exception Handling Page Page CHAPTER 5 INTERRUPT AND EXCEPTION HANDLING 5.1 INTERRUPT AND EXCEPTION OVERVIEW 5.2 EXCEPTION AND INTERRUPT VECTORS 5.3 SOURCES OF INTERRUPTS 5.3.1 External Interrupts Table 5-1. Protected-Mode Exceptions and Interrupts 5.3.2 Maskable Hardware Interrupts 5.3.3 Software-Generated Interrupts 5.4 SOURCES OF EXCEPTIONS 5.4.1 Program-Error Exceptions 5.4.2 Software-Generated Exceptions 5.4.3 Machine-Check Exceptions 5.5 EXCEPTION CLASSIFICATIONS Page 5.7 NONMASKABLE INTERRUPT (NMI) 5.7.1 Handling Multiple NMIs 5.8 ENABLING AND DISABLING INTERRUPTS 5.8.1 Masking Maskable Hardware Interrupts 5.8.2 Masking Instruction Breakpoints 5.8.3 Masking Exceptions and Interrupts When Switching Stacks 5.9 PRIORITY AMONG SIMULTANEOUS EXCEPTIONS AND INTERRUPTS Table 5-2. Priority Among Simultaneous Exceptions and Interrupts 5.10 INTERRUPT DESCRIPTOR TABLE (IDT) + 5.11 IDT DESCRIPTORS 5.12 EXCEPTION AND INTERRUPT HANDLING Figure 5-2. IDT Gate Descriptors 5.12.1 Exception- or Interrupt-Handler Procedures Page Page Page 5.12.2 Interrupt Tasks Figure 5-5. Interrupt Task Switch 5.13 ERROR CODE 5.14 EXCEPTION AND INTERRUPT HANDLING IN 64-BIT MODE 5.14.1 64-Bit Mode IDT 5.14.2 64-Bit Mode Stack Frame 5.14.3 IRET in IA-32e Mode 5.14.4 Stack Switching in IA-32e Mode 5.14.5 Interrupt Stack Table 5.15 EXCEPTION AND INTERRUPT REFERENCE Interrupt 0Divide Error Exception (#DE) Interrupt 1Debug Exception (#DB) Interrupt 2NMI Interrupt Interrupt 3Breakpoint Exception (#BP) Interrupt 4Overflow Exception (#OF) Interrupt 5BOUND Range Exceeded Exception (#BR) Page Page Interrupt 7Device Not Available Exception (#NM) Page Interrupt 8Double Fault Exception (#DF) Page Interrupt 9Coprocessor Segment Overrun Interrupt 10Invalid TSS Exception (#TS) Table 5-6. Invalid TSS Conditions Page Page Interrupt 11Segment Not Present (#NP) Page Interrupt 12Stack Fault Exception (#SS) Page Page Page Page Page Interrupt 14Page-Fault Exception (#PF) Page Page Interrupt 16x87 FPU Floating-Point Error (#MF) Page Interrupt 17Alignment Check Exception (#AC) Page Interrupt 18Machine-Check Exception (#MC) Page Interrupt 19SIMD Floating-Point Exception (#XF) Page Page Interrupts 32 to 255User Defined Interrupts Page Page CHAPTER 6 TASK MANAGEMENT 6.1 TASK MANAGEMENT OVERVIEW 6.1.1 Task Structure Page 6.1.3 Executing a Task Page Figure 6-2. 32-Bit Task-State Segment (TSS) registers prior to the task switch. and EDI registers prior to the task switch. 6.2.2 TSS Descriptor 6.2.3 TSS Descriptor in 64-bit mode 6.2.4 Task Register Figure 6-4. Format of TSS and LDT Descriptors in 64-bit Mode Page 6.2.5 Task-Gate Descriptor Page Page Page Page 6.4 TASK LINKING Figure 6-8. Nested Tasks Table 6-2. Effect of a Task Switch on Busy Flag, NT Flag, Previous Task Link Field, and TS Flag 6.4.1 Use of Busy Flag To Prevent Recursive Task Switching 6.4.2 Modifying Task Linkages 6.5 TASK ADDRESS SPACE 6.5.1 Mapping Tasks to the Linear and Physical Address Spaces 6.5.2 Task Logical Address Space Page Figure 6-10. 16-Bit TSS Format Page Figure 6-11. 64-Bit TSS Format Page Page CHAPTER 7 MULTIPLE-PROCESSOR MANAGEMENT 7.1 LOCKED ATOMIC OPERATIONS 7.1.1 Guaranteed Atomic Operations 7.1.2 Bus Locking Page 7.1.3 Handling Self- and Cross-Modifying Code 7.1.4 Effects of a LOCK Operation on Internal Processor Caches 7.2 MEMORY ORDERING 7.2.1 Memory Ordering in the Intel Pentium and Intel486 7.2.2 Memory Ordering Pentium 4, Intel Xeon, and P6 Family 7.2.3 Out-of-Order Stores For String Operations in Pentium 4, Intel Xeon, and P6 Family Processors 7.2.4 Strengthening or Weakening the Memory Ordering Model Page 7.3 PROPAGATION OF PAGE TABLE AND PAGE DIRECTORY ENTRY CHANGES TO MULTIPLE PROCESSORS 7.4 SERIALIZING INSTRUCTIONS 7.5 MULTIPLE-PROCESSOR (MP) INITIALIZATION 7.5.1 BSP and AP Processors 7.5.2 MP Initialization Protocol Requirements and Restrictions for Intel Xeon Processors 7.5.3 MP Initialization Protocol Algorithm for Intel Xeon Processors Page Page Page 7.5.5 Identifying Logical Processors in an MP System 7.6 HYPER-THREADING AND MULTI-CORE TECHNOLOGY 7.7 DETECTING HARDWARE MULTI-THREADING SUPPORT AND TOPOLOGY 7.7.1 Initializing IA-32 Processors Supporting Hyper-Threading Technology 7.7.2 Initializing Dual-Core IA-32 Processors 7.7.3 Executing Multiple Threads on an IA-32 Processor Supporting Hardware Multi-Threading 7.7.4 Handling Interrupts on an IA-32 Processor Supporting Hardware Multi-Threading MULTIPLE-PROCESSOR MANAGEMENT Figure 7-3. Local APICs and I/O APIC in MP System Supporting HT Technology 7.8 INTEL HYPER-THREADING TECHNOLOGY ARCHITECTURE Page Page 7.8.4 Page Attribute Table (PAT) 7.8.5 Machine Check Architecture 7.8.6 Debug Registers and Extensions 7.8.7 Performance Monitoring Counters 7.8.8 IA32_MISC_ENABLE MSR 7.8.9 Memory Ordering 7.8.10 Serializing Instructions 7.8.11 MICROCODE UPDATE Resources 7.8.12 Self Modifying Code Page 7.9 DUAL-CORE ARCHITECTURE 7.9.1 Logical Processor Support 7.9.2 Memory Type Range Registers (MTRR) 7.9.3 Performance Monitoring Counters 7.9.4 IA32_MISC_ENABLE MSR 7.9.5 MICROCODE UPDATE Resources 7.10 PROGRAMMING CONSIDERATIONS FOR HARDWARE MULTI-THREADING CAPABLE PROCESSORS 7.10.2 Identifying Logical Processors in an MP System MULTIPLE-PROCESSOR MANAGEMENT 7.10.3 Algorithm for Three-Level Mappings of APIC_ID Page Page 7.10.4 Identifying Topological Relationships in a MP System Page Page Page 7.11 MANAGEMENT OF IDLE AND BLOCKED CONDITIONS 7.11.1 HLT Instruction 7.11.2 PAUSE Instruction 7.11.3 Detecting Support MONITOR/MWAIT Instruction 7.11.4 MONITOR/MWAIT Instruction 7.11.5 Monitor/Mwait Address Range Determination 7.11.6 Required Operating System Support Page Page Page Page Page Page CHAPTER 8 ADVANCED PROGRAMMABLE INTERRUPT CONTROLLER (APIC) 8.1 LOCAL AND I/O APIC OVERVIEW Page Page Page 8.2 SYSTEM BUS VS. APIC BUS 8.3 THE INTEL 82489DX EXTERNAL APIC, THE APIC, AND THE XAPIC 8.4 LOCAL APIC 8.4.1 The Local APIC Block Diagram Figure 8-4. Local APIC Structure Page 8.4.2 Presence of the Local APIC Table 8-1. Local APIC Register Address Map (Contd.) 8.4.3 Enabling or Disabling the Local APIC 8.4.4 Local APIC Status and Location 8.4.5 Relocating the Local APIC Registers 8.4.6 Local APIC ID 8.4.7 Local APIC State Page 8.4.8 Local APIC Version Register 8.5 HANDLING LOCAL INTERRUPTS 8.5.1 Local Vector Table Figure 8-8. Local Vector Table (LVT) Page 8.5.2 Valid Interrupt Vectors 8.5.3 Error Handling 8.5.4 APIC Timer Page 8.5.5 Local Interrupt Acceptance 8.6 ISSUING INTERPROCESSOR INTERRUPTS 8.6.1 Interrupt Command Register (ICR) Page Page Page Page Table 8-4. Valid Combinations for the P6 Family Processors Local APIC Interrupt Command Register 8.6.2 Determining IPI Destination Page Page Page 8.6.3 IPI Delivery and Acceptance 8.7 SYSTEM AND APIC BUS ARBITRATION 8.8 HANDLING INTERRUPTS 8.8.1 Interrupt Handling with the Pentium 4 and Intel Xeon 8.8.2 Interrupt Handling with the P6 Family and Pentium Vol. 3A 8-35 Figure 8-17. Interrupt Acceptance Flow Chart for the Local APIC (P6 Family and Pentium Processors) 8.8.3 Interrupt, Task, and Processor Priority Page 8.8.4 Interrupt Acceptance for Fixed Interrupts Page 8.8.5 Signaling Interrupt Servicing Completion 8.8.6 Task Priority in IA-32e Mode 8.9 SPURIOUS INTERRUPT Page 8.10 APIC BUS MESSAGE PASSING MECHANISM AND PROTOCOL (P6 FAMILY, PENTIUM PROCESSORS) 8.10.1 Bus Message Formats 8.11 MESSAGE SIGNALLED INTERRUPTS 8.11.1 Message Address Register Format 8.11.2 Message Data Register Format Page Page Page Page Page CHAPTER 9 PROCESSOR MANAGEMENT AND INITIALIZATION 9.1 INITIALIZATION OVERVIEW 9.1.1 Processor State After Reset 9.1.2 Processor Built-In Self-Test (BIST) Table 9-1. IA-32 Processor States Following Power-up, Reset, or INIT Table 9-1. IA-32 Processor States Following Power-up, Reset, or INIT (Contd.) 9.1.3 Model and Stepping Information Figure 9-2. Version Information in the EDX Register after Reset Figure 9-1. Contents of CR0 Register after Reset 9.1.4 First Instruction Executed 9.2 X87 FPU INITIALIZATION 9.2.1 Configuring the x87 FPU Environment 9.2.2 Setting the Processor for x87 FPU Software Emulation 9.3 CACHE ENABLING 9.4 MODEL-SPECIFIC REGISTERS (MSRS) 9.5 MEMORY TYPE RANGE REGISTERS (MTRRS) 9.6 INITIALIZING SSE/SSE2/SSE3 EXTENSIONS 9.7 SOFTWARE INITIALIZATION FOR REAL-ADDRESS MODE OPERATION 9.7.1 Real-Address Mode IDT 9.7.2 NMI Interrupt Handling 9.8 SOFTWARE INITIALIZATION FOR PROTECTED-MODE OPERATION 9.8.1 Protected-Mode System Data Structures 9.8.2 Initializing Protected-Mode Exceptions and Interrupts 9.8.3 Initializing Paging 9.8.4 Initializing Multitasking 9.8.5 Initializing IA-32e Mode 9.9 MODE SWITCHING 9.9.1 Switching to Protected Mode 9.9.2 Switching Back to Real-Address Mode Page 9.10 INITIALIZATION AND MODE SWITCHING EXAMPLE Page 9.10.1 Assembler Usage 9.10.2 STARTUP.ASM Listing Page Page Page Page Page Page Page Figure 9-5. Moving the GDT, IDT, and TSS from ROM to RAM (Lines 196-261 of List File) Figure 9-6. Task Switching (Lines 282-296 of List File) 9.10.3 MAIN.ASM Source Code 9.10.4 Supporting Files Table 9-5 shows the relationship of each build item with an ASM source file. 9.11 MICROCODE UPDATE FACILITIES Table 9-5. Relationship Between BLD Item and ASM Source File 9.11.1 Microcode Update . Table 9-6. Microcode Update Field Definitions (Contd.) Table 9-7. Microcode Update Format Table 9-6. Microcode Update Field Definitions (Contd.) 9.11.2 Optional Extended Signature Table 9.11.3 Processor Identification 9.11.4 Platform Identification 9.11.5 Microcode Update Checksum 9.11.6 Microcode Update Loader 9.11.7 Update Signature and Verification Page Page 9.11.8 Pentium 4, Intel Xeon, and P6 Family Processor Microcode Update Specifications Page Page Page Table 9-12. Microcode Update Functions Page Page Page Page Figure 9-8. Microcode Update Write Operation Flow [1] Vol. 3A 9-59 Figure 9-9. Microcode Update Write Operation Flow [2] 9-60 Vol. 3A Page Table 9-17. Parameters for the Read Microcode Update Data Function Page Page Page Page CHAPTER 10 MEMORY CACHE CONTROL 10.1 INTERNAL CACHES, TLBS, AND BUFFERS Page Page 10.2 CACHING TERMINOLOGY 10.3 METHODS OF CACHING AVAILABLE Page Page 10.3.1 Buffering of Write Combining Memory Locations 10.3.2 Choosing a Memory Type 10.4 CACHE CONTROL PROTOCOL 10.5 CACHE CONTROL 10.5.1 Cache Control Registers and Bits Figure 10-2. Cache-Control Registers and Bits Available in IA-32 Processors Table 10-5. Cache Operating Modes Page 10.5.2 Precedence of Cache Controls Page Page 10.5.3 Preventing Caching 10.5.4 Disabling and Enabling the L3 Cache 10.5.5 Cache Management Instructions 10.5.6 L1 Data Cache Context Mode 10.6 SELF-MODIFYING CODE 10.7 IMPLICIT CACHING (PENTIUM 4, INTEL XEON, AND P6 FAMILY PROCESSORS) 10.8 EXPLICIT CACHING 10.9 INVALIDATING THE TRANSLATION LOOKASIDE BUFFERS (TLBS) 10.10 STORE BUFFER 10.11 MEMORY TYPE RANGE REGISTERS (MTRRS) Page 10.11.1 MTRR Feature Identification 10.11.2 Setting Memory Ranges with MTRRs Page Figure 10-6 shows flags and fields in these registers. The functions of these flags and fields are: for the encoding of this field). Table 10-9. Address Mapping for Fixed-Range MTRRs Page Page 10.11.3 Example Base and Mask Calculations Page 10.11.4 Range Size and Alignment Requirement 10.11.5 MTRR Initialization 10.11.6 Remapping Memory Types 10.11.7 MTRR Maintenance Programming Interface Page Page 10.11.8 MTRR Considerations in MP Systems 10.11.9 Large Page Size Considerations 10.12 PAGE ATTRIBUTE TABLE (PAT) 10.12.1 Detecting Support for the PAT Feature 10.12.2 IA32_CR_PAT MSR 10.12.3 Selecting a Memory Type from the PAT 10.12.4 Programming the PAT Page 10.12.5 PAT Compatibility with Earlier IA-32 Processors Page Page Page CHAPTER 11 INTEL MMX TECHNOLOGY SYSTEM PROGRAMMING 11.1 EMULATION OF THE MMX INSTRUCTION SET 11.2 THE MMX STATE AND MMX REGISTER ALIASING Page 11.2.1 Effect of MMX, x87 FPU, FXSAVE, and FXRSTOR Instructions on the x87 FPU Tag Word 11.3 SAVING AND RESTORING THE MMX STATE AND REGISTERS 11.4 SAVING MMX STATE ON TASK OR CONTEXT SWITCHES 11.5. EXCEPTIONS THAT CAN OCCUR WHEN EXECUTING MMX INSTRUCTIONS 11.5.1 Effect of MMX Instructions on Pending x87 Floating-Point Exceptions 11.6 DEBUGGING MMX CODE INTEL MMX TECHNOLOGY SYSTEM PROGRAMMING Figure 11-2. Mapping of MMX Registers to x87 FPU Data Register Stack Page Page Page CHAPTER 12 SSE, SSE2 AND SSE3 SYSTEM PROGRAMMING 12.1 PROVIDING OPERATING SYSTEM SUPPORT FOR SSE/SSE2/SSE3 EXTENSIONS 12.1.1 Adding Support to an Operating System for SSE/SSE2/SSE3 Extensions 12.1.2 Checking for SSE/SSE2/SSE3 Extension Support 12.1.3 Checking for Support for the FXSAVE and FXRSTOR Instructions 12.1.4 Initialization of the SSE/SSE2/SSE3 Extensions 12.1.6 Providing an Handler for the SIMD Floating-Point Exception (#XF) 12.2 EMULATION OF SSE/SSE2/SSE3 EXTENSIONS 12.3 SAVING AND RESTORING THE SSE/SSE2/SSE3 STATE 12.4 SAVING THE SSE/SSE2/SSE3 STATE ON TASK OR CONTEXT SWITCHES 12.5.1. Using the TS Flag to Control the Saving of the x87 FPU, MMX, SSE, SSE2 and SSE3 State Page Page Page Page CHAPTER 13 POWER AND THERMAL MANAGEMENT 13.1 ENHANCED INTEL SPEEDSTEP TECHNOLOGY 13.1.1 Software Interface For Initiating Performance State Transitions 13.2 P-STATE HARDWARE COORDINATION Page 13.3 MWAIT EXTENSIONS FOR ADVANCED POWER MANAGEMENT 13.4 THERMAL MONITORING AND PROTECTION 13.4.1 Catastrophic Shutdown Detector 13.4.2 Thermal Monitor Page Page 13.4.3 Software Controlled Clock Modulation Page 13.4.4 Detection of Thermal Monitor and Software Controlled Clock Modulation Facilities 13.4.5 On Die Digital Thermal Sensors Page Page Page Page Page CHAPTER 14 MACHINE-CHECK ARCHITECTURE 14.1 MACHINE-CHECK EXCEPTIONS AND ARCHITECTURE 14.2 COMPATIBILITY WITH PENTIUM PROCESSOR 14.3 MACHINE-CHECK MSRS 14.3.1 Machine-Check Global Control MSRs Page Page 14.3.2 Error-Reporting Register Banks Page Page Page MACHINE-CHECK ARCHITECTURE Table 14-2. Extended Machine Check State MSRs In Processors With Support For Intel EM64T Table 14-1. Extended Machine Check State MSRs in Processors Without Support for EM64T (Contd.) Page 14.3.3 Mapping of the Pentium Processor Machine-Check Errors to the Machine-Check Architecture 14.4 MACHINE-CHECK AVAILABILITY 14.5 MACHINE-CHECK INITIALIZATION Page 14.6. INTERPRETING THE MCA ERROR CODES 14.6.1 Simple Error Codes 14.6.2 Compound Error Codes Page Page 14.6.3 Machine-Check Error Codes Interpretation 14.7 GUIDELINES FOR WRITING MACHINE-CHECK SOFTWARE 14.7.1 Machine-Check Exception Handler 14.7.2 Enabling BINIT# Drive and BINIT# Observation 14.7.3 Pentium Processor Machine-Check Exception Handling 14.7.4 Logging Correctable Machine-Check Errors Page Page Page Page CHAPTER 15 8086 EMULATION 15.1 REAL-ADDRESS MODE Page 15.1.1 Address Translation in Real-Address Mode 15.1.2 Registers Supported in Real-Address Mode 15.1.3 Instructions Supported in Real-Address Mode + = Page 15.1.4 Interrupt and Exception Handling 15.2 VIRTUAL-8086 MODE Table 15-1. Real-Address Mode Exceptions and Interrupts 15.2.1 Enabling Virtual-8086 Mode 15.2.2 Structure of a Virtual-8086 Task 15.2.3 Paging of Virtual-8086 Tasks Figure 15-3. Entering and Leaving Virtual-8086 Mode 15.2.6 Leaving Virtual-8086 Mode 15.2.7 Sensitive Instructions 15.2.8 Virtual-8086 Mode I/O 15.3 INTERRUPT AND EXCEPTION HANDLING IN VIRTUAL-8086 MODE Page 15.3.1 Class 1Hardware Interrupt and Exception Handling in Virtual-8086 Mode Page Page Page Page 15.3.3 Class 3Software Interrupt Handling in Virtual-8086 Mode Table 15-2. Software Interrupt Handling Methods While in Virtual-8086 Mode Page Page Page 15.4 PROTECTED-MODE VIRTUAL INTERRUPTS Page Page CHAPTER 16 MIXING 16-BIT AND 32-BIT CODE 16.1 DEFINING 16-BIT AND 32-BIT PROGRAM MODULES 16.2 MIXING 16-BIT AND 32-BIT OPERATIONS WITHIN A CODE SEGMENT 16.3 SHARING DATA AMONG MIXED-SIZE CODE SEGMENTS Page 16.4.1 Code-Segment Pointer Size 16.4.2 Stack Management for Control Transfer Page 16.4.3 Interrupt Control Transfers 16.4.4 Parameter Translation 16.4.5 Writing Interface Procedures Page Page Page Page CHAPTER 17 IA-32 ARCHITECTURE COMPATIBILITY 17.1. IA-32 PROCESSOR FAMILIES AND CATEGORIES 17.2. RESERVED BITS 17.3. ENABLING NEW FUNCTIONS AND MODES 17.5. INTEL MMX TECHNOLOGY 17.6. STREAMING SIMD EXTENSIONS (SSE) 17.7. STREAMING SIMD EXTENSIONS 2 (SSE2) 17.8. STREAMING SIMD EXTENSIONS 3 (SSE3) 17.9. HYPER-THREADING TECHNOLOGY Page Page 17.15.1 Using EFLAGS Flags to Distinguish Between 32-Bit IA-32 17.16. STACK OPERATIONS 17.16.1 PUSH SP 17.16.2 EFLAGS Pushed on the Stack 17.17. X87 FPU 17.17.1 Control Register CR0 Flags 17.17.2 x87 FPU Status Word 17.17.3 x87 FPU Control Word 17.17.4 x87 FPU Tag Word 17.17.5 Data Types 17.17.6 Floating-Point Exceptions Page Page Page 17.17.7 Changes to Floating-Point Instructions Page Page 17.17.8 Transcendental Instructions 17.17.9 Obsolete Instructions 17.17.10WAIT/FWAIT Prefix Differences 17.17.11Operands Split Across Segments and/or Pages 17.17.12FPU Instruction Synchronization 17.18. SERIALIZING INSTRUCTIONS 17.19. FPU AND MATH COPROCESSOR INITIALIZATION 17.19.1 Intel387 and Intel287 Math Coprocessor Initialization 17.19.2 Intel486 SX Processor and Intel 487 SX Math Coprocessor Initialization 17.20. CONTROL REGISTERS Page 17.21. MEMORY MANAGEMENT FACILITIES 17.21.1 New Memory Management Control Flags 17.21.2 CD and NW Cache Control Flags 17.21.3 Descriptor Types and Contents 17.21.4 Changes in Segment Descriptor Loads 17.22. DEBUG FACILITIES 17.22.1 Differences in Debug Register DR6 17.22.2 Differences in Debug Register DR7 17.22.3 Debug Registers DR4 and DR5 17.23. RECOGNITION OF BREAKPOINTS 17.24. EXCEPTIONS AND/OR EXCEPTION CONDITIONS Page Page 17.25.3 IDT Limit 17.26. ADVANCED PROGRAMMABLE INTERRUPT CONTROLLER (APIC) 17.26.1 Software Visible Differences Between the Local APIC and the 82489DX Page 17.27.1 P6 Family and Pentium Processor TSS 17.27.2 TSS Selector Writes 17.27.3 Order of Reads/Writes to the TSS 17.27.4 Using A 16-Bit TSS with 32-Bit Constructs 17.27.5 Differences in I/O Map Base Addresses 17.28. CACHE MANAGEMENT 17.28.1 Self-Modifying Code with Cache Enabled 17.28.2 Disabling the L3 Cache 17.29. PAGING 17.29.1 Large Pages 17.29.2 PCD and PWT Flags 17.29.3 Enabling and Disabling Paging 17.30. STACK OPERATIONS 17.30.1 Selector Pushes and Pops 17.30.2 Error Code Pushes 17.30.3 Fault Handling Effects on the Stack 17.30.4 Interlevel RET/IRET From a 16-Bit Interrupt or Call Gate 17.31. MIXING 16- AND 32-BIT SEGMENTS 17.32. SEGMENT AND ADDRESS WRAPAROUND 17.33. STORE BUFFERS AND MEMORY ORDERING 17.34. BUS LOCKING 17.35. BUS HOLD 17.36. MODEL-SPECIFIC EXTENSIONS TO THE IA-32 17.36.1 Model-Specific Registers 17.36.2 RDMSR and WRMSR Instructions 17.36.3 Memory Type Range Registers 17.36.4 Machine-Check Exception and Architecture 17.36.5 Performance-Monitoring Counters 17.37. TWO WAYS TO RUN INTEL 286 PROCESSOR TASKS Page INTEL SALES OFFICES