This manual documents NASM, the Netwide Assembler: an assembler targetting the Intel x86 series of processors, with portable source.
Chapter 1: Introduction
Section 1.1: What Is NASM?
Section 1.1.1: Why Yet Another Assembler?
Section 1.1.2: Licence Conditions
Section 1.2: Contact Information
Section 1.3: Installation
Section 1.3.1: Installing NASM under MS-DOS or Windows
Section 1.3.2: Installing NASM under Unix
Chapter 2: Running NASM
Section 2.1: NASM Command-Line Syntax
Section 2.1.1: The
Section 2.1.2: The
Section 2.1.3: The
Section 2.1.4: The
Section 2.1.5: The
Section 2.1.6: The
Section 2.1.7: The
Section 2.1.8: The
Section 2.1.9: The
Section 2.1.10: The
Section 2.1.11: The
Section 2.1.12: The
Section 2.1.13: The
Section 2.1.14: The
Section 2.2: Quick Start for MASM Users
Section 2.2.1: NASM Is Case-Sensitive
Section 2.2.2: NASM Requires Square Brackets For Memory References
Section 2.2.3: NASM Doesn't Store Variable Types
Section 2.2.4: NASM Doesn't
Section 2.2.5: NASM Doesn't Support Memory Models
Section 2.2.6: Floating-Point Differences
Section 2.2.7: Other Differences
Chapter 3: The NASM Language
Section 3.1: Layout of a NASM Source Line
Section 3.2: Pseudo-Instructions
Section 3.2.1:
Section 3.2.2:
Section 3.2.3:
Section 3.2.4:
Section 3.2.5:
Section 3.3: Effective Addresses
Section 3.4: Constants
Section 3.4.1: Numeric Constants
Section 3.4.2: Character Constants
Section 3.4.3: String Constants
Section 3.4.4: Floating-Point Constants
Section 3.5: Expressions
Section 3.5.1:
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Section 3.5.7: Unary Operators:
Section 3.6:
Section 3.7: Critical Expressions
Section 3.8: Local Labels
Chapter 4: The NASM Preprocessor
Section 4.1: Single-Line Macros
Section 4.1.1: The Normal Way:
Section 4.1.2: Undefining macros:
Section 4.1.3: Preprocessor Variables:
Section 4.2: String Handling in Macros:
Section 4.2.1: String Length:
Section 4.2.2: Sub-strings:
Section 4.3: Multi-Line Macros:
Section 4.3.1: Overloading Multi-Line Macros
Section 4.3.2: Macro-Local Labels
Section 4.3.3: Greedy Macro Parameters
Section 4.3.4: Default Macro Parameters
Section 4.3.5:
Section 4.3.6:
Section 4.3.7: Concatenating Macro Parameters
Section 4.3.8: Condition Codes as Macro Parameters
Section 4.3.9: Disabling Listing Expansion
Section 4.4: Conditional Assembly
Section 4.4.1:
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Section 4.4.6:
Section 4.5: Preprocessor Loops:
Section 4.6: Including Other Files
Section 4.7: The Context Stack
Section 4.7.1:
Section 4.7.2: Context-Local Labels
Section 4.7.3: Context-Local Single-Line Macros
Section 4.7.4:
Section 4.7.5: Example Use of the Context Stack: Block IFs
Section 4.8: Standard Macros
Section 4.8.1:
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Section 4.9: TASM Compatible Preprocessor Directives
Section 4.9.1:
Section 4.9.2:
Section 4.9.3:
Chapter 5: Assembler Directives
Section 5.1:
Section 5.2:
Section 5.2.1: The
Section 5.3:
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Section 5.5:
Section 5.6:
Chapter 6: Output Formats
Section 6.1:
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Section 6.5:
Section 6.5.1:
Section 6.5.2: Position-Independent Code:
Section 6.5.3:
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Section 6.6:
Section 6.7:
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Section 6.9:
Section 6.9.1: Requiring a Library: The
Section 6.9.2: Specifying a Module Name: The
Section 6.9.3:
Section 6.10:
Chapter 7: Writing 16-bit Code (DOS, Windows 3/3.1)
Section 7.1: Producing
Section 7.1.1: Using the
Section 7.1.2: Using the
Section 7.2: Producing
Section 7.2.1: Using the
Section 7.2.2: Using the
Section 7.3: Producing
Section 7.4: Interfacing to 16-bit C Programs
Section 7.4.1: External Symbol Names
Section 7.4.2: Memory Models
Section 7.4.3: Function Definitions and Function Calls
Section 7.4.4: Accessing Data Items
Section 7.4.5:
Section 7.5: Interfacing to Borland Pascal Programs
Section 7.5.1: The Pascal Calling Convention
Section 7.5.2: Borland Pascal Segment Name Restrictions
Section 7.5.3: Using
Chapter 8: Writing 32-bit Code (Unix, Win32, DJGPP)
Section 8.1: Interfacing to 32-bit C Programs
Section 8.1.1: External Symbol Names
Section 8.1.2: Function Definitions and Function Calls
Section 8.1.3: Accessing Data Items
Section 8.1.4:
Section 8.2: Writing NetBSD/FreeBSD/OpenBSD and Linux/ELF Shared Libraries
Section 8.2.1: Obtaining the Address of the GOT
Section 8.2.2: Finding Your Local Data Items
Section 8.2.3: Finding External and Common Data Items
Section 8.2.4: Exporting Symbols to the Library User
Section 8.2.5: Calling Procedures Outside the Library
Section 8.2.6: Generating the Library File
Chapter 9: Mixing 16 and 32 Bit Code
Section 9.1: Mixed-Size Jumps
Section 9.2: Addressing Between Different-Size Segments
Section 9.3: Other Mixed-Size Instructions
Chapter 10: Troubleshooting
Section 10.1: Common Problems
Section 10.1.1: NASM Generates Inefficient Code
Section 10.1.2: My Jumps are Out of Range
Section 10.1.3:
Section 10.1.4:
Section 10.2: Bugs
Appendix A: Intel x86 Instruction Reference
Section A.1: Key to Operand Specifications
Section A.2: Key to Opcode Descriptions
Section A.2.1: Register Values
Section A.2.2: Condition Codes
Section A.2.3: Effective Address Encoding: ModR/M and SIB
Section A.3: Key to Instruction Flags
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