NASM — The Netwide Assembler version 0.98.38 -~~..~:#;L .-:#;L,.- .~:#:;.T -~~.~:;. .~:;. E8+U *T +U' *T# .97 *L E8+' *;T' *;, D97 `*L .97 '*L "T;E+:, D9 *L *L H7 I# T7 I# "*:. H7 I# I# U: :8 *#+ , :8 T, 79 U: :8 :8 ,#B. .IE, "T;E* .IE, J *+;#:T*" ,#B. .IE, .IE, © 2003 The NASM Development Team All rights reserved. This document is redistributable under the licence given in the file "COPYING" distributed in the NASM archive. Contents Chapter 1: Introduction. .20 1.1 What Is NASM? . .20 1.1.1 Why Yet Another Assembler? . .20 1.1.2 Licence Conditions. .20 1.2 Contact Information . .20 1.3 Installation . .21 1.3.1 Installing NASM under MS−DOS or Windows . .21 1.3.2 Installing NASM under Unix . .21 Chapter 2: Running NASM . .23 2.1 NASM Command−Line Syntax . .23 2.1.1 The −o Option: Specifying the Output File Name . .23 2.1.2 The −f Option: Specifying the Output File Format . .24 2.1.3 The −l Option: Generating a Listing File. .24 2.1.4 The −M Option: Generate Makefile Dependencies. .24 2.1.5 The −F Option: Selecting a Debug Information Format . .24 2.1.6 The −g Option: Enabling Debug Information. .24 2.1.7 The −X Option: Selecting an Error Reporting Format . .25 2.1.8 The −E Option: Send Errors to a File . .25 2.1.9 The −s Option: Send Errors to stdout . .25 2.1.10 The −i Option: Include File Search Directories. .25 2.1.11 The −p Option: Pre−Include a File. .26 2.1.12 The −d Option: Pre−Define a Macro . .26 2.1.13 The −u Option: Undefine a Macro . .26 2.1.14 The −e Option: Preprocess Only. .26 2.1.15 The −a Option: Don’t Preprocess At All . .27 2.1.16 The −On Option: Specifying Multipass Optimization. .27 2.1.17 The −t option: Enable TASM Compatibility Mode . .27 2.1.18 The −w Option: Enable or Disable Assembly Warnings . .28 2.1.19 The −v Option: Display Version Info . .28 2.1.20 The −y Option: Display Available Debug Info Formats . .28 3 2.1.21 The −−prefix and −−postfix Options. .28 2.1.22 The NASMENV Environment Variable . .28 2.2 Quick Start for MASM Users. .29 2.2.1 NASM Is Case−Sensitive . .29 2.2.2 NASM Requires Square Brackets For Memory References . .29 2.2.3 NASM Doesn’t Store Variable Types . .30 2.2.4 NASM Doesn’t ASSUME . .30 2.2.5 NASM Doesn’t Support Memory Models . .30 2.2.6 Floating−Point Differences . .30 2.2.7 Other Differences. .30 Chapter 3: The NASM Language . .31 3.1 Layout of a NASM Source Line . .31 3.2 Pseudo−Instructions . .32 3.2.1 DB and friends: Declaring Initialised Data . .32 3.2.2 RESB and friends: Declaring Uninitialised Data . .32 3.2.3 INCBIN: Including External Binary Files . .32 3.2.4 EQU: Defining Constants. .33 3.2.5 TIMES: Repeating Instructions or Data . .33 3.3 Effective Addresses . .33 3.4 Constants. .34 3.4.1 Numeric Constants . .34 3.4.2 Character Constants . .35 3.4.3 String Constants . .35 3.4.4 Floating−Point Constants . .35 3.5 Expressions . .36 3.5.1 |: Bitwise OR Operator . .36 3.5.2 ^: Bitwise XOR Operator . .36 3.5.3 &: Bitwise AND Operator . .36 3.5.4 << and >>: Bit Shift Operators . .36 3.5.5 + and −: Addition and Subtraction Operators . .36 3.5.6 *, /, //, % and %%: Multiplication and Division . .36 3.5.7 Unary Operators: +, −, ~ and SEG . .36 3.6 SEG and WRT . .37 3.7 STRICT: Inhibiting Optimization . .37 3.8 Critical Expressions . .38 4 3.9 Local Labels . .39 Chapter 4: The NASM Preprocessor . .41 4.1 Single−Line Macros. .41 4.1.1 The Normal Way: %define . .41 4.1.2 Enhancing %define: %xdefine . .42 4.1.3 Concatenating Single Line Macro Tokens: %+ . .43 4.1.4 Undefining macros: %undef . .43 4.1.5 Preprocessor Variables: %assign . .43 4.2 String Handling in Macros: %strlen and %substr . .44 4.2.1 String Length: %strlen . .44 4.2.2 Sub−strings: %substr . .44 4.3 Multi−Line Macros: %macro . .44 4.3.1 Overloading Multi−Line Macros . .45 4.3.2 Macro−Local Labels . .46 4.3.3 Greedy Macro Parameters . .46 4.3.4 Default Macro Parameters . .47 4.3.5 %0: Macro Parameter Counter . .48 4.3.6 %rotate: Rotating Macro Parameters . .48 4.3.7 Concatenating Macro Parameters . .49 4.3.8 Condition Codes as Macro Parameters . .50 4.3.9 Disabling Listing Expansion. .50 4.4 Conditional Assembly. .50 4.4.1 %ifdef: Testing Single−Line Macro Existence . .51 4.4.2 ifmacro: Testing Multi−Line Macro Existence . .51 4.4.3 %ifctx: Testing the Context Stack . .51 4.4.4 %if: Testing Arbitrary Numeric Expressions . .52 4.4.5 %ifidn and %ifidni: Testing Exact Text Identity . .52 4.4.6 %ifid, %ifnum, %ifstr: Testing Token Types. .52 4.4.7 %error: Reporting User−Defined Errors . .53 4.5 Preprocessor Loops: %rep . .54 4.6 Including Other Files . .54 4.7 The Context Stack . .55 4.7.1 %push and %pop: Creating and Removing Contexts . .55 4.7.2 Context−Local Labels . ..