Writing an X86–64 Assembly Language Program

Part VII: Quick Reference

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This article is more of a reference guide for those learning x86–64 Assembly Language. I hope you find the information and links at the bottom helpful.

This reference guide is part seven of a series

• Part one: Getting Started Writing Assembly Language
• Part two: Finding an Efficient Development Cycle for writing Assembly Language
• Part three: Writing an X86–64 Assembly Language Program: Printing Command Line Arguments
• Part four: Writing an X86–64 Assembly Language Program: Sending Function Arguments and Receiving a Return Value
• Part five: Writing an X86–64 Assembly Language Program: Conditionals, Jumping, and Looping
• Part six: Writing an X86–64 Assembly Language Program: How to Determine String Length

Registers

General-purpose registers — there are 16 general-purpose registers — rax, rbx, rcx, rdx, rbp, rsp, rsi, rdi, r8, r9, r10, r11, r12, r13, r14, r15

• data- section is used for declaring initialized data or constants
• bss- section is used for declaring non initialized variables
• text- section is used for code
• rdi- first argument
• rsi- second argument
• rdx- third argument
• rcx- fourth argument
• r8- fifth argument
• r9- sixth

The first six integer or pointer arguments are passed in registers rdi, rsi, rdx, rcx, r8, r9. r10 is used as a static chain pointer in the case of nested functions.

rax is used as the return value from a function.

The registers rbx, rbp, and r12– r15 are preserved registers.

All other registers must be saved by the caller if it wishes to preserve its values.

OPERATIONS

• ADD- integer add
• SUB- subtract
• MUL- unsigned multiply
• IMUL- signed multiply