README.md

Hello x64

"Hello World" implemented in x86-64 machine code for Linux.

Goal: Explore x86-64 (instruction encoding) & System V (executables).

Build

make hello

Resources

Tools

• NASM manual
• GNU Make manual

x86 & AMD64

• Intel 64 and IA-32 manuals
• AMD64 Architecture Programmer's Manual Volume 3
• x86 and AMD64 Instruction Reference

System V

• System V Specification
• ELF
• elf.h

Linux

• Linux System calls
• Linux System call Table

Relocation

• System V ABI Specification
• Linker and Libraries Guide: Object File Format
• R_X86_64_32S and R_X86_64_64

Virtual Address 0x00400000

• Why is 0x00400000 the default base address for an executable?
• Why is address 0x400000 chosen as a start of text segment in x86_64 ABI?