x86-64 Assembly Guide (AMD64 / Intel 64, Intel (NASM) syntax)
Contents: Registers | Memory and Addressing | Instructions | Calling Convention (System V AMD64) This page is a 64-bit (x86-64) adaptation of the classic 32-bit x86 Assembly Guide, rewritten for NASM in Intel syntax. We assume x86-64 on UNIX-like systems (Linux/BSD/macOS) and focus on the instruction subset used in typical systems/CS courses. NASM + Intel syntax basics Compared to AT&T syntax: Operand order is destination, source. Registers are written without a % prefix (e....