ABI and Calling Conventions

Purpose

Document application binary interface (ABI) rules: register roles, stack alignment, argument passing, return values, and variadic conventions across System V AMD64, ARM AAPCS, and RISC-V — essential for assembly, FFI, and debugging.

When to Use

• Writing assembly thunks or inline asm clobbers
• Debugging corrupted stack in mixed C/asm
• FFI between Rust/C/Zig (skills/rust/rust-ffi, skills/zig/zig-cinterop)
• Reading disassembly from skills/debuggers/gdb

Workflow

1. System V AMD64 (Linux/macOS)