C to assembly call convention 32bit vs 64bit

Question

I have been following the excellent book Programming Ground Up, wanting to learn assembly. Although not in the book at this point, I wanted to call my assembly function from C.

Answer 1

64-bit C calling convention is: %rdi, %rsi, %rdx, %rcx, %r8 and %r9

See full description here: "System V Application Binary Interface: AMD64 Architecture Processor Supplement" http://www.x86-64.org/documentation/abi.pdf

3.2 Function Calling Sequence

When I learned the same topic, I made small C programs with required functions, compiled them in 64 bit compiler and read the Assembly code produced by C compiler. C/C++ compiler can be used like kind of Assembly reference.