x64 Assembly and C++ Tutorial 27: Calling C++ from ASM

In this, the 27th, tutorial, we will looking at the “C“ calling convention from the Caller’s point of view. This is not Assembly. It’s the meaning of ’extern “C“’ that we’ve been placing at the start of our procedures. Parameters used to be pushed onto the stack from right to left but nowadays the first four are passed by the registers RCX, RDX, R8 and R9 respectively. Stack space is still preserved for these parameters in the form of “Shadow Space“. Shadow space is the space that the first four parameters