Understanding the basics of the Application Binary Interface (ABI)
In order to gain access to the parameters of a function, you have to first understand at least the basics of how the compiler arranges for the parameters to be passed. At the level of the assembly (assuming the programming language is C), you'll realize that it's really the compiler that generates the required assembly that actually implements the function call, parameter passing, local variable instantiation, and return!
But how does the compiler manage to do this? Compiler authors need to understand how the machine works... Obviously, all of this is very arch-specific; the precise specification as to how exactly function calling conventions, return value placement, stack and register usage, and so on, is provided by the microprocessor documentation called the ABI document.
Briefly, the ABI conveys the underlying details at the level of the machine concerning the following:
- CPU register usage...
