12.5: Standard Calling Convention

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To write assembly programs, a standard process for passing parameters, returning values, and allocating registers between functions is needed. If each function did these operations differently, things would quickly get very confusing and require programmers to attempt to remember for each function how to handle parameters and which registers were used. To address this, a standard process is defined and used which is typically referred to as a standard calling convention(For more information, refer to: http://en.Wikipedia.org/wiki/Calling_convention). There are actually a number of different standard calling conventions. The 64-bit C calling convention, called System V AMD64 ABI(For more information, refer to: https://en.Wikipedia.org/wiki/X86_ca...em_V_AMD64_ABI ; For complete details, refer to: https://software.intel.com/sites/def...inux64-abi.pdf), is described in the remainder of this document.

This calling convention is also used for C/C++ programs by default. This means that interfacing assembly language code and C/C++ code is easily accomplished since the same calling convention is used.

It must be noted that the standard calling convention presented here applies to Linux- based operating systems. The standard calling convention for Microsoft Windows is slightly different and not presented in this text.