How to enable Code section (Read / Write) in x64

[chants]

However if you are dealing with Linux and 64 bit ELF files, the advice is similar but the headers and format different. Instead of VirtualProtect there is mprotect, etc. Based on responses, it's clear everyone here still uses Windows, myself included.

Also at ring0 there exists possibility of modifying page tables and changing the protection directly without using the OS API wrappers for this purpose.

The 32 bit calling conventions include fastcall, register, vectorcall and thiscall which do use registers. Sure cdecl and stdcall or Pascal conventions are common, but it's incorrect to say it doesn't use registers. Those conventions exist on a multitude of compilers. By 64 bit era there are so many registers added beyond there mere double bitwidth that for performance reasons there was no reason to keep stack only methods.