Intel 64 and IA-32 Architectures Software Developers Manual Volume 1, Basic Architecture

6-6 Vol. 1
PROCEDURE CALLS, INTERRUPTS, AND EXCEPTIONS
When executing a near return, the processor performs these actions:
1. Pops the top-of-stack value (the return instruction pointer) into the EIP register.
2. If the RET instruction has an optional n argument, increments the stack pointer
by the number of bytes specified with the n operand to release parameters from
the stack.
3. Resumes execution of the calling procedure.
6.3.2 Far CALL and RET Operation
When executing a far call, the processor performs these actions (see Figure 6-2):
1. Pushes the current value of the CS register on the stack.
2. Pushes the current value of the EIP register on the stack.
3. Loads the segment selector of the segment that contains the called procedure in
the CS register.
4. Loads the offset of the called procedure in the EIP register.
5. Begins execution of the called procedure.
When executing a far return, the processor does the following:
1. Pops the top-of-stack value (the return instruction pointer) into the EIP register.
2. Pops the top-of-stack value (the segment selector for the code segment being
returned to) into the CS register.
3. If the RET instruction has an optional n argument, increments the stack pointer
by the number of bytes specified with the n operand to release parameters from
the stack.
4. Resumes execution of the calling procedure.