Intel 64 and IA-32 Architectures Software Developers Manual Volume 2A, Instruction Set Reference, A-M

3-472 Vol. 2
INSTRUCTION SET REFERENCE, A-M
FI;
IF 32-bit gate
THEN
CS:EIP ← Gate(CS:EIP); (* Segment descriptor information also loaded *)
ELSE
IF 16-bit gate
THEN
CS:IP ← Gate(CS:IP);
(* Segment descriptor information also loaded *)
ELSE (* 64-bit gate *)
CS:RIP ← Gate(CS:RIP);
(* Segment descriptor information also loaded *)
FI;
FI;
IF 32-bit gate
THEN
Push(far pointer to old stack);
(* Old SS and ESP, 3 words padded to 4 *)
Push(EFLAGS);
Push(far pointer to return instruction);
(* Old CS and EIP, 3 words padded to 4 *)
Push(ErrorCode); (* If needed, 4 bytes *)
ELSE
IF 16-bit gate
THEN
Push(far pointer to old stack);
(* Old SS and SP, 2 words *)
Push(EFLAGS(15-0]);
Push(far pointer to return instruction);
(* Old CS and IP, 2 words *)
Push(ErrorCode); (* If needed, 2 bytes *)
ELSE (* 64-bit gate *)
Push(far pointer to old stack);
(* Old SS and SP, each an 8-byte push *)
Push(RFLAGS); (* 8-byte push *)
Push(far pointer to return instruction);
(* Old CS and RIP, each an 8-byte push *)
Push(ErrorCode); (* If needed, 8-bytes *)
FI;
FI;
CPL ← CodeSegmentDescriptor(DPL);
CS(RPL) ← CPL;
IF interrupt gate
THEN IF ← 0 (* Interrupt flag set to 0: disabled *); FI;