Intel 253666-024US User Manual
Page 526
3-480 Vol. 2A
INT n/INTO/INT 3—Call to Interrupt Procedure
INSTRUCTION SET REFERENCE, A-M
TempSS ← SS;
TempESP ← ESP;
SS:ESP ← TSS(SS0:ESP0); (* Change to level 0 stack segment *)
(* Following pushes are 16 bits for 16-bit gate and 32 bits for 32-bit gates;
Segment selector pushes in 32-bit mode are padded to two words *)
Push(GS);
Push(FS);
Push(DS);
Push(ES);
Push(TempSS);
Push(TempESP);
Push(TempEFlags);
Push(CS);
Push(EIP);
GS ← 0; (* Segment registers NULLified, invalid in protected mode *)
FS ← 0;
DS ← 0;
ES ← 0;
CS ← Gate(CS);
IF OperandSize
=
32
THEN
EIP ← Gate(instruction pointer);
ELSE (* OperandSize is 16 *)
EIP ← Gate(instruction pointer) AND 0000FFFFH;
FI;
(* Start execution of new routine in Protected Mode *)
END;
INTRA-PRIVILEGE-LEVEL-INTERRUPT:
(* PE
=
1, DPL
=
CPL or conforming segment *)
IF 32-bit gate and IA32_EFER.LMA = 0
THEN
IF current stack does not have room for 16 bytes (error code pushed)
or 12 bytes (no error code pushed)
THEN #SS(0); FI;
ELSE IF 16-bit gate
IF current stack does not have room for 8 bytes (error code pushed)
or 6 bytes (no error code pushed)
THEN #SS(0); FI;
ELSE (* 64-bit gate*)
IF StackAddress is non-canonical
THEN #SS(0);
FI;
FI;