ENDBR64 - Terminate an Indirect Branch in 64-bit Mode

Opcode/ Instruction

Op / En

64/32 bit Mode Support

CPUID Feature Flag

Description

F3 0F 1E FA ENDBR64

ZO

V/V

CET_IBT

Terminate indirect branch in 64-bit mode.

Instruction Operand Encoding

Op/En

Tuple Type

Operand 1

Operand 2

Operand 3

Operand 4

ZO

N/A

N/A

N/A

N/A

N/A

Description

Terminate an indirect branch in 64 bit mode.

Operation 

IF EndbranchEnabled(CPL) & IA32_EFER.LMA = 1 & CS.L = 1
   IF CPL = 3
       THEN
            IA32_U_CET.TRACKER = IDLE
            IA32_U_CET.SUPPRESS = 0
       ELSE
            IA32_S_CET.TRACKER = IDLE
            IA32_S_CET.SUPPRESS = 0
   FI;
FI;

Flags Affected

None.

Exceptions

None.