eret

Exception Return

ERET

Returns from an exception.

Pseudocode Operation

PC ← ELR_ELx
CPSR ← SPSR_ELx
Branch(PC)

Encoding

Binary Layout

1101011

31:25

0100

24:21

11111

20:16

0000

15:12

0

11

0

10

11111

9:5

00000

4:0

 

Format System

Opcode 0xD69F03E0

Extension Base

Operands

Related

Other forms of eret

• eret Exception Return (A32)
• eret Exception Return (Thumb)

More in Base

Reference

View in Arm A64 ISA Reference ↗ Arm A64 ISA

Instruction Forms

Encoding	Instruction		ISA		Bit pattern
0xD69F03E0	ERET		A64		1101011 | 0100 | 11111 | 0000 | 0 | 0 | 11111 | 00000

Description

Exception Return using the ELR and SPSR for the current Exception level. When executed, the PE restores PSTATE from the SPSR, and branches to the address held in the ELR. The PE checks the SPSR for the current Exception level for an illegal return event. See Illegal return events from AArch64 state. ERET is UNDEFINED at EL0.

Operation

if PSTATE.EL == EL0 then UNDEFINED;
AArch64.CheckForERetTrap(FALSE, TRUE);
bits(64) target = ELR_ELx[];

AArch64.ExceptionReturn(target, SPSR_ELx[]);