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.
| 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| 1 | 1 | 0 | 1 | 0 | 1 | 1 | 0 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 |
| opc | op2 | A | M | Rn | op4 | ||||||||||||||||||||||||||
boolean pac = FALSE; boolean use_key_a = TRUE;
if PSTATE.EL == EL0 then UNDEFINED; AArch64.CheckForERetTrap(pac, use_key_a); bits(64) target = ELR_ELx[]; AArch64.ExceptionReturn(target, SPSR_ELx[]);
Internal version only: aarchmrs v2024-03_relA, pseudocode v2024-03_rel, sve v2024-03_rel ; Build timestamp: 2024-03-26T09:45
Copyright © 2010-2024 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.