← Home

ELR_EL3: Exception Link Register (EL3)

Purpose

When taking an exception to EL3, holds the address to return to.

Configuration

This register is present only when EL3 is implemented. Otherwise, direct accesses to ELR_EL3 are UNDEFINED.

Attributes

ELR_EL3 is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
Return address
Return address

Bits [63:0]

Return address.

An exception return from EL3 using AArch64 makes ELR_EL3 become UNKNOWN.

The reset behavior of this field is:

Accessing ELR_EL3

Accesses to this register use the following encodings in the System register encoding space:

MRS <Xt>, ELR_EL3

op0op1CRnCRmop2
0b110b1100b01000b00000b001

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then UNDEFINED; elsif PSTATE.EL == EL2 then UNDEFINED; elsif PSTATE.EL == EL3 then X[t, 64] = ELR_EL3;

MSR ELR_EL3, <Xt>

op0op1CRnCRmop2
0b110b1100b01000b00000b001

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then UNDEFINED; elsif PSTATE.EL == EL2 then UNDEFINED; elsif PSTATE.EL == EL3 then if IsFeatureImplemented(FEAT_GCS) && GetCurrentEXLOCKEN() && !Halted() && PSTATE.EXLOCK == '1' then EXLOCKException(); else ELR_EL3 = X[t, 64];