SP_EL2

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SP_EL2, Stack Pointer (EL2)

Purpose

Holds the stack pointer associated with EL2. The value of SPSel.SP determines the current stack pointer.

Configuration

This register is present only when FEAT_AA64 is implemented. Otherwise, direct accesses to SP_EL2 are UNDEFINED.

This register has no effect if EL2 is not enabled in the current Security state.

Attributes

Field descriptions

StackPointer, bits [63:0]

Accessing SP_EL2

This accessibility information only applies to accesses using the MRS or MSR instructions.

When the value of SPSel.SP is 1, this register is also accessible at EL2 as the current stack pointer.

Note

When the value of SPSel.SP is 0, SP_EL0 is used as the current stack pointer at all Exception levels.

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

MRS <Xt>, SP_EL2

op0	op1	CRn	CRm	op2
0b11	0b110	0b0100	0b0001	0b000

if !IsFeatureImplemented(FEAT_AA64) then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then Undefined(); elsif PSTATE.EL == EL2 then Undefined(); elsif PSTATE.EL == EL3 then X{64}(t) = SP_EL2(); end;

MSR SP_EL2, <Xt>

op0	op1	CRn	CRm	op2
0b11	0b110	0b0100	0b0001	0b000

63	62	61	60	59	58	57	56	55	54	53	52	51	50	49	48	47	46	45	44	43	42	41	40	39	38	37	36	35	34	33	32
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
StackPointer
StackPointer