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SP_EL3

SP_EL3, Stack Pointer (EL3)

The SP_EL3 characteristics are:

Purpose

Holds the stack pointer associated with EL3. The value of SPSel.SP determines the current stack pointer.

Configuration

This register is present only when EL3 is implemented and FEAT_AA64 is implemented. Otherwise, direct accesses to SP_EL3 are UNDEFINED.

Attributes

SP_EL3 is a 64-bit register.

Field descriptions

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

StackPointer, bits [63:0]

Stack pointer.

The reset behavior of this field is:

On a Warm reset, this field resets to an architecturally UNKNOWN value.

Accessing SP_EL3

This register is not accessible using MRS and MSR instructions.

When the value of SPSel.SP is 1, this register is accessible at EL3 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.

2026-03-26 20:27:25, 2026-03_rel