The SP_EL1 characteristics are:
Holds the stack pointer associated with EL1. When executing at EL1, the value of SPSel.SP determines the current stack pointer:
SPSel.SP | current stack pointer |
---|---|
0 | SP_EL0 |
1 | SP_EL1 |
This register is part of the Special-purpose registers functional group.
There are no configuration notes.
SP_EL1 is a 64-bit register.
The SP_EL1 bit assignments are:
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 |
Stack pointer | |||||||||||||||||||||||||||||||
Stack pointer | |||||||||||||||||||||||||||||||
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 |
Stack pointer.
This register can be read using MRS with the following syntax:
MRS <Xt>, <systemreg>
This register can be written using MSR (register) with the following syntax:
MSR <systemreg>, <Xt>
This syntax uses the following encoding in the System instruction encoding space:
<systemreg> | op0 | op1 | CRn | CRm | op2 |
---|---|---|---|---|---|
SP_EL1 | 11 | 100 | 0100 | 0001 | 000 |
The register is accessible as follows:
Control | Accessibility | |||||
---|---|---|---|---|---|---|
E2H | TGE | NS | EL0 | EL1 | EL2 | EL3 |
x | x | 0 | - | - | n/a | RW |
x | 0 | 1 | - | - | RW | RW |
x | 1 | 1 | - | n/a | RW | RW |
This table applies to all instructions that can access this register.
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 EL1 as the current stack pointer.
18/04/2017 17:00
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