The SP_EL2 characteristics are:
Holds the stack pointer associated with EL2. When executing at EL2, the value of SPSel. SP determines the current stack pointer:
SPSel.SP | Current stack pointer |
---|---|
0b0 | SP_EL0 |
0b1 | SP_EL2 |
This register has no effect if EL2 is not enabled in the current Security state.
SP_EL2 is a 64-bit register.
The SP_EL2 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 |
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 | |||||||||||||||||||||||||||||||
Stack pointer |
Stack pointer.
On a Warm reset, this field resets to an architecturally UNKNOWN value.
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.
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:
op0 | op1 | CRn | CRm | op2 |
---|---|---|---|---|
0b11 | 0b110 | 0b0100 | 0b0001 | 0b000 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then UNDEFINED; elsif PSTATE.EL == EL2 then UNDEFINED; elsif PSTATE.EL == EL3 then return SP_EL2;
op0 | op1 | CRn | CRm | op2 |
---|---|---|---|---|
0b11 | 0b110 | 0b0100 | 0b0001 | 0b000 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then UNDEFINED; elsif PSTATE.EL == EL2 then UNDEFINED; elsif PSTATE.EL == EL3 then SP_EL2 = X[t];
30/03/2021 20:51; e3551d56dc294a4d55296a6c10544191ada08a8e
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