The SP_EL1 characteristics are:
Holds the capability stack pointer associated with EL1 and Executive. When executing at EL1, the values of SPSel.SP and the Executive bit of PCC determine the current capability stack pointer:
SPSel.SP | Executive bit of PCC | Current stack pointer |
---|---|---|
0bx | 0b0 | RSP_EL0 |
0b0 | 0b1 | SP_EL0 |
0b1 | 0b1 | SP_EL1 |
RW fields in this register reset to architecturally UNKNOWN values.
SP_EL1 is a 129-bit register.
The SP_EL1 bit assignments are:
Stack pointer
This field resets to an architecturally UNKNOWN value.
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 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 EL1 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 | 0b100 | 0b0100 | 0b0001 | 0b000 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then UNDEFINED; elsif PSTATE.EL == EL2 then if IsFeatureImplemented("Morello") && IsInRestricted() && !Halted() then UNDEFINED; else return SP_EL1<63:0>; elsif PSTATE.EL == EL3 then if IsFeatureImplemented("Morello") && IsInRestricted() && !Halted() then UNDEFINED; else return SP_EL1<63:0>;
op0 | op1 | CRn | CRm | op2 |
---|---|---|---|---|
0b11 | 0b100 | 0b0100 | 0b0001 | 0b000 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then UNDEFINED; elsif PSTATE.EL == EL2 then if IsFeatureImplemented("Morello") && IsInRestricted() && !Halted() then UNDEFINED; else SP_EL1 = ZeroExtend(X[t]); elsif PSTATE.EL == EL3 then if IsFeatureImplemented("Morello") && IsInRestricted() && !Halted() then UNDEFINED; else SP_EL1 = ZeroExtend(X[t]);
op0 | op1 | CRn | CRm | op2 |
---|---|---|---|---|
0b11 | 0b100 | 0b0100 | 0b0001 | 0b000 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then UNDEFINED; elsif PSTATE.EL == EL2 then if IsFeatureImplemented("Morello") && IsInRestricted() && !Halted() then UNDEFINED; elsif HCR_EL2.E2H == '0' && CPTR_EL2.TC == '1' then AArch64.SystemAccessTrap(EL2, 0x29); elsif HCR_EL2.E2H == '1' && CPTR_EL2.CEN == 'x0' then AArch64.SystemAccessTrap(EL2, 0x29); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && CPTR_EL3.EC == '0' then AArch64.SystemAccessTrap(EL3, 0x29); else return SP_EL1; elsif PSTATE.EL == EL3 then if IsFeatureImplemented("Morello") && IsInRestricted() && !Halted() then UNDEFINED; elsif CPTR_EL3.EC == '0' then AArch64.SystemAccessTrap(EL3, 0x29); else return SP_EL1;
op0 | op1 | CRn | CRm | op2 |
---|---|---|---|---|
0b11 | 0b100 | 0b0100 | 0b0001 | 0b000 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then UNDEFINED; elsif PSTATE.EL == EL2 then if IsFeatureImplemented("Morello") && IsInRestricted() && !Halted() then UNDEFINED; elsif HCR_EL2.E2H == '0' && CPTR_EL2.TC == '1' then AArch64.SystemAccessTrap(EL2, 0x29); elsif HCR_EL2.E2H == '1' && CPTR_EL2.CEN == 'x0' then AArch64.SystemAccessTrap(EL2, 0x29); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && CPTR_EL3.EC == '0' then AArch64.SystemAccessTrap(EL3, 0x29); else SP_EL1 = C[t]; elsif PSTATE.EL == EL3 then if IsFeatureImplemented("Morello") && IsInRestricted() && !Halted() then UNDEFINED; elsif CPTR_EL3.EC == '0' then AArch64.SystemAccessTrap(EL3, 0x29); else SP_EL1 = C[t];
12/01/2022 09:56; 05a4944b4b04e7ab50def8c126b479d22136f35b
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