Branch Record Injection into the Branch Record Buffer
Injects the Branch Record held in BRBINFINJ_EL1, BRBSRCINJ_EL1, and BRBTGTINJ_EL1 into the Branch Record Buffer.
This instruction is present only when FEAT_BRBE is implemented and FEAT_AA64 is implemented. Otherwise, direct accesses to BRB INJ are UNDEFINED.
BRB INJ is a 64-bit System instruction.
This instruction has no applicable fields.
The value in the register specified by <Xt> is ignored.
Rt should be encoded as 0b11111. If the Rt field is not set to 0b11111, it is CONSTRAINED UNPREDICTABLE whether:
The instruction is UNDEFINED.
The instruction behaves as if the Rt field is set to 0b11111.
Accesses to this instruction use the following encodings in the System instruction encoding space:
BRB INJ
(op0 = 0b01, op1 = 0b001, CRn = 0b0111, CRm = 0b0010, op2 = 0b101)
if !(IsFeatureImplemented(FEAT_BRBE) && IsFeatureImplemented(FEAT_AA64)) then UNDEFINED; elsif PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.SBRBE != '11' && SCR_EL3.NS == '0' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.SBRBE IN {'x0'} && SCR_EL3.NS == '1' then UNDEFINED; elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HFGITR_EL2.nBRBINJ == '0' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && MDCR_EL3.SBRBE != '11' && SCR_EL3.NS == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif HaveEL(EL3) && MDCR_EL3.SBRBE IN {'x0'} && SCR_EL3.NS == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else BRB_INJ(); elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.SBRBE != '11' && SCR_EL3.NS == '0' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && MDCR_EL3.SBRBE IN {'x0'} && SCR_EL3.NS == '1' then UNDEFINED; elsif HaveEL(EL3) && MDCR_EL3.SBRBE != '11' && SCR_EL3.NS == '0' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif HaveEL(EL3) && MDCR_EL3.SBRBE IN {'x0'} && SCR_EL3.NS == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else BRB_INJ(); elsif PSTATE.EL == EL3 then BRB_INJ();
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