BRBFCR

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BRBFCR_EL1, Branch Record Buffer Function Control Register

Purpose

Configuration

This register is present only when FEAT_BRBE is implemented. Otherwise, direct accesses to BRBFCR_EL1 are UNDEFINED.

Attributes

Field descriptions

Bits [63:30]

BANK, bits [29:28]

Bits [27:23]

CONDDIR, bit [22]

DIRCALL, bit [21]

INDCALL, bit [20]

RTN, bit [19]

INDIRECT, bit [18]

DIRECT, bit [17]

EnI, bit [16]

Bits [15:8]

PAUSED, bit [7]

Bits [6:0]

BANK	Meaning
0b00	Select branch records 0 to 31.
0b01	Select branch records 32 to 63.

CONDDIR	Meaning
0b0	Do not match on conditional direct branch instructions.
0b1	Match on conditional direct branch instructions.

DIRCALL	Meaning
0b0	Do not match on direct branch with link instructions.
0b1	Match on direct branch with link instructions.

INDCALL	Meaning
0b0	Do not match on indirect branch with link instructions.
0b1	Match on indirect branch with link instructions.

RTN	Meaning
0b0	Do not match on function return instructions.
0b1	Match on function return instructions.

INDIRECT	Meaning
0b0	Do not match on indirect branch instructions.
0b1	Match on indirect branch instructions.

DIRECT	Meaning
0b0	Do not match on unconditional direct branch instructions.
0b1	Match on unconditional direct branch instructions.

EnI	Meaning
0b0	Include records for matches, and exclude records for non-matches.
0b1	Exclude records for matches, and include records for non-matches.

PAUSED	Meaning
0b0	Branch recording is not Paused.
0b1	Branch recording is Paused.

Accessing BRBFCR_EL1

Accesses to this register use the following encodings in the System register encoding space:

MRS <Xt>, BRBFCR_EL1

op0	op1	CRn	CRm	op2
0b10	0b001	0b1001	0b0000	0b001

if !IsFeatureImplemented(FEAT_BRBE) 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') && HDFGRTR_EL2().nBRBCTL == '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); end; elsif HaveEL(EL3) && MDCR_EL3().SBRBE IN {'x0'} && SCR_EL3().NS == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else X{64}(t) = BRBFCR_EL1(); end; 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); end; elsif HaveEL(EL3) && MDCR_EL3().SBRBE IN {'x0'} && SCR_EL3().NS == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else X{64}(t) = BRBFCR_EL1(); end; elsif PSTATE.EL == EL3 then X{64}(t) = BRBFCR_EL1(); end;

MSR BRBFCR_EL1, <Xt>

op0	op1	CRn	CRm	op2
0b10	0b001	0b1001	0b0000	0b001

if !IsFeatureImplemented(FEAT_BRBE) 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') && HDFGWTR_EL2().nBRBCTL == '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); end; elsif HaveEL(EL3) && MDCR_EL3().SBRBE IN {'x0'} && SCR_EL3().NS == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else BRBFCR_EL1() = X{64}(t); end; 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); end; elsif HaveEL(EL3) && MDCR_EL3().SBRBE IN {'x0'} && SCR_EL3().NS == '1' then if EL3SDDUndef() then Undefined(); else AArch64_SystemAccessTrap(EL3, 0x18); end; else BRBFCR_EL1() = X{64}(t); end; elsif PSTATE.EL == EL3 then BRBFCR_EL1() = X{64}(t); end;

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
RES0
RES0		BANK		RES0					CONDDIR	DIRCALL	INDCALL	RTN	INDIRECT	DIRECT	EnI	RES0								PAUSED	RES0