brb

Branch Record Buffer Injection

BRB <op>

Injects an entry into the Branch Record Buffer (Debug).

Details

Injects an entry into the Branch Record Buffer (BRB) for debugging purposes. This is a privileged system instruction that requires EL1 or higher execution level and is only available when FEAT_BRBE is implemented. The instruction does not affect any condition flags.

Pseudocode Operation

if PSTATE.EL == EL0 then
  UNDEFINED
else
  case op of
    when '0' BRBIall()
    when '1' BRBInj()

Example

BRB op

Encoding

Binary Layout

1101010100

001

0111

0010

op2

Format System

Opcode 0xD5097200

Extension FEAT_BRBE (Debug)

Operands

op
IALL/INJ

Reference (Arm A64 ISA)

Instruction Forms

Encoding	Instruction		ISA		Bit pattern
0xD5097200	BRB <brb_op>{, <Xt>}		A64		1101010100 \| 0 \| 01 \| 001 \| 0111 \| 0010 \| op2 \| Rt

Description

Branch Record Buffer. For more information, see op0==0b01, cache maintenance, TLB maintenance, and address translation instructions.