arm64_msr.py

arm64_msr.py

import struct

Op0_shift = 19
Op1_shift = 16
CRn_shift = 12
CRm_shift = 8
Op2_shift = 5

MAX_OP0   = 3
MAX_OP1   = 7
MAX_OP2   = 7
MAX_CN    = 15
MAX_CM    = 15
MAX_REG   = 31

def sys_reg(op0, op1, cn, cm, op2):
  assert ((op0 <= MAX_OP0) and (op1 <= MAX_OP1) and (op2 <= MAX_OP2)
      and (cn  <= MAX_CN)  and (cm  <= MAX_CM))
  return (((op0) << Op0_shift) | ((op1) << Op1_shift) |
          ((cn)  << CRn_shift) | ((cm)  << CRm_shift) |
          ((op2) << Op2_shift))

def msr_insn(sysreg: int, reg: int):
    assert (reg <= 31 and reg >= 0)
    return (0xd5000000 | sysreg | reg)

def mrs_insn(reg: int, sysreg: int):
    assert (reg <= 31 and reg >= 0)
    return (0xd5200000 | sysreg | reg)

if __name == '__main__':
  print(struct.pack("<L", msr_insn(sys_reg(0, 1, 1, 1, 1), 1)).hex())
  print(struct.pack("<L", mrs_insn(1, sys_reg(0, 1, 1, 1, 1))).hex())