def carry_from(Rn, operand, size=32):
RnBin = BinStr(Rn, size)
operandBin = BinStr(operand, size)
if int(RnBin.str, 2) + int(operandBin.str, 2) >= 2**size:
return 1
else:
return 0
def borrow_from(Rn, operand, size=32):
RnBin = BinStr(Rn, size)
operandBin = BinStr(operand, size)
if int(RnBin.str, 2) < int(operandBin.str, 2):
return 1
else:
return 0
def _shift_lsr(shift_operand, post_state):
global shifter_carry_out
Rm = get_value(shift_operand[0].strip(','), post_state)
if check_imm(shift_operand[2]):
shift_imm = int(shift_operand[2][1:], 16)
if shift_imm == 0:
shifter_operand = 0
shifter_carry_out = BinStr(Rm)[31]
else:
shifter_operand = Rm >> shift_imm
shifter_carry_out = BinStr(Rm)[shift_imm - 1]
return shifter_operand
elif check_reg(shift_operand[2]):
Rs = get_value(shift_operand[2], post_state)
RsBin = int(BinStr(Rs)[7:0], 2)
if RsBin == 0:
shifter_operand = Rm
shifter_carry_out = post_state[1]['C']
elif RsBin < 32:
shifter_operand = Rm >> RsBin
shifter_carry_out = BinStr(Rm)[RsBin - 1]
elif RsBin == 32:
shift_operand = 0
shifter_carry_out = BinStr(Rm)[31]
else:
shifter_operand = 0
shifter_carry_out = 0
return shifter_operand
else:
print 'shift_lsr ERROR'
return 0
def _shift_imm(shift_operand, post_state):
global shifter_carry_out
print "_shift_imm:",shift_operand
imm = shift_operand[1:]
# print imm
imm_bin = BinStr(int(imm, 16))
immed_8 = int(imm_bin[7:0], 2)
print immed_8
rotate_imm = int(imm_bin[11:8], 2)
shifter_operand = int(cycle_shift(immed_8, rotate_imm*2), 2)
print 'shifter_operand:', shifter_operand
if rotate_imm == 0:
shifter_carry_out = post_state[1]['C']
else:
shifter_carry_out = BinStr(shifter_operand)[31]
return shifter_operand
def _shift_ror(shift_operand, post_state):
global shifter_carry_out
Rm = get_value(shift_operand[0].strip(','), post_state)
if check_imm(shift_operand[2]):
shift_imm = int(shift_operand[2][1:], 16)
if shift_imm == 0:
shifter_operand = post_state[1]['C'] << 31 | Rm >> 1
shifter_carry_out = BinStr(Rm)[0]
else:
shifter_operand = cycle_shift(Rm, shift_imm)
shifter_carry_out = BinStr(Rm)[shift_imm - 1]
return shifter_operand
elif check_reg(shift_operand[2]):
Rs = get_value(shift_operand[2], post_state)
RsBin = int(BinStr(Rs)[4:0], 2)
if int(BinStr(Rs)[7:0], 2) == 0:
shifter_operand = Rm
shifter_carry_out = post_state[1]['C']
elif RsBin == 0:
shifter_operand = Rm
shifter_carry_out = BinStr(Rm)[31]
else:
shifter_operand = cycle_shift(Rm, RsBin)
shifter_carry_out = BinStr(Rm)[RsBin -1]
return shifter_operand
else:
print 'shift_ror ERROR'
return 0
def smull(asm, post_state):
# Signed Multiply Long
# SMULL{<cond>}{S} <RdLo>, <RdHi>, <Rm>, <Rs>
_asm = get_asm(asm)
S = 1 if _asm[0][-1].upper() == 'S' else 0
RdLo = _asm[1].strip(',')
RdHi = _asm[2].strip(',')
Rm = get_value(_asm[3].strip(','), post_state)
Rs = get_value(_asm[4], post_state)
Rdtmp = BinStr(Rm*Rs, 64)
# Singed multiplication
post_state[0][RdHi] = int(Rdtmp[63:33], 2)
post_state[0][RdLo] = int(Rdtmp[31:0], 2)
if S:
handleNZ(Rdtmp, post_state)
def smlal(asm, post_state):
# Signed Multiply Accumulate Long
# SMLAL{<cond>}{S} <RdLo>, <RdHi>, <Rm>, <Rs>
_asm = get_asm(asm)
S = 1 if _asm[0][-1].upper() == 'S' else 0
RdLo = _asm[1].strip(',')
RdHi = _asm[2].strip(',')
Rm = get_value(_asm[3].strip(','), post_state)
Rs = get_value(_asm[4], post_state)
Rdtmp = BinStr(Rm*Rs, 64)
# Signed multiplication
post_state[0][RdLo] = int(Rdtmp[31:0], 2) + post_state[0][RdLo]
post_state[0][RdHi] = int(Rdtmp[63:32], 2) + post_state[0][RdHi] +\
carry_from(int(Rdtmp[31:0], 2), post_state[0][RdLo])
if S:
handleNZ(Rdtmp, post_state)
def over_flow_from(Rn, opt, operand, size=32):
# print 'over_flow_from called.'
if opt == '+':
RnBin = BinStr(Rn, size)
operandBin = BinStr(operand, size)
ResBin = BinStr(Rn + operand, size)
if RnBin.sf == operandBin.sf and RnBin.sf != ResBin.sf:
# print 'return + 1'
return 1
else:
return 0
elif opt == '-':
RnBin = BinStr(Rn, size)
operandBin = BinStr(operand, size)
ResBin = BinStr(Rn - operand, size)
if RnBin.sf != operandBin.sf and RnBin.sf != ResBin.sf:
return 1
else:
return 0
else:
return None
def handleNZ(operand, post_state):
# print('handleNZ called.')
alu_out = BinStr(operand) if type(operand) !=BinStr else operand
post_state[1]['N'] = alu_out[alu_out.size-1]
post_state[1]['Z'] = 1 if alu_out == 0 else 0
def _shift_rrx(shift_operand, post_state):
global shifter_carry_out
Rm = get_value(shift_operand[0].strip(','), post_state)
shifter_operand = post_state[1]['C'] << 31 | Rm >> 1
shifter_carry_out = BinStr(Rm)[0]
return shifter_operand