def jumping_address(self):
if self._jumping_address is None:
# On the other hand, one can compute the jumping address
address = self.encoding & Bits.set(23, 0)
if Bits.is_on(address, 23):
address |= Bits.set(29, 24)
address = (address << 2)
address += self.address + 8
address &= 0xffffffff
self._jumping_address = address
return self._jumping_address
class AOpType(object):
"""
ARM Opcodes types. The cryptic AOpType name is to have short code
"""
ALWAYS = Bits.set(31, 29)
COND_ALWAYS = 0b1110
LOAD_STORE_MULTIPLE = Bits.on(27)
LOAD_STORE = Bits.on(26)
LOAD_STORE_OFFSET = Bits.set(26, 25)
SOFT_INTERRUPT = 0xF000000
BRANCH = 0xA000000
DATA_PROCESSING = 0x0
DATA_PROCESSING_IMMEDIATE = 0x2000000
def jumping_address(self):
"""
Jumping address for branching instructions
"""
if self.is_branch:
if self._jumping_address is None:
# On the other hand, one can compute the jumping address
address = self.encoding & Bits.set(23, 0)
if Bits.is_on(address, 23):
address |= Bits.set(29, 24)
address = (address << 2)
address += self.address + 8
address &= 0xffffffff
self._jumping_address = address
return self._jumping_address
return None
def opcode_field(self):
"""
Return the instruction part of the opcode for an ARM instruction (See the 'ARM ARM')
:return: A number with the instruction part
"""
t = self.opcode_type()
if t in [AOpType.BRANCH, AOpType.SOFT_INTERRUPT]:
return t
return self.encoding & Bits.set(24, 21)
def test_corrupt_bits(self):
# ldr r5, [pc, #44]
corrupted = corrupt_bits(31, 28, 2, 0xe59f502c)
self.assertEqual(4, len(corrupted))
mask = Bits.set(31, 28)
self.assertTrue(corrupted[0] & mask == AOpType.ALWAYS)
self.assertFalse(corrupted[1] & mask == AOpType.ALWAYS)
self.assertFalse(corrupted[2] & mask == AOpType.ALWAYS)
self.assertFalse(corrupted[3] & mask == AOpType.ALWAYS)
def test_corrupt_conditional(self):
# ldr r5, [pc, #44]
corrupted = corrupt_conditional(2, 0xe59f502c)
self.assertEqual(4, len(corrupted))
mask = Bits.set(31, 28)
self.assertTrue((corrupted[0] & mask) == AOpType.ALWAYS)
self.assertFalse((corrupted[1] & mask) == AOpType.ALWAYS,
"{:b} - {:b}".format(corrupted[1], AOpType.ALWAYS))
self.assertFalse((corrupted[2] & mask) == AOpType.ALWAYS,
"{:b} - {:b}".format(corrupted[2], AOpType.ALWAYS))
self.assertFalse((corrupted[3] & mask) == AOpType.ALWAYS,
"{:b} - {:b}".format(corrupted[3], AOpType.ALWAYS))
def _rs_field_(self):
"""
Returns the Rd register field
"""
return (self.encoding & Bits.set(11, 8)) >> 8
def _rd_field_(self):
"""
Returns the Rd register field
"""
return (self.encoding & Bits.set(15, 12)) >> 12
def _rn_field_(self):
"""
Returns the Rn register field
"""
return (self.encoding & Bits.set(19, 16)) >> 16
def test_set(self):
self.assertEqual(0xE0000000, Bits.set(31, 29))