os.path.join(os.getenv("HOME"), ".bitfields.d")]
class bitfield:
- def __init__(self, start_bit, end_bit, name):
- self.start_bit = start_bit
- self.end_bit = end_bit
+ def __init__(self, bits, name):
+ self.bits = bits
self.name = name
self.values = {}
- def start_bit(self):
- return self.start_bit
-
- def end_bit(self):
- return self.end_bit
-
def width(self):
- return 1 + self.end_bit - self.start_bit
+ return len(self.bits)
def add_value(self, value, description):
self.values[int(value)] = description
def mask(self, reg_width, value):
- shift = (reg_width - 1) - self.end_bit
- return (((2 ** self.width() - 1) << (shift))
- & value) >> shift
+ ret = 0
+ out_len = len(self.bits)
+ for out_bit in range(0, out_len):
+ in_bit = self.bits[out_bit]
+ # shift this bit down to the LSB (and mask the rest)
+ i = (value >> (reg_width - in_bit - 1)) & 1
+ # shift back to the output position in the field
+ i <<= out_len - out_bit - 1
+ ret |= i
+ return ret
def value(self, value):
if value in self.values:
return None
(range_str, name) = a
- range = (None,None)
- if range_str.find(':') != -1:
- r = range_str.split(":")
- range = (int(r[0]),int(r[1]))
- else:
- range = (int(range_str),int(range_str))
-
- return bitfield(range[0], range[1], name)
+ bits = []
+ for s in range_str.split(','):
+ if ':' in s:
+ (start, end) = s.split(':')
+ bits.extend(range(int(start), int(end) + 1, 1))
+ else:
+ bits.append(int(s))
+
+ return bitfield(bits, name)
@staticmethod
def parse_value(line):