Add support for non-contiguous bitfields.

[bitfield] / bitfield

diff --git a/bitfield b/bitfield
index 3651677f86c29ab8a90d9a67df14fa086ffa4503..c70c6c6af86f2682906936f7d5338245031eb87d 100644 (file)
--- a/bitfield
+++ b/bitfield
@@ -19,28 +19,28 @@ configs = [os.path.join(os.getenv("HOME"), ".bitfields.conf"),
                os.path.join(os.getenv("HOME"), ".bitfields.d")]
 
 class bitfield:
                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 = {}
 
                self.name = name
                self.values = {}
 

-       def start_bit(self):
-               return self.start_bit
-
-       def end_bit(self):
-               return self.end_bit
-

        def width(self):
        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):
 
        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:
 
        def value(self, value):
                if value in self.values:


@@ -54,14 +54,15 @@ class bitfield:
                        return None
                (range_str, name) = a
 
                        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):
 
        @staticmethod
        def parse_value(line):


@@ -275,19 +276,19 @@ def main():
                print "No such register '%s'" % reg_id
                return 1
 
                print "No such register '%s'" % reg_id
                return 1
 

-       r = regs[reg_id]
-       print "decoding as %s" % r.name
+       reg = regs[reg_id]
+       print "decoding as %s" % reg.name

 
        if args:
 
        if args:

-               values = args
+               value_iter = args.__iter__()

        else:
        else:

-               try:
-                       values = sys.stdin.readlines()
-               except KeyboardInterrupt, e:
-                       return
-
-       for value in values:
-               decode_value(r, value.strip(), options)
+               value_iter = iter(sys.stdin.readline, '')
+               
+       try:
+               for value in value_iter:
+                       decode_value(reg, value.strip(), options)
+       except KeyboardInterrupt, e:
+               pass

 
        return 0
 
 
        return 0