Add support for aliased definitions.
[bitfield] / bitfield
index 1a03ddb96419c9f2f77ea08830a21c6d25665d14..71e495813fb2bc788f1460e08959e00fdf761e49 100644 (file)
--- a/bitfield
+++ b/bitfield
@@ -15,32 +15,33 @@ from getopt import getopt, GetoptError
 
 # List of paths to look for configuration files. If a directory is specified,
 # it will be (recursively) scanned for .conf files.
-configs = [os.path.join(os.getenv("HOME"), ".bitfields.conf"),
-               os.path.join(os.getenv("HOME"), ".bitfields.d")]
+configs = ["/etc/bitfield.d", "/etc/bitfield",
+               os.path.join(os.getenv("HOME"), ".bitfield.d"),
+               os.path.join(os.getenv("HOME"), ".bitfield.conf")]
 
 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:
@@ -54,14 +55,15 @@ class bitfield:
                        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):
@@ -128,6 +130,7 @@ def parse_config(bnf, regs, file):
                # default to 64 bit registers
                width = 64
                name = None
+               alias_id = None
                fields = []
 
                for t in ts:
@@ -152,6 +155,22 @@ def parse_config(bnf, regs, file):
                                                "Invalid value in %s" % id)
 
                                fields[-1].add_value(v[0], v[1])
+                       elif t[0] == 'alias':
+                               alias_id = t[1].strip()
+
+               if alias_id is not None:
+                       if name is not None or fields != []:
+                               raise ConfigurationError(file, ("Definiton " \
+                                       + "for %s is an alias, but has other " \
+                                       + "attributes") % id)
+
+                       if not regs.has_key(alias_id):
+                               raise ConfigurationError(file, "Aliasing "
+                                       "non-existent register %s (from %s)" \
+                                       % (alias_id, id))
+
+                       regs[id] = regs[alias_id]
+                       continue
 
                if name is None or name == '':
                        raise ConfigurationError(file,
@@ -225,7 +244,7 @@ def decode_value(reg, value, options):
                        "for %d-bit register '%s'") % (value, reg.width, reg.id)
                return
 
-       print reg.decode(i, options.has_key('non_zero'))
+       print reg.decode(i, options['non-zero'])
 
 
 def main():