Be a little more flexible with order strings

[bitfield] / bitfield

diff --git a/bitfield b/bitfield
index 71e495813fb2bc788f1460e08959e00fdf761e49..3b34aeb5b7514befdd0b9edc277cec373f9997fa 100644 (file)
--- a/bitfield
+++ b/bitfield
@@ -49,7 +49,7 @@ class bitfield:
                return None
 
        @staticmethod
-       def parse_bitfield(line):
+       def parse_bitfield(line, reg):
                a = line.split(None, 1)
                if len(a) != 2:
                        return None
@@ -59,9 +59,11 @@ class bitfield:
                for s in range_str.split(','):
                        if ':' in s:
                                (start, end) = s.split(':')
-                               bits.extend(range(int(start), int(end) + 1, 1))
+                               start = reg.bit_number(int(start))
+                               end = reg.bit_number(int(end))
+                               bits.extend(range(start, end + 1, 1))
                        else:
-                               bits.append(int(s))
+                               bits.append(reg.bit_number(int(s)))
  
                return bitfield(bits, name)
 
@@ -73,11 +75,16 @@ class bitfield:
                return a
 
 class register:
-       def __init__(self, id, name, width):
+       bit_0_is_msb = 0
+       bit_0_is_lsb = 1
+
+       def __init__(self, id):
                self.id = id
-               self.name = name
-               self.width = width
                self.fields = []
+               # set defaults
+               self.name = None
+               self.bit_order = self.bit_0_is_msb
+               self.width = 64
 
        def add_field(self, field):
                self.fields.append(field)
@@ -100,6 +107,11 @@ class register:
                                str += "%*s: 0x%x\n" \
                                        % (name_width, field.name, v)
                return str
+       
+       def bit_number(self, number):
+               if self.bit_order == self.bit_0_is_lsb:
+                       number = self.width - 1 - number
+               return number
 
 def list_regs(regs):
        for (id, r) in regs.iteritems():
@@ -119,6 +131,11 @@ def parse_config(bnf, regs, file):
 
        tokens = bnf.parseString(f.read())
 
+       order_map = {'bit-0-is-lsb':    register.bit_0_is_lsb,
+                       'bit-0-is-msb': register.bit_0_is_msb,
+                       'ibm':          register.bit_0_is_msb,
+                       'default':      register.bit_0_is_msb}
+
        for tok in tokens:
                ts = tok.asList()
                id = ts.pop(0)
@@ -127,20 +144,19 @@ def parse_config(bnf, regs, file):
                        raise ConfigurationError(file,
                                "Register %s is already defined" % id)
 
-               # default to 64 bit registers
-               width = 64
-               name = None
+               reg = register(id)
+
                alias_id = None
                fields = []
 
                for t in ts:
                        if t[0] == 'name':
                                name = t[1]
-                               name = name.strip()
+                               reg.name = name.strip()
                        elif t[0] == 'width':
-                               width = int(t[1])
+                               reg.width = int(t[1])
                        elif t[0] == 'field':
-                               f = bitfield.parse_bitfield(t[1])
+                               f = bitfield.parse_bitfield(t[1], reg)
                                if f is None:
                                        raise ConfigurationError(file,
                                                "Invalid field in %s" % id)
@@ -155,11 +171,26 @@ def parse_config(bnf, regs, file):
                                                "Invalid value in %s" % id)
 
                                fields[-1].add_value(v[0], v[1])
+                       elif t[0] == 'order':
+                               if len(fields) != 0:
+                                       raise ConfigurationError(file,
+                                               ("bit order defined after " \
+                                               + "fields in %s") % id)
+
+                               order_str = t[1].strip().lower()
+                               order_str = order_str.replace(' ', '-')
+
+                               if order_str not in order_map.keys():
+                                       raise ConfigurationError(file,
+                                               "Invalid bit order %s in %s" % \
+                                               (order_str, id))
+                               reg.bit_order = order_map[order_str]
+                               
                        elif t[0] == 'alias':
                                alias_id = t[1].strip()
 
                if alias_id is not None:
-                       if name is not None or fields != []:
+                       if reg.name is not None or fields != []:
                                raise ConfigurationError(file, ("Definiton " \
                                        + "for %s is an alias, but has other " \
                                        + "attributes") % id)
@@ -169,10 +200,10 @@ def parse_config(bnf, regs, file):
                                        "non-existent register %s (from %s)" \
                                        % (alias_id, id))
 
-                       regs[id] = regs[alias_id]
+                       reg = regs[alias_id]
                        continue
 
-               if name is None or name == '':
+               if reg.name is None or reg.name == '':
                        raise ConfigurationError(file,
                                "No name for entry %s" % id)
 
@@ -180,11 +211,10 @@ def parse_config(bnf, regs, file):
                        raise ConfigurationError(file,
                                "Register %s has no fields" % id)
 
-               r = register(id, name, width)
                for f in fields:
-                       r.add_field(f)
+                       reg.add_field(f)
 
-               regs[id] = r
+               regs[id] = reg
 
 def parse_config_dir(data, dir, fnames):
        (bnf, regs) = data