git.ozlabs.org Git - bitfield/blob - bitfield

   1 #!/usr/bin/python2.4
   2 #
   3 # Utility to decode register values
   4 # Copyright (c) 2006 Jeremy Kerr <jk@ozlabs.org>
   5 # Released under the GNU General Public License version 2 or later
   6 #
   7 # Documentation and updates at: http://ozlabs.org/~jk/code/bitfield
   8
   9 import os
  10 import sys
  11 import pprint
  12 from pyparsing import Literal, Word, ZeroOrMore, Group, Dict, Optional, \
  13         printables, ParseException, restOfLine
  14 from getopt import getopt, GetoptError
  15
  16 # List of paths to look for configuration files. If a directory is specified,
  17 # it will be (recursively) scanned for .conf files.
  18 configs = [os.path.join(os.getenv("HOME"), ".bitfields.conf"),
  19                 os.path.join(os.getenv("HOME"), ".bitfields.d")]
  20
  21 class bitfield:
  22         def __init__(self, start_bit, end_bit, name):
  23                 self.start_bit = start_bit
  24                 self.end_bit = end_bit
  25                 self.name = name
  26                 self.values = {}
  27
  28         def start_bit(self):
  29                 return self.start_bit
  30
  31         def end_bit(self):
  32                 return self.end_bit
  33
  34         def width(self):
  35                 return 1 + self.end_bit - self.start_bit
  36
  37         def add_value(self, value, description):
  38                 self.values[int(value)] = description
  39
  40         def mask(self, reg_width, value):
  41                 shift = (reg_width - 1) - self.end_bit
  42                 return (((2 ** self.width() - 1) << (shift))
  43                         & value) >> shift
  44
  45         def value(self, value):
  46                 if value in self.values:
  47                         return self.values[value]
  48                 return None
  49
  50         @staticmethod
  51         def parse_bitfield(line):
  52                 a = line.split(None, 1)
  53                 if len(a) != 2:
  54                         return None
  55                 (range_str, name) = a
  56
  57                 range = (None,None)
  58                 if range_str.find(':') != -1:
  59                         r = range_str.split(":")
  60                         range = (int(r[0]),int(r[1]))
  61                 else:
  62                         range = (int(range_str),int(range_str))
  63
  64                 return bitfield(range[0], range[1], name)
  65
  66         @staticmethod
  67         def parse_value(line):
  68                 a = line.split(None, 1)
  69                 if len(a) != 2:
  70                         return None
  71                 return a
  72
  73 class register:
  74         def __init__(self, id, name, width):
  75                 self.id = id
  76                 self.name = name
  77                 self.width = width
  78                 self.fields = []
  79
  80         def add_field(self, field,):
  81                 self.fields.append(field)
  82
  83         def decode(self, value, ignore_zero):
  84                 field_width = (self.width + 3) / 4
  85                 name_width = max(map(lambda f: len(f.name), self.fields))
  86                 str = "0x%0*lx [%d]\n" % (field_width, value, value)
  87                 for field in self.fields:
  88                         v = field.mask(self.width, value);
  89                         if ignore_zero and v == 0:
  90                                 continue
  91                         desc = field.value(v)
  92                         if desc is not None:
  93                                 str += "%*s: 0x%x [%s]\n" \
  94                                         % (name_width, field.name, v, desc)
  95                         else:
  96                                 str += "%*s: 0x%x\n" \
  97                                         % (name_width, field.name, v)
  98                 return str
  99
 100 def list_regs(regs):
 101         for (id, r) in regs.iteritems():
 102                 print "%18s : %s" % (id, r.name)
 103
 104 def search_regs(regs, str):
 105         return dict((k, regs[k]) for k in regs \
 106                         if str.lower() in regs[k].name.lower() + k.lower())
 107
 108 class ConfigurationError(Exception):
 109         def __init__(self, file, message):
 110                 self.file = file
 111                 self.message = message
 112
 113 def parse_config(bnf, regs, file):
 114         f = open(file)
 115
 116         tokens = bnf.parseString(f.read())
 117
 118         for tok in tokens:
 119                 ts = tok.asList()
 120                 id = ts.pop(0)
 121
 122                 if regs.has_key(id):
 123                         raise ConfigurationError(file,
 124                                 "Register %s is already defined" % id)
 125
 126                 # default to 64 bit registers
 127                 width = 64
 128                 name = None
 129                 fields = []
 130
 131                 for t in ts:
 132                         if t[0] == 'name':
 133                                 name = t[1]
 134                                 name = name.strip()
 135                         elif t[0] == 'width':
 136                                 width = int(t[1])
 137                         elif t[0] == 'field':
 138                                 f = bitfield.parse_bitfield(t[1])
 139                                 if f is None:
 140                                         raise ConfigurationError(file,
 141                                                 "Invalid field in %s" % id)
 142                                 fields.append(f)
 143                         elif t[0] == 'value':
 144                                 if len(fields) == 0:
 145                                         raise ConfigurationError(file,
 146                                                 "No field for value in %s" % id)
 147                                 v = bitfield.parse_value(t[1])
 148                                 if v is None:
 149                                         raise ConfigurationError(file,
 150                                                 "Invalid value in %s" % id)
 151
 152                                 fields[-1].add_value(v[0], v[1])
 153
 154                 if name is None or name == '':
 155                         raise ConfigurationError(file,
 156                                 "No name for entry %s" % id)
 157
 158                 if len(fields) == 0:
 159                         raise ConfigurationError(file,
 160                                 "Register %s has no fields" % id)
 161
 162                 r = register(id, name, width)
 163                 for f in fields:
 164                         r.add_field(f)
 165
 166                 regs[id] = r
 167
 168 def parse_config_dir(data, dir, fnames):
 169         (bnf, regs) = data
 170         for fname in fnames:
 171                 full_fname = os.path.join(dir, fname)
 172
 173                 if os.path.isdir(full_fname):
 174                         continue
 175
 176                 if fname.endswith('.conf'):
 177                         parse_config(bnf, regs, full_fname)
 178
 179 def parse_all_configs(configs):
 180         regs = {}
 181
 182         # set up the bnf to be used for each file
 183         lbrack = Literal("[").suppress()
 184         rbrack = Literal("]").suppress()
 185         colon  = Literal(":").suppress()
 186         semi   = Literal(";")
 187
 188         comment = semi + Optional(restOfLine)
 189
 190         nonrbrack = "".join([c for c in printables if c != "]"]) + " \t"
 191         noncolon  = "".join([c for c in printables if c != ":"]) + " \t"
 192
 193         sectionDef = lbrack + Word(nonrbrack) + rbrack
 194         keyDef = ~lbrack + Word(noncolon) + colon + restOfLine
 195
 196         bnf = Dict(ZeroOrMore(Group(sectionDef + ZeroOrMore(Group(keyDef)))))
 197         bnf.ignore(comment)
 198
 199         # bundle into a single var that can be passed to os.path.walk
 200         conf_data = (bnf, regs)
 201
 202         for conf in configs:
 203                 if not os.path.exists(conf):
 204                         continue
 205                 if os.path.isdir(conf):
 206                         os.path.walk(conf, parse_config_dir, conf_data)
 207                 else:
 208                         parse_config(bnf, regs, conf)
 209         return regs
 210
 211 def usage(prog):
 212         print "Usage: %s <-l> | <-s pattern> | [-n] register [value...]" % prog
 213
 214 def decode_value(reg, value, options):
 215         try:
 216                 i = long(value, 0)
 217         except ValueError, e:
 218                 print "error: invalid value '%s'" % value
 219                 return
 220
 221         if i > ((1 << reg.width) - 1):
 222                 print ("error: value '%s' is too large " + \
 223                         "for %d-bit register '%s'") % (value, reg.width, reg.id)
 224                 return
 225
 226         print reg.decode(i, options.has_key('non_zero'))
 227
 228
 229 def main():
 230         try:
 231                 (opts, args) = getopt(sys.argv[1:], "hlns:", \
 232                         ["help", "list", "non-zero", "search="])
 233         except GetoptError:
 234                 usage(sys.argv[0])
 235                 return 1
 236
 237         try:
 238                 regs = parse_all_configs(configs)
 239         except ConfigurationError, e:
 240                 print "Error parsing configuration file %s:\n\t%s" % \
 241                         (e.file, e.message)
 242                 return 1
 243
 244         if regs == {}:
 245                 print "No configuration available"
 246                 return 1
 247
 248         options = {}
 249         options['non-zero'] = False
 250
 251         for o, a in opts:
 252                 if o in ("-h", "--help"):
 253                         usage(sys.argv[0])
 254                         return
 255
 256                 if o in ("-l", "--list"):
 257                         list_regs(regs)
 258                         return
 259
 260                 if o in ("-s", "--search"):
 261                         list_regs(search_regs(regs, a))
 262                         return
 263
 264                 if o in ("-n", "--non-zero"):
 265                         options['non-zero'] = True
 266
 267         if not args:
 268                 usage(sys.argv[0])
 269                 return 1
 270
 271         reg_id = args.pop(0)
 272         if not regs.has_key(reg_id):
 273                 print "No such register '%s'" % reg_id
 274                 return 1
 275
 276         r = regs[reg_id]
 277         print "decoding as %s" % r.name
 278
 279         if args:
 280                 values = args
 281         else:
 282                 try:
 283                         values = sys.stdin.readlines()
 284                 except KeyboardInterrupt, e:
 285                         return
 286
 287         for value in values:
 288                 decode_value(r, value.strip(), options)
 289
 290         return 0
 291
 292 if __name__ == "__main__":
 293         sys.exit(main())