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
  87                 str = "0x%0*lx [%d]\n" % (field_width, value, value)
  88
  89                 for field in self.fields:
  90                         v = field.mask(self.width, value);
  91                         if ignore_zero and v == 0:
  92                                 continue
  93                         desc = field.value(v)
  94                         if desc is not None:
  95                                 str += "%*s: 0x%x [%s]\n" \
  96                                         % (name_width, field.name, v, desc)
  97                         else:
  98                                 str += "%*s: 0x%x\n" \
  99                                         % (name_width, field.name, v)
 100                 return str
 101
 102 def list_regs(regs):
 103         for (id, r) in regs.iteritems():
 104                 print "%18s : %s" % (id, r.name)
 105
 106 def search_regs(regs, str):
 107         return dict((k, regs[k]) for k in regs \
 108                         if str.lower() in regs[k].name.lower() + k.lower())
 109
 110 class ConfigurationError(Exception):
 111         def __init__(self, file, message):
 112                 self.file = file
 113                 self.message = message
 114
 115 def parse_config(bnf, regs, file):
 116         f = open(file)
 117
 118         tokens = bnf.parseString(f.read())
 119
 120         for tok in tokens:
 121                 ts = tok.asList()
 122                 id = ts.pop(0)
 123
 124                 if regs.has_key(id):
 125                         raise ConfigurationError(file,
 126                                 "Register %s is already defined" % id)
 127
 128                 # default to 64 bit registers
 129                 width = 64
 130                 name = None
 131                 fields = []
 132
 133                 for t in ts:
 134                         if t[0] == 'name':
 135                                 name = t[1]
 136                                 name = name.strip()
 137                         elif t[0] == 'width':
 138                                 width = int(t[1])
 139                         elif t[0] == 'field':
 140                                 f = bitfield.parse_bitfield(t[1])
 141                                 if f is None:
 142                                         raise ConfigurationError(file,
 143                                                 "Invalid field in %s" % id)
 144                                 fields.append(f)
 145                         elif t[0] == 'value':
 146                                 if len(fields) == 0:
 147                                         raise ConfigurationError(file,
 148                                                 "No field for value in %s" % id)
 149                                 v = bitfield.parse_value(t[1])
 150                                 if v is None:
 151                                         raise ConfigurationError(file,
 152                                                 "Invalid value in %s" % id)
 153
 154                                 fields[-1].add_value(v[0], v[1])
 155
 156                 if name is None or name == '':
 157                         raise ConfigurationError(file,
 158                                 "No name for entry %s" % id)
 159
 160                 if len(fields) == 0:
 161                         raise ConfigurationError(file,
 162                                 "Register %s has no fields" % id)
 163
 164                 r = register(id, name, width)
 165                 for f in fields:
 166                         r.add_field(f)
 167
 168                 regs[id] = r
 169
 170 def parse_config_dir(data, dir, fnames):
 171         (bnf, regs) = data
 172         for fname in fnames:
 173                 full_fname = os.path.join(dir, fname)
 174
 175                 if os.path.isdir(full_fname):
 176                         continue
 177
 178                 if fname.endswith('.conf'):
 179                         parse_config(bnf, regs, full_fname)
 180
 181 def parse_all_configs(configs):
 182         regs = {}
 183
 184         # set up the bnf to be used for each file
 185         lbrack = Literal("[").suppress()
 186         rbrack = Literal("]").suppress()
 187         colon  = Literal(":").suppress()
 188         semi   = Literal(";")
 189
 190         comment = semi + Optional(restOfLine)
 191
 192         nonrbrack = "".join([c for c in printables if c != "]"]) + " \t"
 193         noncolon  = "".join([c for c in printables if c != ":"]) + " \t"
 194
 195         sectionDef = lbrack + Word(nonrbrack) + rbrack
 196         keyDef = ~lbrack + Word(noncolon) + colon + restOfLine
 197
 198         bnf = Dict(ZeroOrMore(Group(sectionDef + ZeroOrMore(Group(keyDef)))))
 199         bnf.ignore(comment)
 200
 201         # bundle into a single var that can be passed to os.path.walk
 202         conf_data = (bnf, regs)
 203
 204         for conf in configs:
 205                 if not os.path.exists(conf):
 206                         continue
 207                 if os.path.isdir(conf):
 208                         os.path.walk(conf, parse_config_dir, conf_data)
 209                 else:
 210                         parse_config(bnf, regs, conf)
 211         return regs
 212
 213 def usage(prog):
 214         print "Usage: %s <-l> | <-s pattern> | [-n] register [value...]" % prog
 215
 216 def decode_value(reg, value, options):
 217         try:
 218                 i = long(value, 0)
 219         except ValueError, e:
 220                 print "error: invalid value '%s'" % value
 221                 return
 222
 223         if i > ((1 << reg.width) - 1):
 224                 print ("error: value '%s' is too large " + \
 225                         "for %d-bit register '%s'") % (value, reg.width, reg.id)
 226                 return
 227
 228         print reg.decode(i, options.has_key('non_zero'))
 229
 230
 231 def main():
 232         try:
 233                 (opts, args) = getopt(sys.argv[1:], "hlns:", \
 234                         ["help", "list", "non-zero", "search="])
 235         except GetoptError:
 236                 usage(sys.argv[0])
 237                 return 1
 238
 239         try:
 240                 regs = parse_all_configs(configs)
 241         except ConfigurationError, e:
 242                 print "Error parsing configuration file %s:\n\t%s" % \
 243                         (e.file, e.message)
 244                 return 1
 245
 246         if regs == {}:
 247                 print "No configuration available"
 248                 return 1
 249
 250         options = {}
 251         options['non-zero'] = False
 252
 253         for o, a in opts:
 254                 if o in ("-h", "--help"):
 255                         usage(sys.argv[0])
 256                         return
 257
 258                 if o in ("-l", "--list"):
 259                         list_regs(regs)
 260                         return
 261
 262                 if o in ("-s", "--search"):
 263                         list_regs(search_regs(regs, a))
 264                         return
 265
 266                 if o in ("-n", "--non-zero"):
 267                         options['non-zero'] = True
 268
 269         if not args:
 270                 usage(sys.argv[0])
 271                 return 1
 272
 273         reg_id = args.pop(0)
 274         if not regs.has_key(reg_id):
 275                 print "No such register '%s'" % reg_id
 276                 return 1
 277
 278         r = regs[reg_id]
 279         print "decoding as %s" % r.name
 280
 281         if args:
 282                 values = args
 283         else:
 284                 try:
 285                         values = sys.stdin.readlines()
 286                 except KeyboardInterrupt, e:
 287                         return
 288
 289         for value in values:
 290                 decode_value(r, value.strip(), options)
 291
 292         return 0
 293
 294 if __name__ == "__main__":
 295         sys.exit(main())