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 = ["/etc/bitfield.d", "/etc/bitfield",
  19                 os.path.join(os.getenv("HOME"), ".bitfield.d"),
  20                 os.path.join(os.getenv("HOME"), ".bitfield.conf")]
  21
  22 class bitfield:
  23         def __init__(self, bits, name):
  24                 self.bits = bits
  25                 self.name = name
  26                 self.values = {}
  27
  28         def width(self):
  29                 return len(self.bits)
  30
  31         def add_value(self, value, description):
  32                 self.values[int(value)] = description
  33
  34         def mask(self, reg_width, value):
  35                 ret = 0
  36                 out_len = len(self.bits)
  37                 for out_bit in range(0, out_len):
  38                         in_bit = self.bits[out_bit]
  39                         # shift this bit down to the LSB (and mask the rest)
  40                         i = (value >> (reg_width - in_bit - 1)) & 1
  41                         # shift back to the output position in the field
  42                         i <<= out_len - out_bit - 1
  43                         ret |= i
  44                 return ret
  45
  46         def value(self, value):
  47                 if value in self.values:
  48                         return self.values[value]
  49                 return None
  50
  51         @staticmethod
  52         def parse_bitfield(line):
  53                 a = line.split(None, 1)
  54                 if len(a) != 2:
  55                         return None
  56                 (range_str, name) = a
  57
  58                 bits = []
  59                 for s in range_str.split(','):
  60                         if ':' in s:
  61                                 (start, end) = s.split(':')
  62                                 bits.extend(range(int(start), int(end) + 1, 1))
  63                         else:
  64                                 bits.append(int(s))
  65
  66                 return bitfield(bits, name)
  67
  68         @staticmethod
  69         def parse_value(line):
  70                 a = line.split(None, 1)
  71                 if len(a) != 2:
  72                         return None
  73                 return a
  74
  75 class register:
  76         def __init__(self, id, name, width):
  77                 self.id = id
  78                 self.name = name
  79                 self.width = width
  80                 self.fields = []
  81
  82         def add_field(self, field):
  83                 self.fields.append(field)
  84
  85         def decode(self, value, ignore_zero):
  86                 field_width = (self.width + 3) / 4
  87                 name_width = max(map(lambda f: len(f.name), self.fields))
  88
  89                 str = "0x%0*lx [%d]\n" % (field_width, value, value)
  90
  91                 for field in self.fields:
  92                         v = field.mask(self.width, value);
  93                         if ignore_zero and v == 0:
  94                                 continue
  95                         desc = field.value(v)
  96                         if desc is not None:
  97                                 str += "%*s: 0x%x [%s]\n" \
  98                                         % (name_width, field.name, v, desc)
  99                         else:
 100                                 str += "%*s: 0x%x\n" \
 101                                         % (name_width, field.name, v)
 102                 return str
 103
 104 def list_regs(regs):
 105         for (id, r) in regs.iteritems():
 106                 print "%18s : %s" % (id, r.name)
 107
 108 def search_regs(regs, str):
 109         return dict((k, regs[k]) for k in regs \
 110                         if str.lower() in regs[k].name.lower() + k.lower())
 111
 112 class ConfigurationError(Exception):
 113         def __init__(self, file, message):
 114                 self.file = file
 115                 self.message = message
 116
 117 def parse_config(bnf, regs, file):
 118         f = open(file)
 119
 120         tokens = bnf.parseString(f.read())
 121
 122         for tok in tokens:
 123                 ts = tok.asList()
 124                 id = ts.pop(0)
 125
 126                 if regs.has_key(id):
 127                         raise ConfigurationError(file,
 128                                 "Register %s is already defined" % id)
 129
 130                 # default to 64 bit registers
 131                 width = 64
 132                 name = None
 133                 fields = []
 134
 135                 for t in ts:
 136                         if t[0] == 'name':
 137                                 name = t[1]
 138                                 name = name.strip()
 139                         elif t[0] == 'width':
 140                                 width = int(t[1])
 141                         elif t[0] == 'field':
 142                                 f = bitfield.parse_bitfield(t[1])
 143                                 if f is None:
 144                                         raise ConfigurationError(file,
 145                                                 "Invalid field in %s" % id)
 146                                 fields.append(f)
 147                         elif t[0] == 'value':
 148                                 if len(fields) == 0:
 149                                         raise ConfigurationError(file,
 150                                                 "No field for value in %s" % id)
 151                                 v = bitfield.parse_value(t[1])
 152                                 if v is None:
 153                                         raise ConfigurationError(file,
 154                                                 "Invalid value in %s" % id)
 155
 156                                 fields[-1].add_value(v[0], v[1])
 157
 158                 if name is None or name == '':
 159                         raise ConfigurationError(file,
 160                                 "No name for entry %s" % id)
 161
 162                 if len(fields) == 0:
 163                         raise ConfigurationError(file,
 164                                 "Register %s has no fields" % id)
 165
 166                 r = register(id, name, width)
 167                 for f in fields:
 168                         r.add_field(f)
 169
 170                 regs[id] = r
 171
 172 def parse_config_dir(data, dir, fnames):
 173         (bnf, regs) = data
 174         for fname in fnames:
 175                 full_fname = os.path.join(dir, fname)
 176
 177                 if os.path.isdir(full_fname):
 178                         continue
 179
 180                 if fname.endswith('.conf'):
 181                         parse_config(bnf, regs, full_fname)
 182
 183 def parse_all_configs(configs):
 184         regs = {}
 185
 186         # set up the bnf to be used for each file
 187         lbrack = Literal("[").suppress()
 188         rbrack = Literal("]").suppress()
 189         colon  = Literal(":").suppress()
 190         semi   = Literal(";")
 191
 192         comment = semi + Optional(restOfLine)
 193
 194         nonrbrack = "".join([c for c in printables if c != "]"]) + " \t"
 195         noncolon  = "".join([c for c in printables if c != ":"]) + " \t"
 196
 197         sectionDef = lbrack + Word(nonrbrack) + rbrack
 198         keyDef = ~lbrack + Word(noncolon) + colon + restOfLine
 199
 200         bnf = Dict(ZeroOrMore(Group(sectionDef + ZeroOrMore(Group(keyDef)))))
 201         bnf.ignore(comment)
 202
 203         # bundle into a single var that can be passed to os.path.walk
 204         conf_data = (bnf, regs)
 205
 206         for conf in configs:
 207                 if not os.path.exists(conf):
 208                         continue
 209                 if os.path.isdir(conf):
 210                         os.path.walk(conf, parse_config_dir, conf_data)
 211                 else:
 212                         parse_config(bnf, regs, conf)
 213         return regs
 214
 215 def usage(prog):
 216         print "Usage: %s <-l> | <-s pattern> | [-n] register [value...]" % prog
 217
 218 def decode_value(reg, value, options):
 219         try:
 220                 i = long(value, 0)
 221         except ValueError, e:
 222                 print "error: invalid value '%s'" % value
 223                 return
 224
 225         if i > ((1 << reg.width) - 1):
 226                 print ("error: value '%s' is too large " + \
 227                         "for %d-bit register '%s'") % (value, reg.width, reg.id)
 228                 return
 229
 230         print reg.decode(i, options['non-zero'])
 231
 232
 233 def main():
 234         try:
 235                 (opts, args) = getopt(sys.argv[1:], "hlns:", \
 236                         ["help", "list", "non-zero", "search="])
 237         except GetoptError:
 238                 usage(sys.argv[0])
 239                 return 1
 240
 241         try:
 242                 regs = parse_all_configs(configs)
 243         except ConfigurationError, e:
 244                 print "Error parsing configuration file %s:\n\t%s" % \
 245                         (e.file, e.message)
 246                 return 1
 247
 248         if regs == {}:
 249                 print "No configuration available"
 250                 return 1
 251
 252         options = {}
 253         options['non-zero'] = False
 254
 255         for o, a in opts:
 256                 if o in ("-h", "--help"):
 257                         usage(sys.argv[0])
 258                         return
 259
 260                 if o in ("-l", "--list"):
 261                         list_regs(regs)
 262                         return
 263
 264                 if o in ("-s", "--search"):
 265                         list_regs(search_regs(regs, a))
 266                         return
 267
 268                 if o in ("-n", "--non-zero"):
 269                         options['non-zero'] = True
 270
 271         if not args:
 272                 usage(sys.argv[0])
 273                 return 1
 274
 275         reg_id = args.pop(0)
 276         if not regs.has_key(reg_id):
 277                 print "No such register '%s'" % reg_id
 278                 return 1
 279
 280         reg = regs[reg_id]
 281         print "decoding as %s" % reg.name
 282
 283         if args:
 284                 value_iter = args.__iter__()
 285         else:
 286                 value_iter = iter(sys.stdin.readline, '')
 287
 288         try:
 289                 for value in value_iter:
 290                         decode_value(reg, value.strip(), options)
 291         except KeyboardInterrupt, e:
 292                 pass
 293
 294         return 0
 295
 296 if __name__ == "__main__":
 297         sys.exit(main())