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, reg):
  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                                 start = reg.bit_number(int(start))
  63                                 end = reg.bit_number(int(end))
  64                                 bits.extend(range(start, end + 1, 1))
  65                         else:
  66                                 bits.append(reg.bit_number(int(s)))
  67
  68                 return bitfield(bits, name)
  69
  70         @staticmethod
  71         def parse_value(line):
  72                 a = line.split(None, 1)
  73                 if len(a) != 2:
  74                         return None
  75                 return a
  76
  77 class register:
  78         bit_0_is_msb = 0
  79         bit_0_is_lsb = 1
  80
  81         def __init__(self, id):
  82                 self.id = id
  83                 self.fields = []
  84                 # set defaults
  85                 self.name = None
  86                 self.bit_order = self.bit_0_is_msb
  87                 self.width = 64
  88
  89         def add_field(self, field):
  90                 self.fields.append(field)
  91
  92         def decode(self, value, ignore_zero):
  93                 field_width = (self.width + 3) / 4
  94                 name_width = max(map(lambda f: len(f.name), self.fields))
  95
  96                 str = "0x%0*lx [%d]\n" % (field_width, value, value)
  97
  98                 for field in self.fields:
  99                         v = field.mask(self.width, value);
 100                         if ignore_zero and v == 0:
 101                                 continue
 102                         desc = field.value(v)
 103                         if desc is not None:
 104                                 str += "%*s: 0x%x [%s]\n" \
 105                                         % (name_width, field.name, v, desc)
 106                         else:
 107                                 str += "%*s: 0x%x\n" \
 108                                         % (name_width, field.name, v)
 109                 return str
 110
 111         def bit_number(self, number):
 112                 if self.bit_order == self.bit_0_is_lsb:
 113                         number = self.width - 1 - number
 114                 return number
 115
 116 def list_regs(regs):
 117         for (id, r) in regs.iteritems():
 118                 print "%18s : %s" % (id, r.name)
 119
 120 def search_regs(regs, str):
 121         return dict((k, regs[k]) for k in regs \
 122                         if str.lower() in regs[k].name.lower() + k.lower())
 123
 124 class ConfigurationError(Exception):
 125         def __init__(self, file, message):
 126                 self.file = file
 127                 self.message = message
 128
 129 def parse_config(bnf, regs, file):
 130         f = open(file)
 131
 132         tokens = bnf.parseString(f.read())
 133
 134         order_map = {'bit-0-is-lsb':    register.bit_0_is_lsb,
 135                         'bit-0-is-msb': register.bit_0_is_msb,
 136                         'ibm':          register.bit_0_is_msb,
 137                         'default':      register.bit_0_is_msb}
 138
 139         for tok in tokens:
 140                 ts = tok.asList()
 141                 id = ts.pop(0)
 142
 143                 if regs.has_key(id):
 144                         raise ConfigurationError(file,
 145                                 "Register %s is already defined" % id)
 146
 147                 reg = register(id)
 148
 149                 alias_id = None
 150                 fields = []
 151
 152                 for t in ts:
 153                         if t[0] == 'name':
 154                                 name = t[1]
 155                                 reg.name = name.strip()
 156                         elif t[0] == 'width':
 157                                 reg.width = int(t[1])
 158                         elif t[0] == 'field':
 159                                 f = bitfield.parse_bitfield(t[1], reg)
 160                                 if f is None:
 161                                         raise ConfigurationError(file,
 162                                                 "Invalid field in %s" % id)
 163                                 fields.append(f)
 164                         elif t[0] == 'value':
 165                                 if len(fields) == 0:
 166                                         raise ConfigurationError(file,
 167                                                 "No field for value in %s" % id)
 168                                 v = bitfield.parse_value(t[1])
 169                                 if v is None:
 170                                         raise ConfigurationError(file,
 171                                                 "Invalid value in %s" % id)
 172
 173                                 fields[-1].add_value(v[0], v[1])
 174                         elif t[0] == 'order':
 175                                 if len(fields) != 0:
 176                                         raise ConfigurationError(file,
 177                                                 ("bit order defined after " \
 178                                                 + "fields in %s") % id)
 179
 180                                 order_str = t[1].strip().lower()
 181                                 if order_str not in order_map.keys():
 182                                         raise ConfigurationError(file,
 183                                                 "Invalid bit order %s in %s" % \
 184                                                 (order_str, id))
 185                                 reg.bit_order = order_map[order_str]
 186
 187                         elif t[0] == 'alias':
 188                                 alias_id = t[1].strip()
 189
 190                 if alias_id is not None:
 191                         if reg.name is not None or fields != []:
 192                                 raise ConfigurationError(file, ("Definiton " \
 193                                         + "for %s is an alias, but has other " \
 194                                         + "attributes") % id)
 195
 196                         if not regs.has_key(alias_id):
 197                                 raise ConfigurationError(file, "Aliasing "
 198                                         "non-existent register %s (from %s)" \
 199                                         % (alias_id, id))
 200
 201                         reg = regs[alias_id]
 202                         continue
 203
 204                 if reg.name is None or reg.name == '':
 205                         raise ConfigurationError(file,
 206                                 "No name for entry %s" % id)
 207
 208                 if len(fields) == 0:
 209                         raise ConfigurationError(file,
 210                                 "Register %s has no fields" % id)
 211
 212                 for f in fields:
 213                         reg.add_field(f)
 214
 215                 regs[id] = reg
 216
 217 def parse_config_dir(data, dir, fnames):
 218         (bnf, regs) = data
 219         for fname in fnames:
 220                 full_fname = os.path.join(dir, fname)
 221
 222                 if os.path.isdir(full_fname):
 223                         continue
 224
 225                 if fname.endswith('.conf'):
 226                         parse_config(bnf, regs, full_fname)
 227
 228 def parse_all_configs(configs):
 229         regs = {}
 230
 231         # set up the bnf to be used for each file
 232         lbrack = Literal("[").suppress()
 233         rbrack = Literal("]").suppress()
 234         colon  = Literal(":").suppress()
 235         semi   = Literal(";")
 236
 237         comment = semi + Optional(restOfLine)
 238
 239         nonrbrack = "".join([c for c in printables if c != "]"]) + " \t"
 240         noncolon  = "".join([c for c in printables if c != ":"]) + " \t"
 241
 242         sectionDef = lbrack + Word(nonrbrack) + rbrack
 243         keyDef = ~lbrack + Word(noncolon) + colon + restOfLine
 244
 245         bnf = Dict(ZeroOrMore(Group(sectionDef + ZeroOrMore(Group(keyDef)))))
 246         bnf.ignore(comment)
 247
 248         # bundle into a single var that can be passed to os.path.walk
 249         conf_data = (bnf, regs)
 250
 251         for conf in configs:
 252                 if not os.path.exists(conf):
 253                         continue
 254                 if os.path.isdir(conf):
 255                         os.path.walk(conf, parse_config_dir, conf_data)
 256                 else:
 257                         parse_config(bnf, regs, conf)
 258         return regs
 259
 260 def usage(prog):
 261         print "Usage: %s <-l> | <-s pattern> | [-n] register [value...]" % prog
 262
 263 def decode_value(reg, value, options):
 264         try:
 265                 i = long(value, 0)
 266         except ValueError, e:
 267                 print "error: invalid value '%s'" % value
 268                 return
 269
 270         if i > ((1 << reg.width) - 1):
 271                 print ("error: value '%s' is too large " + \
 272                         "for %d-bit register '%s'") % (value, reg.width, reg.id)
 273                 return
 274
 275         print reg.decode(i, options['non-zero'])
 276
 277
 278 def main():
 279         try:
 280                 (opts, args) = getopt(sys.argv[1:], "hlns:", \
 281                         ["help", "list", "non-zero", "search="])
 282         except GetoptError:
 283                 usage(sys.argv[0])
 284                 return 1
 285
 286         try:
 287                 regs = parse_all_configs(configs)
 288         except ConfigurationError, e:
 289                 print "Error parsing configuration file %s:\n\t%s" % \
 290                         (e.file, e.message)
 291                 return 1
 292
 293         if regs == {}:
 294                 print "No configuration available"
 295                 return 1
 296
 297         options = {}
 298         options['non-zero'] = False
 299
 300         for o, a in opts:
 301                 if o in ("-h", "--help"):
 302                         usage(sys.argv[0])
 303                         return
 304
 305                 if o in ("-l", "--list"):
 306                         list_regs(regs)
 307                         return
 308
 309                 if o in ("-s", "--search"):
 310                         list_regs(search_regs(regs, a))
 311                         return
 312
 313                 if o in ("-n", "--non-zero"):
 314                         options['non-zero'] = True
 315
 316         if not args:
 317                 usage(sys.argv[0])
 318                 return 1
 319
 320         reg_id = args.pop(0)
 321         if not regs.has_key(reg_id):
 322                 print "No such register '%s'" % reg_id
 323                 return 1
 324
 325         reg = regs[reg_id]
 326         print "decoding as %s" % reg.name
 327
 328         if args:
 329                 value_iter = args.__iter__()
 330         else:
 331                 value_iter = iter(sys.stdin.readline, '')
 332
 333         try:
 334                 for value in value_iter:
 335                         decode_value(reg, value.strip(), options)
 336         except KeyboardInterrupt, e:
 337                 pass
 338
 339         return 0
 340
 341 if __name__ == "__main__":
 342         sys.exit(main())