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