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