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