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