src/bsv/interface_decl.py

   1 import os.path
   2
   3 try:
   4     from UserDict import UserDict
   5 except ImportError:
   6     from collections import UserDict
   7
   8 from bsv.wire_def import generic_io  # special case
   9 from bsv.wire_def import muxwire  # special case
  10 from ifacebase import InterfacesBase
  11 from bsv.peripheral_gen import PeripheralIface
  12 from bsv.peripheral_gen import PeripheralInterfaces
  13
  14
  15 class Pin(object):
  16     """ pin interface declaration.
  17         * name is the name of the pin
  18         * ready, enabled and io all create a (* .... *) prefix
  19         * action changes it to an "in" if true
  20     """
  21
  22     def __init__(self, name,
  23                  name_=None,
  24                  idx=None,
  25                  ready=True,
  26                  enabled=True,
  27                  io=False,
  28                  action=False,
  29                  bitspec=None,
  30                  outenmode=False):
  31         self.name = name
  32         self.name_ = name_
  33         self.idx = idx
  34         self.ready = ready
  35         self.enabled = enabled
  36         self.io = io
  37         self.action = action
  38         self.bitspec = bitspec if bitspec else 'Bit#(1)'
  39         self.outenmode = outenmode
  40
  41     # bsv will look like this (method declaration):
  42     """
  43     (*always_ready,always_enabled*) method Bit#(1) io0_cell_outen;
  44     (*always_ready,always_enabled,result="io"*) method
  45                        Action io0_inputval (Bit#(1) in);
  46     """
  47
  48     def ifacepfmt(self, fmtfn):
  49         res = '          '
  50         status = []
  51         res += "interface "
  52         name = fmtfn(self.name_)
  53         if self.action:
  54             res += "Put"
  55         else:
  56             res += "Get"
  57         res += "#(%s) %s;" % (self.bitspec, name)
  58         return res
  59
  60     def ifacefmt(self, fmtfn):
  61         res = '    '
  62         status = []
  63         if self.ready:
  64             status.append('always_ready')
  65         if self.enabled:
  66             status.append('always_enabled')
  67         if self.io:
  68             status.append('result="io"')
  69         if status:
  70             res += '(*'
  71             res += ','.join(status)
  72             res += '*)'
  73         res += " method "
  74         if self.io:
  75             res += "\n                      "
  76         name = fmtfn(self.name)
  77         if self.action:
  78             res += " Action "
  79             res += name
  80             res += ' (%s in)' % self.bitspec
  81         else:
  82             res += " %s " % self.bitspec
  83             res += name
  84         res += ";"
  85         return res
  86
  87     def ifacedef(self, fmtoutfn, fmtinfn, fmtdecfn):
  88         res = '      method '
  89         if self.action:
  90             fmtname = fmtinfn(self.name)
  91             res += "Action  "
  92             res += fmtdecfn(self.name)
  93             res += '(%s in);\n' % self.bitspec
  94             res += '         %s<=in;\n' % fmtname
  95             res += '      endmethod'
  96         else:
  97             fmtname = fmtoutfn(self.name)
  98             res += "%s=%s;" % (self.name, fmtname)
  99         return res
 100     # sample bsv method definition :
 101     """
 102     method Action  cell0_mux(Bit#(2) in);
 103         wrcell0_mux<=in;
 104     endmethod
 105     """
 106
 107     # sample bsv wire (wire definiton):
 108     """
 109     Wire#(Bit#(2)) wrcell0_mux<-mkDWire(0);
 110     """
 111
 112     def wirefmt(self, fmtoutfn, fmtinfn, fmtdecfn):
 113         res = '      Wire#(%s) ' % self.bitspec
 114         if self.action:
 115             res += '%s' % fmtinfn(self.name)
 116         else:
 117             res += '%s' % fmtoutfn(self.name)
 118         res += "<-mkDWire(0);"
 119         return res
 120
 121     def ifacedef2(self, fmtoutfn, fmtinfn, fmtdecfn):
 122         if self.action:
 123             fmtname = fmtinfn(self.name)
 124             res = "            interface %s = interface Put\n" % self.name_
 125             res += '              method '
 126             res += "Action put"
 127             #res += fmtdecfn(self.name)
 128             res += '(%s in);\n' % self.bitspec
 129             res += '                %s<=in;\n' % fmtname
 130             res += '              endmethod\n'
 131             res += '            endinterface;'
 132         else:
 133             fmtname = fmtoutfn(self.name)
 134             res = "            interface %s = interface Get\n" % self.name_
 135             res += '              method ActionValue#'
 136             res += '(%s) get;\n' % self.bitspec
 137             res += "                return %s;\n" % (fmtname)
 138             res += '              endmethod\n'
 139             res += '            endinterface;'
 140         return res
 141
 142     def ifacedef3(self, idx, fmtoutfn, fmtinfn, fmtdecfn):
 143         if self.action:
 144             fmtname = fmtinfn(self.name)
 145             if self.name.endswith('outen'):
 146                 name = "tputen"
 147             else:
 148                 name = "tput"
 149             res = "                   %s <= in[%d];" % (fmtname, idx)
 150         else:
 151             fmtname = fmtoutfn(self.name)
 152             res = "                   tget[%d] = %s;" % (idx, fmtname)
 153             name = 'tget'
 154         return (name, res)
 155
 156
 157 class Interface(PeripheralIface):
 158     """ create an interface from a list of pinspecs.
 159         each pinspec is a dictionary, see Pin class arguments
 160         single indicates that there is only one of these, and
 161         so the name must *not* be extended numerically (see pname)
 162     """
 163     # sample interface object:
 164     """
 165     twiinterface_decl = Interface('twi',
 166                                   [{'name': 'sda', 'outen': True},
 167                                    {'name': 'scl', 'outen': True},
 168                                    ])
 169     """
 170
 171     def __init__(self, ifacename, pinspecs, ganged=None, single=False):
 172         PeripheralIface.__init__(self, ifacename)
 173         self.ifacename = ifacename
 174         self.ganged = ganged or {}
 175         self.pins = []  # a list of instances of class Pin
 176         self.pinspecs = pinspecs  # a list of dictionary
 177         self.single = single
 178
 179         for idx, p in enumerate(pinspecs):
 180             _p = {}
 181             _p.update(p)
 182             if 'type' in _p:
 183                 del _p['type']
 184             if p.get('outen') is True:  # special case, generate 3 pins
 185                 del _p['outen']
 186                 for psuffix in ['out', 'outen', 'in']:
 187                     # changing the name (like sda) to (twi_sda_out)
 188                     _p['name_'] = "%s_%s" % (p['name'], psuffix)
 189                     _p['name'] = "%s_%s" % (self.pname(p['name']), psuffix)
 190                     _p['action'] = psuffix != 'in'
 191                     _p['idx'] = idx
 192                     self.pins.append(Pin(**_p))
 193                     # will look like {'name': 'twi_sda_out', 'action': True}
 194                     # {'name': 'twi_sda_outen', 'action': True}
 195                     #{'name': 'twi_sda_in', 'action': False}
 196                     # NOTice - outen key is removed
 197             else:
 198                 name = p['name']
 199                 if name.isdigit():  # HACK!  deals with EINT case
 200                     name = self.pname(name)
 201                 _p['name_'] = name
 202                 _p['idx'] = idx
 203                 _p['name'] = self.pname(p['name'])
 204                 self.pins.append(Pin(**_p))
 205
 206     # sample interface object:
 207     """
 208         uartinterface_decl = Interface('uart',
 209                                    [{'name': 'rx'},
 210                                     {'name': 'tx', 'action': True},
 211                                     ])
 212     """
 213     """
 214     getifacetype is called multiple times in actual_pinmux.py
 215     x = ifaces.getifacetype(temp), where temp is uart_rx, spi_mosi
 216     Purpose is to identify is function : input/output/inout
 217     """
 218
 219     def getifacetype(self, name):
 220         for p in self.pinspecs:
 221             fname = "%s_%s" % (self.ifacename, p['name'])
 222             # print "search", self.ifacename, name, fname
 223             if fname == name:
 224                 if p.get('action'):
 225                     return 'out'
 226                 elif p.get('outen'):
 227                     return 'inout'
 228                 return 'input'
 229         return None
 230
 231     def iname(self):
 232         """ generates the interface spec e.g. flexbus_ale
 233             if there is only one flexbus interface, or
 234             sd{0}_cmd if there are several.  string format
 235             function turns this into sd0_cmd, sd1_cmd as
 236             appropriate.  single mode stops the numerical extension.
 237         """
 238         if self.single:
 239             return self.ifacename
 240         return '%s{0}' % self.ifacename
 241
 242     def pname(self, name):
 243         """ generates the interface spec e.g. flexbus_ale
 244             if there is only one flexbus interface, or
 245             sd{0}_cmd if there are several.  string format
 246             function turns this into sd0_cmd, sd1_cmd as
 247             appropriate.  single mode stops the numerical extension.
 248         """
 249         return "%s_%s" % (self.iname(), name)
 250
 251     def busfmt(self, *args):
 252         """ this function creates a bus "ganging" system based
 253             on input from the {interfacename}.txt file.
 254             only inout pins that are under the control of the
 255             interface may be "ganged" together.
 256         """
 257         if not self.ganged:
 258             return ''  # when self.ganged is None
 259         # print self.ganged
 260         res = []
 261         for (k, pnames) in self.ganged.items():
 262             name = self.pname('%senable' % k).format(*args)
 263             decl = 'Bit#(1) %s = 0;' % name
 264             res.append(decl)
 265             ganged = []
 266             for p in self.pinspecs:
 267                 if p['name'] not in pnames:
 268                     continue
 269                 pname = self.pname(p['name']).format(*args)
 270                 if p.get('outen') is True:
 271                     outname = self.ifacefmtoutfn(pname)
 272                     ganged.append("%s_outen" % outname)  # match wirefmt
 273
 274             gangedfmt = '{%s} = duplicate(%s);'
 275             res.append(gangedfmt % (',\n  '.join(ganged), name))
 276         return '\n'.join(res) + '\n\n'
 277
 278     def wirefmt(self, *args):
 279         res = '\n'.join(map(self.wirefmtpin, self.pins)).format(*args)
 280         res += '\n'
 281         return '\n' + res
 282
 283     def ifacepfmt(self, *args):
 284         res = '\n'.join(map(self.ifacepfmtdecpin, self.pins)).format(*args)
 285         return '\n' + res  # pins is a list
 286
 287     def ifacefmt(self, *args):
 288         res = '\n'.join(map(self.ifacefmtdecpin, self.pins)).format(*args)
 289         return '\n' + res  # pins is a list
 290
 291     def ifacepfmtdecfn(self, name):
 292         return name
 293
 294     def ifacefmtdecfn(self, name):
 295         return name  # like: uart
 296
 297     def ifacefmtdecfn2(self, name):
 298         return name  # like: uart
 299
 300     def ifacefmtdecfn3(self, name):
 301         """ HACK! """
 302         return "%s_outen" % name  # like uart_outen
 303
 304     def ifacefmtoutfn(self, name):
 305         return "wr%s" % name  # like wruart
 306
 307     def ifacefmtinfn(self, name):
 308         return "wr%s" % name
 309
 310     def wirefmtpin(self, pin):
 311         return pin.wirefmt(self.ifacefmtoutfn, self.ifacefmtinfn,
 312                            self.ifacefmtdecfn2)
 313
 314     def ifacepfmtdecpin(self, pin):
 315         return pin.ifacepfmt(self.ifacepfmtdecfn)
 316
 317     def ifacefmtdecpin(self, pin):
 318         return pin.ifacefmt(self.ifacefmtdecfn)
 319
 320     def ifacefmtpin(self, pin):
 321         decfn = self.ifacefmtdecfn2
 322         outfn = self.ifacefmtoutfn
 323         # print pin, pin.outenmode
 324         if pin.outenmode:
 325             decfn = self.ifacefmtdecfn3
 326             outfn = self.ifacefmtoutenfn
 327         return pin.ifacedef(outfn, self.ifacefmtinfn,
 328                             decfn)
 329
 330     def ifacedef2pin(self, pin):
 331         decfn = self.ifacefmtdecfn2
 332         outfn = self.ifacefmtoutfn
 333         # print pin, pin.outenmode
 334         if pin.outenmode:
 335             decfn = self.ifacefmtdecfn3
 336             outfn = self.ifacefmtoutenfn
 337         return pin.ifacedef2(outfn, self.ifacefmtinfn,
 338                              decfn)
 339
 340     def ifacedef(self, *args):
 341         res = '\n'.join(map(self.ifacefmtpin, self.pins))
 342         res = res.format(*args)
 343         return '\n' + res + '\n'
 344
 345     def ifacedef2(self, *args):
 346         res = '\n'.join(map(self.ifacedef2pin, self.pins))
 347         res = res.format(*args)
 348         return '\n' + res + '\n'
 349
 350     def vectorifacedef2(self, pins, count, names, bitfmt, *args):
 351         tput = []
 352         tget = []
 353         tputen = []
 354         # XXX HACK! assume in, out and inout, create set of indices
 355         # that are repeated three times.
 356         plens = []
 357         # ARG even worse hack for LCD *sigh*...
 358         if names[1] is None and names[2] is None:
 359             plens = range(len(pins))
 360         else:
 361             for i in range(0, len(pins), 3):
 362                 plens += [i/3, i/3, i/3]
 363         for (typ, txt) in map(self.ifacedef3pin, plens, pins):
 364             if typ == 'tput':
 365                 tput.append(txt)
 366             elif typ == 'tget':
 367                 tget.append(txt)
 368             elif typ == 'tputen':
 369                 tputen.append(txt)
 370         tput = '\n'.join(tput).format(*args)
 371         tget = '\n'.join(tget).format(*args)
 372         tputen = '\n'.join(tputen).format(*args)
 373         bitfmt = bitfmt.format(count)
 374         template = ["""\
 375               interface {3} = interface Put#({0})
 376                  method Action put({2} in);
 377 {1}
 378                  endmethod
 379                endinterface;
 380 """,
 381 """\
 382                interface {3} = interface Put#({0})
 383                  method Action put({2} in);
 384 {1}
 385                  endmethod
 386                endinterface;
 387 """,
 388 """\
 389                interface {3} = interface Get#({0})
 390                  method ActionValue#({2}) get;
 391                    {2} tget;
 392 {1}
 393                    return tget;
 394                  endmethod
 395                endinterface;
 396 """]
 397         res = ''
 398         tlist = [tput, tputen, tget]
 399         for i, n in enumerate(names):
 400             if n:
 401                 res += template[i].format(count, tlist[i], bitfmt, n)
 402         return '\n' + res + '\n'
 403
 404
 405 class MuxInterface(Interface):
 406
 407     def wirefmt(self, *args):
 408         return muxwire.format(*args)
 409
 410
 411 class IOInterface(Interface):
 412
 413     def ifacefmtoutenfn(self, name):
 414         return "cell{0}_mux_outen"
 415
 416     def ifacefmtoutfn(self, name):
 417         """ for now strip off io{0}_ part """
 418         return "cell{0}_mux_out"
 419
 420     def ifacefmtinfn(self, name):
 421         return "cell{0}_mux_in"
 422
 423     def wirefmt(self, *args):
 424         return generic_io.format(*args)
 425
 426
 427 class InterfaceBus(object):
 428
 429     def __init__(self, namelist, bitspec, filterbus):
 430         self.namelist = namelist
 431         self.bitspec = bitspec
 432         self.fbus = filterbus # filter identifying which are bus pins
 433
 434     def get_nonbuspins(self):
 435         return filter(lambda x: not x.name_.startswith(self.fbus), self.pins)
 436
 437     def get_buspins(self):
 438         return filter(lambda x: x.name_.startswith(self.fbus), self.pins)
 439
 440     def ifacepfmt(self, *args):
 441         pins = self.get_nonbuspins()
 442         res = '\n'.join(map(self.ifacepfmtdecpin, pins)).format(*args)
 443         res = res.format(*args)
 444
 445         pins = self.get_buspins()
 446         plen = self.get_n_iopins(pins)
 447
 448         res += '\n'
 449         template = "          interface {1}#(Bit#({0})) {2};\n"
 450         for i, n in enumerate(self.namelist):
 451             if not n:
 452                 continue
 453             ftype = 'Get' if i == 2 else "Put"
 454             res += template.format(plen, ftype, n)
 455
 456         return "\n" + res
 457
 458     def ifacedef2(self, *args):
 459         pins = self.get_nonbuspins()
 460         res = '\n'.join(map(self.ifacedef2pin, pins))
 461         res = res.format(*args)
 462
 463         pins = self.get_buspins()
 464         plen = self.get_n_iopins(pins)
 465         bitspec = "Bit#({0})".format(plen)
 466         return '\n' + res + self.vectorifacedef2(pins, plen,
 467                                     self.namelist, bitspec, *args) + '\n'
 468
 469     def ifacedef3pin(self, idx, pin):
 470         decfn = self.ifacefmtdecfn2
 471         outfn = self.ifacefmtoutfn
 472         # print pin, pin.outenmode
 473         if pin.outenmode:
 474             decfn = self.ifacefmtdecfn3
 475             outfn = self.ifacefmtoutenfn
 476         return pin.ifacedef3(idx, outfn, self.ifacefmtinfn,
 477                              decfn)
 478
 479
 480 class InterfaceLCD(InterfaceBus, Interface):
 481
 482     def __init__(self, *args):
 483         InterfaceBus.__init__(self, ['data_out', None, None],
 484                               "Bit#({0})", "out")
 485         Interface.__init__(self, *args)
 486
 487     def get_n_iopins(self, pins): # HACK! assume in/out/outen so div by 3
 488         return len(pins)
 489
 490
 491 class InterfaceNSPI(InterfaceBus, Interface):
 492
 493     def __init__(self, *args):
 494         InterfaceBus.__init__(self, ['io_out', 'io_out_en', 'io_in'],
 495                               "Bit#({0})", "io")
 496         Interface.__init__(self, *args)
 497
 498     def get_n_iopins(self, pins): # HACK! assume in/out/outen so div by 3
 499         return len(pins) / 3
 500
 501
 502 class InterfaceEINT(Interface):
 503     """ uses old-style (non-get/put) for now
 504     """
 505     def ifacepfmt(self, *args):
 506         res = '\n'.join(map(self.ifacefmtdecpin, self.pins)).format(*args)
 507         return '\n' + res  # pins is a list
 508
 509     def ifacedef2(self, *args):
 510         return self.ifacedef(*args)
 511
 512
 513
 514 class InterfaceGPIO(Interface):
 515
 516     def ifacepfmt(self, *args):
 517         return """
 518           interface Put#(Vector#({0}, Bit#(1))) out;
 519           interface Put#(Vector#({0}, Bit#(1))) out_en;
 520           interface Get#(Vector#({0}, Bit#(1))) in;
 521 """.format(len(self.pinspecs))
 522
 523     def ifacedef2(self, *args):
 524         return self.vectorifacedef2(self.pins, len(self.pinspecs),
 525                         ['out', 'out_en', 'in'],
 526                                     "Vector#({0},Bit#(1))", *args)
 527
 528     def ifacedef3pin(self, idx, pin):
 529         decfn = self.ifacefmtdecfn2
 530         outfn = self.ifacefmtoutfn
 531         # print pin, pin.outenmode
 532         if pin.outenmode:
 533             decfn = self.ifacefmtdecfn3
 534             outfn = self.ifacefmtoutenfn
 535         return pin.ifacedef3(idx, outfn, self.ifacefmtinfn,
 536                              decfn)
 537
 538
 539 class Interfaces(InterfacesBase, PeripheralInterfaces):
 540     """ contains a list of interface definitions
 541     """
 542
 543     def __init__(self, pth=None):
 544         InterfacesBase.__init__(self, Interface, pth,
 545                                 {'gpio': InterfaceGPIO,
 546                                  'spi': InterfaceNSPI,
 547                                  'lcd': InterfaceLCD,
 548                                  'qspi': InterfaceNSPI,
 549                                  'eint': InterfaceEINT})
 550         PeripheralInterfaces.__init__(self)
 551
 552     def ifacedef(self, f, *args):
 553         for (name, count) in self.ifacecount:
 554             for i in range(count):
 555                 f.write(self.data[name].ifacedef(i))
 556
 557     def ifacedef2(self, f, *args):
 558         c = "        interface {0} = interface PeripheralSide{1}"
 559         for (name, count) in self.ifacecount:
 560             for i in range(count):
 561                 iname = self.data[name].iname().format(i)
 562                 f.write(c.format(iname, name.upper()))
 563                 f.write(self.data[name].ifacedef2(i))
 564                 f.write("        endinterface;\n\n")
 565
 566     def busfmt(self, f, *args):
 567         f.write("import BUtils::*;\n\n")
 568         for (name, count) in self.ifacecount:
 569             for i in range(count):
 570                 bf = self.data[name].busfmt(i)
 571                 f.write(bf)
 572
 573     def ifacepfmt(self, f, *args):
 574         comment = '''
 575       // interface declaration between {0} and pinmux
 576       (*always_ready,always_enabled*)
 577       interface PeripheralSide{0};'''
 578         for (name, count) in self.ifacecount:
 579             f.write(comment.format(name.upper()))
 580             f.write(self.data[name].ifacepfmt(0))
 581             f.write("\n      endinterface\n")
 582
 583     def ifacefmt(self, f, *args):
 584         comment = '''
 585           // interface declaration between %s-{0} and pinmux'''
 586         for (name, count) in self.ifacecount:
 587             for i in range(count):
 588                 c = comment % name.upper()
 589                 f.write(c.format(i))
 590                 f.write(self.data[name].ifacefmt(i))
 591
 592     def ifacefmt2(self, f, *args):
 593         comment = '''
 594             interface PeripheralSide{0} {1};'''
 595         for (name, count) in self.ifacecount:
 596             for i in range(count):
 597                 iname = self.data[name].iname().format(i)
 598                 f.write(comment.format(name.upper(), iname))
 599
 600     def wirefmt(self, f, *args):
 601         comment = '\n      // following wires capture signals ' \
 602                   'to IO CELL if %s-{0} is\n' \
 603                   '      // allotted to it'
 604         for (name, count) in self.ifacecount:
 605             for i in range(count):
 606                 c = comment % name
 607                 f.write(c.format(i))
 608                 f.write(self.data[name].wirefmt(i))
 609
 610
 611 # ========= Interface declarations ================ #
 612
 613 mux_interface = MuxInterface('cell',
 614                              [{'name': 'mux', 'ready': False, 'enabled': False,
 615                                'bitspec': '{1}', 'action': True}])
 616
 617 io_interface = IOInterface(
 618     'io',
 619     [{'name': 'cell_out', 'enabled': True, },
 620      {'name': 'cell_outen', 'enabled': True, 'outenmode': True, },
 621      {'name': 'cell_in', 'action': True, 'io': True}, ])
 622
 623 # == Peripheral Interface definitions == #
 624 # these are the interface of the peripherals to the pin mux
 625 # Outputs from the peripherals will be inputs to the pinmux
 626 # module. Hence the change in direction for most pins
 627
 628 # ======================================= #
 629
 630 # basic test
 631 if __name__ == '__main__':
 632
 633     uartinterface_decl = Interface('uart',
 634                                    [{'name': 'rx'},
 635                                     {'name': 'tx', 'action': True},
 636                                     ])
 637
 638     twiinterface_decl = Interface('twi',
 639                                   [{'name': 'sda', 'outen': True},
 640                                    {'name': 'scl', 'outen': True},
 641                                    ])
 642
 643     def _pinmunge(p, sep, repl, dedupe=True):
 644         """ munges the text so it's easier to compare.
 645             splits by separator, strips out blanks, re-joins.
 646         """
 647         p = p.strip()
 648         p = p.split(sep)
 649         if dedupe:
 650             p = filter(lambda x: x, p)  # filter out blanks
 651         return repl.join(p)
 652
 653     def pinmunge(p):
 654         """ munges the text so it's easier to compare.
 655         """
 656         # first join lines by semicolons, strip out returns
 657         p = p.split(";")
 658         p = map(lambda x: x.replace('\n', ''), p)
 659         p = '\n'.join(p)
 660         # now split first by brackets, then spaces (deduping on spaces)
 661         p = _pinmunge(p, "(", " ( ", False)
 662         p = _pinmunge(p, ")", " ) ", False)
 663         p = _pinmunge(p, " ", " ")
 664         return p
 665
 666     def zipcmp(l1, l2):
 667         l1 = l1.split("\n")
 668         l2 = l2.split("\n")
 669         for p1, p2 in zip(l1, l2):
 670             print (repr(p1))
 671             print (repr(p2))
 672             print ()
 673             assert p1 == p2
 674
 675     ifaces = Interfaces()
 676
 677     ifaceuart = ifaces['uart']
 678     print (ifaceuart.ifacedef(0))
 679     print (uartinterface_decl.ifacedef(0))
 680     assert ifaceuart.ifacedef(0) == uartinterface_decl.ifacedef(0)
 681
 682     ifacetwi = ifaces['twi']
 683     print (ifacetwi.ifacedef(0))
 684     print (twiinterface_decl.ifacedef(0))
 685     assert ifacetwi.ifacedef(0) == twiinterface_decl.ifacedef(0)