printables, ParseException, restOfLine
from getopt import getopt, GetoptError
-conf = os.path.join(os.getenv("HOME"), ".bitfields.conf")
+# List of paths to look for configuration files. If a directory is specified,
+# it will be (recursively) scanned for .conf files.
+configs = ["/etc/bitfield.d", "/etc/bitfield",
+ os.path.join(os.getenv("HOME"), ".bitfield.d"),
+ os.path.join(os.getenv("HOME"), ".bitfield.conf")]
class bitfield:
- def __init__(self, start_bit, end_bit, name):
- self.start_bit = start_bit
- self.end_bit = end_bit
+ def __init__(self, bits, name):
+ self.bits = bits
self.name = name
self.values = {}
- def start_bit(self):
- return self.start_bit
-
- def end_bit(self):
- return self.end_bit
-
def width(self):
- return 1 + self.end_bit - self.start_bit
+ return len(self.bits)
def add_value(self, value, description):
self.values[int(value)] = description
def mask(self, reg_width, value):
- shift = (reg_width - 1) - self.end_bit
- return (((2 ** self.width() - 1) << (shift))
- & value) >> shift
+ ret = 0
+ out_len = len(self.bits)
+ for out_bit in range(0, out_len):
+ in_bit = self.bits[out_bit]
+ # shift this bit down to the LSB (and mask the rest)
+ i = (value >> (reg_width - in_bit - 1)) & 1
+ # shift back to the output position in the field
+ i <<= out_len - out_bit - 1
+ ret |= i
+ return ret
def value(self, value):
if value in self.values:
return self.values[value]
return None
- def __str__(self):
- return "[%2d:%-2d] %s 0x%x" % (int(self.start_bit),
- int(self.end_bit), self.name, self.mask())
+ @staticmethod
+ def mask_and_shift_to_bits(width, mask, shift):
+ bits = []
+ val = mask << shift
+ for i in range(0, width):
+ if mask & (1 << i):
+ bits.append(width - i - 1 - shift)
+ return bits
@staticmethod
- def parse_bitfield(line):
+ def parse_bitfield(line, reg):
a = line.split(None, 1)
if len(a) != 2:
return None
(range_str, name) = a
- range = (None,None)
- if range_str.find(':') != -1:
- r = range_str.split(":")
- range = (int(r[0]),int(r[1]))
- else:
- range = (int(range_str),int(range_str))
+ bits = []
+ for s in range_str.split(','):
+ if ':' in s:
+ (start, end) = map( \
+ lambda s: reg.bit_number(int(s)),
+ s.split(':'))
+ start = reg.bit_number(int(start))
+ end = reg.bit_number(int(end))
+ bits.extend(range(start, end + 1, 1))
+ elif '<<' in s:
+ (mask, shift) = map(lambda s: int(s.strip()),
+ s.split('<<'))
+ bits.extend(bitfield.mask_and_shift_to_bits( \
+ reg.width, mask, shift))
+ else:
+ bits.append(reg.bit_number(int(s)))
+
+ return bitfield(bits, name)
+
- return bitfield(range[0], range[1], name)
@staticmethod
def parse_value(line):
return a
class register:
- def __init__(self, name, width):
- self.name = name
- self.width = width
+ bit_0_is_msb = 0
+ bit_0_is_lsb = 1
+
+ def __init__(self, id):
+ self.id = id
self.fields = []
+ # set defaults
+ self.name = None
+ self.bit_order = self.bit_0_is_msb
+ self.width = 64
- def add_field(self, field,):
+ def add_field(self, field):
self.fields.append(field)
- def decode(self, value):
+ def decode(self, value, ignore_zero):
field_width = (self.width + 3) / 4
name_width = max(map(lambda f: len(f.name), self.fields))
+
str = "0x%0*lx [%d]\n" % (field_width, value, value)
+
for field in self.fields:
v = field.mask(self.width, value);
+ if ignore_zero and v == 0:
+ continue
desc = field.value(v)
if desc is not None:
- str += "%*s: 0x%s [%s]\n" \
+ str += "%*s: 0x%x [%s]\n" \
% (name_width, field.name, v, desc)
else:
str += "%*s: 0x%x\n" \
% (name_width, field.name, v)
return str
- def __str__(self):
- str = self.name + "\n"
- for f in self.fields:
- str += "\t%s\n" % f
- return str
+ def bit_number(self, number):
+ if self.bit_order == self.bit_0_is_lsb:
+ number = self.width - 1 - number
+ return number
def list_regs(regs):
for (id, r) in regs.iteritems():
self.file = file
self.message = message
-def parse_config(file):
- lbrack = Literal("[").suppress()
- rbrack = Literal("]").suppress()
- colon = Literal(":").suppress()
- semi = Literal(";")
-
- comment = semi + Optional( restOfLine )
-
- nonrbrack = "".join( [ c for c in printables if c != "]" ] ) + " \t"
- nonequals = "".join( [ c for c in printables if c != ":" ] ) + " \t"
-
- sectionDef = lbrack + Word( nonrbrack ) + rbrack
- keyDef = ~lbrack + Word( nonequals ) + colon + restOfLine
-
- bnf = Dict(ZeroOrMore(Group(sectionDef + ZeroOrMore(Group(keyDef)))))
- bnf.ignore(comment)
-
+def parse_config(bnf, regs, file):
f = open(file)
- tokens = bnf.parseString("".join(f.readlines()))
+ tokens = bnf.parseString(f.read())
- regs = {}
+ order_map = {'bit-0-is-lsb': register.bit_0_is_lsb,
+ 'bit-0-is-msb': register.bit_0_is_msb,
+ 'ibm': register.bit_0_is_msb,
+ 'default': register.bit_0_is_msb}
for tok in tokens:
ts = tok.asList()
id = ts.pop(0)
- # default to 64 bit registers
- width = 64
- name = None
+ if regs.has_key(id):
+ raise ConfigurationError(file,
+ "Register %s is already defined" % id)
+
+ reg = register(id)
+
+ alias_id = None
fields = []
for t in ts:
if t[0] == 'name':
name = t[1]
- name = name.strip()
+ reg.name = name.strip()
elif t[0] == 'width':
- width = int(t[1])
+ reg.width = int(t[1])
elif t[0] == 'field':
- f = bitfield.parse_bitfield(t[1])
+ f = bitfield.parse_bitfield(t[1], reg)
if f is None:
raise ConfigurationError(file,
"Invalid field in %s" % id)
fields.append(f)
elif t[0] == 'value':
- f = fields[-1]
- if f is None:
+ if len(fields) == 0:
raise ConfigurationError(file,
"No field for value in %s" % id)
v = bitfield.parse_value(t[1])
if v is None:
raise ConfigurationError(file,
"Invalid value in %s" % id)
- f.add_value(v[0], v[1])
- if name is None or name == '':
+ fields[-1].add_value(v[0], v[1])
+ elif t[0] == 'order':
+ if len(fields) != 0:
+ raise ConfigurationError(file,
+ ("bit order defined after " \
+ + "fields in %s") % id)
+
+ order_str = t[1].strip().lower()
+ order_str = order_str.replace(' ', '-')
+
+ if order_str not in order_map.keys():
+ raise ConfigurationError(file,
+ "Invalid bit order %s in %s" % \
+ (order_str, id))
+ reg.bit_order = order_map[order_str]
+
+ elif t[0] == 'alias':
+ alias_id = t[1].strip()
+
+ if alias_id is not None:
+ if reg.name is not None or fields != []:
+ raise ConfigurationError(file, ("Definiton " \
+ + "for %s is an alias, but has other " \
+ + "attributes") % id)
+
+ if not regs.has_key(alias_id):
+ raise ConfigurationError(file, "Aliasing "
+ "non-existent register %s (from %s)" \
+ % (alias_id, id))
+
+ reg = regs[alias_id]
+ continue
+
+ if reg.name is None or reg.name == '':
raise ConfigurationError(file,
- "No name for entry %s" %id)
+ "No name for entry %s" % id)
if len(fields) == 0:
raise ConfigurationError(file,
"Register %s has no fields" % id)
- r = register(name, width)
for f in fields:
- r.add_field(f)
+ reg.add_field(f)
- regs[id] = r
+ regs[id] = reg
- return regs
+def parse_config_dir(data, dir, fnames):
+ (bnf, regs) = data
+ for fname in fnames:
+ full_fname = os.path.join(dir, fname)
+
+ if os.path.isdir(full_fname):
+ continue
+ if fname.endswith('.conf'):
+ parse_config(bnf, regs, full_fname)
+
+def parse_all_configs(configs):
+ regs = {}
+
+ # set up the bnf to be used for each file
+ lbrack = Literal("[").suppress()
+ rbrack = Literal("]").suppress()
+ colon = Literal(":").suppress()
+ semi = Literal(";")
+
+ comment = semi + Optional(restOfLine)
+
+ nonrbrack = "".join([c for c in printables if c != "]"]) + " \t"
+ noncolon = "".join([c for c in printables if c != ":"]) + " \t"
+
+ sectionDef = lbrack + Word(nonrbrack) + rbrack
+ keyDef = ~lbrack + Word(noncolon) + colon + restOfLine
+
+ bnf = Dict(ZeroOrMore(Group(sectionDef + ZeroOrMore(Group(keyDef)))))
+ bnf.ignore(comment)
+
+ # bundle into a single var that can be passed to os.path.walk
+ conf_data = (bnf, regs)
+
+ for conf in configs:
+ if not os.path.exists(conf):
+ continue
+ if os.path.isdir(conf):
+ os.path.walk(conf, parse_config_dir, conf_data)
+ else:
+ parse_config(bnf, regs, conf)
+ return regs
def usage(prog):
- print "Usage: %s <-l> | <-s pattern> | register [value...]" % prog
+ print "Usage: %s <-l> | <-s pattern> | [-n] register [value...]" % prog
+
+def decode_value(reg, value, options):
+ try:
+ i = long(value, 0)
+ except ValueError, e:
+ print "error: invalid value '%s'" % value
+ return
+
+ if i > ((1 << reg.width) - 1):
+ print ("error: value '%s' is too large " + \
+ "for %d-bit register '%s'") % (value, reg.width, reg.id)
+ return
+
+ print reg.decode(i, options['non-zero'])
+
def main():
try:
- (opts, args) = getopt(sys.argv[1:], "hls:", \
- ["help", "list", "search="])
+ (opts, args) = getopt(sys.argv[1:], "hlns:", \
+ ["help", "list", "non-zero", "search="])
except GetoptError:
usage(sys.argv[0])
return 1
try:
- regs = parse_config(conf)
-
+ regs = parse_all_configs(configs)
except ConfigurationError, e:
print "Error parsing configuration file %s:\n\t%s" % \
(e.file, e.message)
return 1
+ if regs == {}:
+ print "No configuration available"
+ return 1
+
+ options = {}
+ options['non-zero'] = False
+
for o, a in opts:
if o in ("-h", "--help"):
usage(sys.argv[0])
list_regs(search_regs(regs, a))
return
+ if o in ("-n", "--non-zero"):
+ options['non-zero'] = True
if not args:
usage(sys.argv[0])
return 1
- a = args.pop(0)
- if not regs.has_key(a):
- print "No such register '%s'. Valid regs are:" % a
- list_regs(regs)
+ reg_id = args.pop(0)
+ if not regs.has_key(reg_id):
+ print "No such register '%s'" % reg_id
return 1
- r = regs[a]
- print "decoding as %s" % r.name
+ reg = regs[reg_id]
+ print "decoding as %s" % reg.name
if args:
- values = args
+ value_iter = args.__iter__()
else:
- try:
- values = sys.stdin.readlines()
- except KeyboardInterrupt, e:
- return
+ value_iter = iter(sys.stdin.readline, '')
- for value in values:
- i = long(value.strip(), 0)
- print r.decode(i)
+ try:
+ for value in value_iter:
+ decode_value(reg, value.strip(), options)
+ except KeyboardInterrupt, e:
+ pass
return 0