def __init__(self, buf, endianness='<'):
"""Parse a bytestring buf containing a BootInfo struct.
Endianness may be provided using Python's struct module notation,
but should always be little-endian for all current Mikroe kits,
at least from what I know."""
def unpack(fmt, buf):
return struct.unpack(endianness + fmt, buf)
# Get sizeof struct and truncate it
bSize = bord(buf[0])
buf = buf[:bSize]
pos = 1
while pos < len(buf):
# Skip initial field padding
pad = 0
while pos < len(buf) and bord(buf[pos]) == 0:
pos += 1
pad += 1
if pos >= len(buf): break
# Parse field type
field_type = bord(buf[pos])
if field_type not in _field:
logger.error('Field %d not recognized -- aborting parsing' % field_type)
break
name, num_bytes, enum_map = _field[field_type]
pad_bytes = min(num_bytes, 4)
# Check for any alignment override
if 'McuType' in self and name in _fieldalign_override:
pad_bytes = _fieldalign_override[name].get(self['McuType'], pad_bytes)
# Sanity check the detected initial padding
if pad >= pad_bytes or (num_bytes <= 4 and pos % pad_bytes != 0):
logger.warn('Initial padding of %d inadequate in field "%s" (%d)' % (pad, name, field_type))
# Go to data (skip the internal padding)
pos += 1
if num_bytes <= 4:
pad = (pad_bytes - pos % pad_bytes) % pad_bytes
pos += pad
# Read the value
fmt = {1: 'B', 2: 'H', 4: 'L'}
value = buf[pos:pos+num_bytes]
if num_bytes in fmt:
value, = unpack(fmt[num_bytes], value)
pos += num_bytes
# Fill the field
if enum_map:
if value in enum_map:
value = enum_map[value]
else:
logger.warn('Field "%s" (%d) contains value %d not mapped in its enum' % (name, field_type, value))
if name in self:
logger.warn('Field "%s" (%d) duplicated -- discarding old value: %s' % (name, field_type, repr(fields[name])))
self[name] = value
def load(f, devkit):
"""Load a Intel HEX File from a file object into a devkit.
The devkit must implement a write(address,data) method."""
lineno = 0
base_addr = 0
for line in f.xreadlines():
lineno += 1
line = line.strip()
if line == '':
continue
if bord(line[0]) != ord(':'):
raise IOError('line %d: malformed' % lineno)
line = unhexlify(line[1:])
byte_count, address, record_type = struct.unpack('>BHB', line[:4])
correct_len = byte_count + 5
if len(line) != correct_len:
logger.warn('line %d: should have %d bytes -- truncating' % (lineno, correct_len))
line = line[:correct_len]
if sum(map(bord,line)) & 0xFF != 0:
raise IOError('line %d: incorrect checksum' % lineno)
data = line[4:-1]
if record_type == 0x00: # data record
devkit.write(base_addr + address, data)
elif record_type == 0x01: # end of file record
break
elif record_type == 0x04: # extended linear address record
if byte_count != 2:
raise IOError('line %d: extended linear address record must have 2 bytes of data' % lineno)
base_addr, = struct.unpack('>H', data)
base_addr <<= 16
elif record_type == 0x02: # extended segment address record
base_addr, = struct.unpack('>H', data)
base_addr <<= 4
elif record_type not in [0x03, 0x05]: # used for the initial PC (ignored)
raise IOError('line %d: unsupported record type %d' % (lineno, record_type))
def write(self, addr, data):
if addr >= self.config_data_addr:
return
assert(len(data) % 4 == 0)
newd = []
# discard padding bytes (at every fourth byte)
for i in xrange(0, len(data), 4):
newd += list(data[i:i+3])
padbyte = bord(data[i+3])
if padbyte != 0:
logger.warning('padding byte at addr 0x%x (%02X) is not null' %
(addr+i+3, padbyte))
# write the new data array
self._write_phy(self._hex_addr_to_phy(addr), bytearray(newd))
def load(f, devkit):
"""Load a Intel HEX File from a file object into a devkit.
The devkit must implement a write(address,data) method."""
lineno = 0
base_addr = 0
for line in f.xreadlines():
lineno += 1
line = line.strip()
if line == '':
continue
if bord(line[0]) != ord(':'):
raise IOError('line %d: malformed' % lineno)
line = unhexlify(line[1:])
byte_count, address, record_type = struct.unpack('>BHB', line[:4])
correct_len = byte_count + 5
if len(line) != correct_len:
logger.warn('line %d: should have %d bytes -- truncating' %
(lineno, correct_len))
line = line[:correct_len]
if sum(map(bord, line)) & 0xFF != 0:
raise IOError('line %d: incorrect checksum' % lineno)
data = line[4:-1]
if record_type == 0x00: # data record
devkit.write(base_addr + address, data)
elif record_type == 0x01: # end of file record
break
elif record_type == 0x04: # extended linear address record
if byte_count != 2:
raise IOError(
'line %d: extended linear address record must have 2 bytes of data'
% lineno)
base_addr, = struct.unpack('>H', data)
base_addr <<= 16
elif record_type == 0x02: # extended segment address record
base_addr, = struct.unpack('>H', data)
base_addr <<= 4
elif record_type not in [0x03,
0x05]: # used for the initial PC (ignored)
raise IOError('line %d: unsupported record type %d' %
(lineno, record_type))
