def Pack(self, offset):
"""Figure out how to pack the entry into the section
Most of the time the entries are not fully specified. There may be
an alignment but no size. In that case we take the size from the
contents of the entry.
If an entry has no hard-coded offset, it will be placed at @offset.
Once this function is complete, both the offset and size of the
entry will be know.
Args:
Current section offset pointer
Returns:
New section offset pointer (after this entry)
"""
self.Detail(
'Packing: offset=%s, size=%s, content_size=%x' %
(to_hex(self.offset), to_hex(self.size), self.contents_size))
if self.offset is None:
if self.offset_unset:
self.Raise('No offset set with offset-unset: should another '
'entry provide this correct offset?')
self.offset = tools.align(offset, self.align)
needed = self.pad_before + self.contents_size + self.pad_after
needed = tools.align(needed, self.align_size)
size = self.size
if not size:
size = needed
new_offset = self.offset + size
aligned_offset = tools.align(new_offset, self.align_end)
if aligned_offset != new_offset:
size = aligned_offset - self.offset
new_offset = aligned_offset
if not self.size:
self.size = size
if self.size < needed:
self.Raise("Entry contents size is %#x (%d) but entry size is "
"%#x (%d)" % (needed, needed, self.size, self.size))
# Check that the alignment is correct. It could be wrong if the
# and offset or size values were provided (i.e. not calculated), but
# conflict with the provided alignment values
if self.size != tools.align(self.size, self.align_size):
self.Raise(
"Size %#x (%d) does not match align-size %#x (%d)" %
(self.size, self.size, self.align_size, self.align_size))
if self.offset != tools.align(self.offset, self.align):
self.Raise("Offset %#x (%d) does not match align %#x (%d)" %
(self.offset, self.offset, self.align, self.align))
self.Detail(
' - packed: offset=%#x, size=%#x, content_size=%#x, next_offset=%x'
% (self.offset, self.size, self.contents_size, new_offset))
return new_offset
def get_data(self):
"""Obtain the full contents of the FIP
Thhis builds the FIP with headers and all required FIP entries.
Returns:
bytes: data resulting from building the FIP
"""
buf = io.BytesIO()
hdr = struct.pack(HEADER_FORMAT, HEADER_MAGIC, HEADER_SERIAL,
self._flags)
buf.write(hdr)
# Calculate the position fo the first entry
offset = len(hdr)
offset += len(self._fip_entries) * ENTRY_SIZE
offset += ENTRY_SIZE # terminating entry
for fent in self._fip_entries:
offset = tools.align(offset, self._align)
fent.offset = offset
offset += fent.size
# Write out the TOC
for fent in self._fip_entries:
hdr = struct.pack(ENTRY_FORMAT, fent.uuid, fent.offset, fent.size,
fent.flags)
buf.write(hdr)
# Write out the entries
for fent in self._fip_entries:
buf.seek(fent.offset)
buf.write(fent.data)
return buf.getvalue()
def CheckSize(self):
contents_size = len(self.data)
size = self.size
if not size:
data = self.GetPaddedData(self.data)
size = len(data)
size = tools.align(size, self.align_size)
if self.size and contents_size > self.size:
self._Raise(
"contents size %#x (%d) exceeds section size %#x (%d)" %
(contents_size, contents_size, self.size, self.size))
if not self.size:
self.size = size
if self.size != tools.align(self.size, self.align_size):
self._Raise(
"Size %#x (%d) does not match align-size %#x (%d)" %
(self.size, self.size, self.align_size, self.align_size))
return size