diff options
Diffstat (limited to 'tools/binman/cbfs_util.py')
| -rw-r--r-- | tools/binman/cbfs_util.py | 125 |
1 files changed, 102 insertions, 23 deletions
diff --git a/tools/binman/cbfs_util.py b/tools/binman/cbfs_util.py index ec4a2e5a8c6..1cdbcb2339e 100644 --- a/tools/binman/cbfs_util.py +++ b/tools/binman/cbfs_util.py @@ -12,7 +12,7 @@ it is necessary to rely on the C structures and source code (mostly cbfstool) to fully understand it. Currently supported: raw and stage types with compression, padding empty areas - with empty files + with empty files, fixed-offset files """ from __future__ import print_function @@ -190,6 +190,8 @@ class CbfsFile(object): Properties: name: Name of file offset: Offset of file data from start of file header + cbfs_offset: Offset of file data in bytes from start of CBFS, or None to + place this file anyway data: Contents of file, uncompressed data_len: Length of (possibly compressed) data in bytes ftype: File type (TYPE_...) @@ -203,9 +205,10 @@ class CbfsFile(object): contents (used for empty files) size: Size of the file in bytes (used for empty files) """ - def __init__(self, name, ftype, data, compress=COMPRESS_NONE): + def __init__(self, name, ftype, data, cbfs_offset, compress=COMPRESS_NONE): self.name = name self.offset = None + self.cbfs_offset = cbfs_offset self.data = data self.ftype = ftype self.compress = compress @@ -231,7 +234,7 @@ class CbfsFile(object): self.data_len = len(indata) @classmethod - def stage(cls, base_address, name, data): + def stage(cls, base_address, name, data, cbfs_offset): """Create a new stage file Args: @@ -239,28 +242,32 @@ class CbfsFile(object): name: String file name to put in CBFS (does not need to correspond to the name that the file originally came from) data: Contents of file + cbfs_offset: Offset of file data in bytes from start of CBFS, or + None to place this file anyway Returns: CbfsFile object containing the file information """ - cfile = CbfsFile(name, TYPE_STAGE, data) + cfile = CbfsFile(name, TYPE_STAGE, data, cbfs_offset) cfile.base_address = base_address return cfile @classmethod - def raw(cls, name, data, compress): + def raw(cls, name, data, cbfs_offset, compress): """Create a new raw file Args: name: String file name to put in CBFS (does not need to correspond to the name that the file originally came from) data: Contents of file + cbfs_offset: Offset of file data in bytes from start of CBFS, or + None to place this file anyway compress: Compression algorithm to use (COMPRESS_...) Returns: CbfsFile object containing the file information """ - return CbfsFile(name, TYPE_RAW, data, compress) + return CbfsFile(name, TYPE_RAW, data, cbfs_offset, compress) @classmethod def empty(cls, space_to_use, erase_byte): @@ -275,12 +282,44 @@ class CbfsFile(object): Returns: CbfsFile object containing the file information """ - cfile = CbfsFile('', TYPE_EMPTY, b'') + cfile = CbfsFile('', TYPE_EMPTY, b'', None) cfile.size = space_to_use - FILE_HEADER_LEN - FILENAME_ALIGN cfile.erase_byte = erase_byte return cfile - def get_data(self): + def calc_start_offset(self): + """Check if this file needs to start at a particular offset in CBFS + + Returns: + None if the file can be placed anywhere, or + the largest offset where the file could start (integer) + """ + if self.cbfs_offset is None: + return None + return self.cbfs_offset - self.get_header_len() + + def get_header_len(self): + """Get the length of headers required for a file + + This is the minimum length required before the actual data for this file + could start. It might start later if there is padding. + + Returns: + Total length of all non-data fields, in bytes + """ + name = _pack_string(self.name) + hdr_len = len(name) + FILE_HEADER_LEN + if self.ftype == TYPE_STAGE: + pass + elif self.ftype == TYPE_RAW: + hdr_len += ATTR_COMPRESSION_LEN + elif self.ftype == TYPE_EMPTY: + pass + else: + raise ValueError('Unknown file type %#x\n' % self.ftype) + return hdr_len + + def get_data(self, offset=None, pad_byte=None): """Obtain the contents of the file, in CBFS format Returns: @@ -292,6 +331,7 @@ class CbfsFile(object): attr_pos = 0 content = b'' attr = b'' + pad = b'' data = self.data if self.ftype == TYPE_STAGE: elf_data = elf.DecodeElf(data, self.base_address) @@ -315,10 +355,33 @@ class CbfsFile(object): if attr: attr_pos = hdr_len hdr_len += len(attr) - hdr = struct.pack(FILE_HEADER_FORMAT, FILE_MAGIC, - len(content) + len(data), + if self.cbfs_offset is not None: + pad_len = self.cbfs_offset - offset - hdr_len + if pad_len < 0: # pragma: no cover + # Test coverage of this is not available since this should never + # happen. It indicates that get_header_len() provided an + # incorrect value (too small) so that we decided that we could + # put this file at the requested place, but in fact a previous + # file extends far enough into the CBFS that this is not + # possible. + raise ValueError("Internal error: CBFS file '%s': Requested offset %#x but current output position is %#x" % + (self.name, self.cbfs_offset, offset)) + pad = tools.GetBytes(pad_byte, pad_len) + hdr_len += pad_len + self.offset = len(content) + len(data) + hdr = struct.pack(FILE_HEADER_FORMAT, FILE_MAGIC, self.offset, self.ftype, attr_pos, hdr_len) - return hdr + name + attr + content + data + + # Do a sanity check of the get_header_len() function, to ensure that it + # stays in lockstep with this function + expected_len = self.get_header_len() + actual_len = len(hdr + name + attr) + if expected_len != actual_len: # pragma: no cover + # Test coverage of this is not available since this should never + # happen. It probably indicates that get_header_len() is broken. + raise ValueError("Internal error: CBFS file '%s': Expected headers of %#x bytes, got %#d" % + (self.name, expected_len, actual_len)) + return hdr + name + attr + pad + content + data class CbfsWriter(object): @@ -431,34 +494,39 @@ class CbfsWriter(object): if offset < self._size: self._skip_to(fd, offset) - def add_file_stage(self, name, data): + def add_file_stage(self, name, data, cbfs_offset=None): """Add a new stage file to the CBFS Args: name: String file name to put in CBFS (does not need to correspond to the name that the file originally came from) data: Contents of file + cbfs_offset: Offset of this file's data within the CBFS, in bytes, + or None to place this file anywhere Returns: CbfsFile object created """ - cfile = CbfsFile.stage(self._base_address, name, data) + cfile = CbfsFile.stage(self._base_address, name, data, cbfs_offset) self._files[name] = cfile return cfile - def add_file_raw(self, name, data, compress=COMPRESS_NONE): + def add_file_raw(self, name, data, cbfs_offset=None, + compress=COMPRESS_NONE): """Create a new raw file Args: name: String file name to put in CBFS (does not need to correspond to the name that the file originally came from) data: Contents of file + cbfs_offset: Offset of this file's data within the CBFS, in bytes, + or None to place this file anywhere compress: Compression algorithm to use (COMPRESS_...) Returns: CbfsFile object created """ - cfile = CbfsFile.raw(name, data, compress) + cfile = CbfsFile.raw(name, data, cbfs_offset, compress) self._files[name] = cfile return cfile @@ -507,7 +575,11 @@ class CbfsWriter(object): # Write out each file for cbf in self._files.values(): - fd.write(cbf.get_data()) + # Place the file at its requested place, if any + offset = cbf.calc_start_offset() + if offset is not None: + self._pad_to(fd, align_int_down(offset, self._align)) + fd.write(cbf.get_data(fd.tell(), self._erase_byte)) self._align_to(fd, self._align) if not self._hdr_at_start: self._write_header(fd, add_fileheader=self._add_fileheader) @@ -639,25 +711,27 @@ class CbfsReader(object): # Create the correct CbfsFile object depending on the type cfile = None - fd.seek(file_pos + offset, io.SEEK_SET) + cbfs_offset = file_pos + offset + fd.seek(cbfs_offset, io.SEEK_SET) if ftype == TYPE_CBFSHEADER: self._read_header(fd) elif ftype == TYPE_STAGE: data = fd.read(STAGE_LEN) - cfile = CbfsFile.stage(self.stage_base_address, name, b'') + cfile = CbfsFile.stage(self.stage_base_address, name, b'', + cbfs_offset) (cfile.compress, cfile.entry, cfile.load, cfile.data_len, cfile.memlen) = struct.unpack(STAGE_FORMAT, data) cfile.data = fd.read(cfile.data_len) elif ftype == TYPE_RAW: data = fd.read(size) - cfile = CbfsFile.raw(name, data, compress) + cfile = CbfsFile.raw(name, data, cbfs_offset, compress) cfile.decompress() if DEBUG: print('data', data) elif ftype == TYPE_EMPTY: # Just read the data and discard it, since it is only padding fd.read(size) - cfile = CbfsFile('', TYPE_EMPTY, b'') + cfile = CbfsFile('', TYPE_EMPTY, b'', cbfs_offset) else: raise ValueError('Unknown type %#x when reading\n' % ftype) if cfile: @@ -674,7 +748,8 @@ class CbfsReader(object): """Read attributes from the file CBFS files can have attributes which are things that cannot fit into the - header. The only attribute currently supported is compression. + header. The only attributes currently supported are compression and the + unused tag. Args: fd: File to read from @@ -703,6 +778,8 @@ class CbfsReader(object): # We don't currently use this information atag, alen, compress, _decomp_size = struct.unpack( ATTR_COMPRESSION_FORMAT, data) + elif atag == FILE_ATTR_TAG_UNUSED2: + break else: print('Unknown attribute tag %x' % atag) attr_size -= len(data) @@ -760,7 +837,7 @@ class CbfsReader(object): return val.decode('utf-8') -def cbfstool(fname, *cbfs_args): +def cbfstool(fname, *cbfs_args, **kwargs): """Run cbfstool with provided arguments If the tool fails then this function raises an exception and prints out the @@ -773,7 +850,9 @@ def cbfstool(fname, *cbfs_args): Returns: CommandResult object containing the results """ - args = ('cbfstool', fname) + cbfs_args + args = ['cbfstool', fname] + list(cbfs_args) + if kwargs.get('base') is not None: + args += ['-b', '%#x' % kwargs['base']] result = command.RunPipe([args], capture=not VERBOSE, capture_stderr=not VERBOSE, raise_on_error=False) if result.return_code: |