binman: Support replacing data in a cbfs
At present binman cannot replace data within a CBFS since it does not
allow rewriting of the files in that CBFS. Implement this by using the
new WriteData() method to handle the case.
Add a header to compressed data so that the amount of compressed data can
be determined without reference to the size of the containing entry. This
allows the entry to be larger that the contents, without causing errors in
decompression. This is necessary to cope with a compressed device tree
being updated in such a way that it shrinks after the entry size is
already set (an obscure case). It is not used with CBFS since it has its
own metadata for this. Increase the number of passes allowed to resolve
the position of entries, to handle this case.
Add a test for this new logic.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/patman/tools.py b/tools/patman/tools.py
index f492dc8..d615227 100644
--- a/tools/patman/tools.py
+++ b/tools/patman/tools.py
@@ -9,6 +9,7 @@
import glob
import os
import shutil
+import struct
import sys
import tempfile
@@ -377,7 +378,7 @@
return string.encode('utf-8')
return string
-def Compress(indata, algo):
+def Compress(indata, algo, with_header=True):
"""Compress some data using a given algorithm
Note that for lzma this uses an old version of the algorithm, not that
@@ -408,9 +409,12 @@
data = Run('gzip', '-c', fname, binary=True)
else:
raise ValueError("Unknown algorithm '%s'" % algo)
+ if with_header:
+ hdr = struct.pack('<I', len(data))
+ data = hdr + data
return data
-def Decompress(indata, algo):
+def Decompress(indata, algo, with_header=True):
"""Decompress some data using a given algorithm
Note that for lzma this uses an old version of the algorithm, not that
@@ -428,6 +432,9 @@
"""
if algo == 'none':
return indata
+ if with_header:
+ data_len = struct.unpack('<I', indata[:4])[0]
+ indata = indata[4:4 + data_len]
fname = GetOutputFilename('%s.decomp.tmp' % algo)
with open(fname, 'wb') as fd:
fd.write(indata)