[PATCH 2/3] binman: Remove header from compressed data

[Stefan Herbrechtsmeier]

From: Stefan Herbrechtsmeier <stefan.herbrechtsmeier at weidmueller.com>

Remove header from compressed data because this is uncommon, not
supported by U-Boot and incompatible with external compressed artifacts.

The header was introduced as part of commit eb0f4a4cb402 ("binman:
Support replacing data in a cbfs") to allow device tree entries to be
larger that the compressed contents. Regarding the commit "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)". This case need to be fixed without influence the compressed data
by itself.

Signed-off-by: Stefan Herbrechtsmeier <stefan.herbrechtsmeier at weidmueller.com>

---

 tools/binman/cbfs_util.py |  8 ++++----
 tools/binman/comp_util.py | 11 ++---------
 tools/binman/entry.py     |  2 +-
 3 files changed, 7 insertions(+), 14 deletions(-)

diff --git a/tools/binman/cbfs_util.py b/tools/binman/cbfs_util.py
index 9cad03886f..a1836f4ad3 100644
--- a/tools/binman/cbfs_util.py
+++ b/tools/binman/cbfs_util.py
@@ -241,9 +241,9 @@ class CbfsFile(object):
         """Handle decompressing data if necessary"""
         indata = self.data
         if self.compress == COMPRESS_LZ4:
-            data = comp_util.decompress(indata, 'lz4', with_header=False)
+            data = comp_util.decompress(indata, 'lz4')
         elif self.compress == COMPRESS_LZMA:
-            data = comp_util.decompress(indata, 'lzma', with_header=False)
+            data = comp_util.decompress(indata, 'lzma')
         else:
             data = indata
         self.memlen = len(data)
@@ -362,9 +362,9 @@ class CbfsFile(object):
         elif self.ftype == TYPE_RAW:
             orig_data = data
             if self.compress == COMPRESS_LZ4:
-                data = comp_util.compress(orig_data, 'lz4', with_header=False)
+                data = comp_util.compress(orig_data, 'lz4')
             elif self.compress == COMPRESS_LZMA:
-                data = comp_util.compress(orig_data, 'lzma', with_header=False)
+                data = comp_util.compress(orig_data, 'lzma')
             self.memlen = len(orig_data)
             self.data_len = len(data)
             attr = struct.pack(ATTR_COMPRESSION_FORMAT,
diff --git a/tools/binman/comp_util.py b/tools/binman/comp_util.py
index dc76adab35..269bbf7975 100644
--- a/tools/binman/comp_util.py
+++ b/tools/binman/comp_util.py
@@ -3,7 +3,6 @@
 #
 """Utilities to compress and decompress data"""
 
-import struct
 import tempfile
 
 from binman import bintool
@@ -16,7 +15,7 @@ LZMA_ALONE = bintool.Bintool.create('lzma_alone')
 HAVE_LZMA_ALONE = LZMA_ALONE.is_present()
 
 
-def compress(indata, algo, with_header=True):
+def compress(indata, algo):
     """Compress some data using a given algorithm
 
     Note that for lzma this uses an old version of the algorithm, not that
@@ -41,12 +40,9 @@ def compress(indata, algo, with_header=True):
         data = LZMA_ALONE.compress(indata)
     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, with_header=True):
+def decompress(indata, algo):
     """Decompress some data using a given algorithm
 
     Note that for lzma this uses an old version of the algorithm, not that
@@ -64,9 +60,6 @@ def decompress(indata, algo, with_header=True):
     """
     if algo == 'none':
         return indata
-    if with_header:
-        data_len = struct.unpack('<I', indata[:4])[0]
-        indata = indata[4:4 + data_len]
     if algo == 'lz4':
         data = LZ4.decompress(indata)
     elif algo == 'lzma':
diff --git a/tools/binman/entry.py b/tools/binman/entry.py
index a07a588864..8cbfd43af9 100644
--- a/tools/binman/entry.py
+++ b/tools/binman/entry.py
@@ -1069,7 +1069,7 @@ features to produce new behaviours.
             indata: Data to compress
 
         Returns:
-            Compressed data (first word is the compressed size)
+            Compressed data
         """
         self.uncomp_data = indata
         if self.compress != 'none':
-- 
2.30.2