Re: [PATCH v2 02/10] binman: Make compressed data header optional

Hi Stefan,

On Mon, 8 Aug 2022 at 04:51, Stefan Herbrechtsmeier stefan.herbrechtsmeier-oss@weidmueller.com wrote:

From: Stefan Herbrechtsmeier stefan.herbrechtsmeier@weidmueller.com

Move the compressed data header handling into the dtb blob entry class and make it optional. The header is uncommon, not supported by U-Boot and incompatible with external compressed artifacts.

If needed the header could be enabled with the following attribute beside the compress attribute: prepend = "length";

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 any compressed data by itself.

Signed-off-by: Stefan Herbrechtsmeier stefan.herbrechtsmeier@weidmueller.com

---

Changes in v2:

• Reworked to make the feature optional.

tools/binman/cbfs_util.py | 8 ++--- tools/binman/comp_util.py | 11 ++---- tools/binman/entries.rst | 4 +++ tools/binman/entry.py | 2 +- tools/binman/etype/blob_dtb.py | 21 ++++++++++++ tools/binman/ftest.py | 34 ++++++++++++++++--- .../test/235_compress_prepend_length_dtb.dts | 17 ++++++++++ 7 files changed, 78 insertions(+), 19 deletions(-) create mode 100644 tools/binman/test/235_compress_prepend_length_dtb.dts

I've been through this and I think it is a good change. We can use your technique (property in the blob_dtb etype) to deal with any future problems that come up.

But I would like to split this patch into three:

1. Add your blob_dtb property and the test 2. Change all uses of compress()/decompress() to call with add with_header=False 3. Drop the with_header arg from comp_util.py

A few more tweaks below.

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/entries.rst b/tools/binman/entries.rst index ae4305c99e..8e722426d3 100644 --- a/tools/binman/entries.rst +++ b/tools/binman/entries.rst @@ -208,6 +208,10 @@ This is a blob containing a device tree. The contents of the blob are obtained from the list of available device-tree files, managed by the 'state' module.

+Additional Properties / Entry arguments:

• • prepend: Header type to use:

•    none: No header
  

•    length: 32-bit length header
  
  
  

Entry: blob-ext: Externally built binary blob 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':
  

diff --git a/tools/binman/etype/blob_dtb.py b/tools/binman/etype/blob_dtb.py index 4159e3032a..652b8abd8f 100644 --- a/tools/binman/etype/blob_dtb.py +++ b/tools/binman/etype/blob_dtb.py @@ -7,6 +7,8 @@

from binman.entry import Entry from binman.etype.blob import Entry_blob +from dtoc import fdt_util +import struct

# This is imported if needed state = None @@ -17,6 +19,9 @@ class Entry_blob_dtb(Entry_blob): This is a blob containing a device tree. The contents of the blob are obtained from the list of available device-tree files, managed by the 'state' module.

• Additional attributes:

•    prepend: Header used (e.g. 'length'), 'none' if none
  

  """ def __init__(self, section, etype, node): # Put this here to allow entry-docs and help to work without libfdt

@@ -25,6 +30,12 @@ class Entry_blob_dtb(Entry_blob):

     super().__init__(section, etype, node)

•    self.prepend = 'none'
  

None ?

• def ReadNode(self):

•    super().ReadNode()
  

•    self.prepend = fdt_util.GetString(self._node, 'prepend', 'none')
  

Can you drop the 'none' so that it uses None instead?

Aso we should check for a valid value here - e.g. it must be 'length' and not something else, otherwise self.Raise()

• def ObtainContents(self): """Get the device-tree from the list held by the 'state' module""" self._filename = self.GetDefaultFilename()

@@ -35,6 +46,9 @@ class Entry_blob_dtb(Entry_blob): """Re-read the DTB contents so that we get any calculated properties""" _, indata = state.GetFdtContents(self.GetFdtEtype()) data = self.CompressData(indata)

•    if self.prepend == 'length':
  

•        hdr = struct.pack('<I', len(data))
  

•        data = hdr + data
     return self.ProcessContentsUpdate(data)
  
  

  def GetFdtEtype(self):

@@ -50,6 +64,13 @@ class Entry_blob_dtb(Entry_blob): fname = self.GetDefaultFilename() return {self.GetFdtEtype(): [self, fname]}

• def ReadData(self, decomp=True, alt_format=None):

•    data = super().ReadData(decomp, alt_format)
  

•    if self.prepend == 'length':
  

•        data_len = struct.unpack('<I', data[:4])[0]
  

•        data = data[4:4 + data_len]
  

•    return data
  

• def WriteData(self, data, decomp=True): ok = super().WriteData(data, decomp)

diff --git a/tools/binman/ftest.py b/tools/binman/ftest.py index da9aa9e679..057b4e28b7 100644 --- a/tools/binman/ftest.py +++ b/tools/binman/ftest.py @@ -2536,6 +2536,28 @@ class TestFunctional(unittest.TestCase): } self.assertEqual(expected, props)

• def testCompressPrependLengthDtb(self):

•    """Test that compress of device-tree files with length header is
  

•    supported
  

•    """
  

•    data = self.data = self._DoReadFileRealDtb('235_compress_prepend_length_dtb.dts')
  

•    self.assertEqual(U_BOOT_DATA, data[:len(U_BOOT_DATA)])
  

•    dtb_data = data[len(U_BOOT_DATA):]
  

•    comp_data_len = struct.unpack('<I', dtb_data[:4])[0]
  

•    comp_data = dtb_data[4:4 + comp_data_len]
  

•    orig = self._decompress(comp_data)
  

•    dtb = fdt.Fdt.FromData(orig)
  

•    dtb.Scan()
  

•    props = self._GetPropTree(dtb, ['size', 'uncomp-size'])
  

•    expected = {
  

•        'u-boot:size': len(U_BOOT_DATA),
  

•        'u-boot-dtb:uncomp-size': len(orig),
  

•        'u-boot-dtb:size': len(dtb_data),
  

•        'size': len(data),
  

•        }
  

•    self.assertEqual(expected, props)
  

• def testCbfsUpdateFdt(self): """Test that we can update the device tree with CBFS offset/size info""" self._CheckLz4()

@@ -2856,7 +2878,7 @@ class TestFunctional(unittest.TestCase): def testExtractCbfsRaw(self): """Test extracting CBFS compressed data without decompressing it""" data = self._RunExtractCmd('section/cbfs/u-boot-dtb', decomp=False)

•    dtb = comp_util.decompress(data, 'lzma', with_header=False)
  

•    dtb = comp_util.decompress(data, 'lzma')
     self.assertEqual(EXTRACT_DTB_SIZE, len(dtb))
  
  

  def testExtractBadEntry(self):

@@ -4427,15 +4449,17 @@ class TestFunctional(unittest.TestCase): rest = base[len(U_BOOT_DATA):]

     # Check compressed data

•    section1 = self._decompress(rest)
     expect1 = comp_util.compress(COMPRESS_DATA + U_BOOT_DATA, 'lz4')
  

•    self.assertEquals(expect1, rest[:len(expect1)])
  

•    data1 = rest[:len(expect1)]
  

•    section1 = self._decompress(data1)
  

•    self.assertEquals(expect1, data1)
     self.assertEquals(COMPRESS_DATA + U_BOOT_DATA, section1)
     rest1 = rest[len(expect1):]
  
  

•    section2 = self._decompress(rest1)
     expect2 = comp_util.compress(COMPRESS_DATA + COMPRESS_DATA, 'lz4')
  

•    self.assertEquals(expect2, rest1[:len(expect2)])
  

•    data2 = rest1[:len(expect2)]
  

•    section2 = self._decompress(data2)
  

•    self.assertEquals(expect2, data2)
     self.assertEquals(COMPRESS_DATA + COMPRESS_DATA, section2)
     rest2 = rest1[len(expect2):]
  
  

diff --git a/tools/binman/test/235_compress_prepend_length_dtb.dts b/tools/binman/test/235_compress_prepend_length_dtb.dts new file mode 100644 index 0000000000..a5abc60477 --- /dev/null +++ b/tools/binman/test/235_compress_prepend_length_dtb.dts @@ -0,0 +1,17 @@ +// SPDX-License-Identifier: GPL-2.0+

+/dts-v1/;

+/ {

•   #address-cells = <1>;
  

•   #size-cells = <1>;
  

•   binman {
  

•           u-boot {
  

•           };
  

•           u-boot-dtb {
  

•                   compress = "lz4";
  

•                   prepend = "length";
  

•           };
  

•   };
  

+};

2.30.2

Regards, Simon