[PATCH v2 02/10] binman: Make compressed data header optional
Simon Glass
sjg at chromium.org
Sat Aug 13 16:59:20 CEST 2022
Hi Stefan,
On Mon, 8 Aug 2022 at 04:51, Stefan Herbrechtsmeier
<stefan.herbrechtsmeier-oss at weidmueller.com> wrote:
>
> From: Stefan Herbrechtsmeier <stefan.herbrechtsmeier at 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 at 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
More information about the U-Boot
mailing list