| commit | 7eeadceb3eecdc37e19105d577dd2835a4babc53 | [log] [tgz] |
|---|---|---|
| author | Pierre-Clément Tosi <ptosi@google.com> | Wed Oct 11 14:09:22 2023 +0100 |
| committer | Pierre-Clément Tosi <ptosi@google.com> | Wed Oct 11 19:15:08 2023 +0100 |
| tree | 83571d7555e1a13c64e66e7d6f2c3cbc6db4461b | |
| parent | c8d1d863ab72b74efe7bda4c80579968716708a6 [diff] |
ANDROID: Generate version_gen.h in Soong and Bazel
Upstream provides a DTC_VERSION preprocessor macro to its C code by
generating a version_gen.h header from either of its supported build
systems: Make formats the header from its internal variables (VERSION,
PATCHLEVEL, SUBLEVEL, ...) while Meson uses its vcs_tag() function on
a template, version_gen.h.in.
As AOSP doesn't make use of these build systems, aosp/204511 decided to
hardcode a version_non_gen.h file and patch the corresponding #include.
This unsurprisingly ended up bitrotting as the repo was being upgraded.
Instead, replicate the version_gen.h.in patching in our build systems,
extracting the version number from the METADATA file, which
external_updater.sh will keep up-to-date. Note that this introduces a
dependency on sed in the genrule(), the impact of which is minimized by
making METADATA_version.sed POSIX-compliant.
Keep appending the suffix '-Android-build' to the upstream version.
Test: m dtc && ${ANDROID_HOST_OUT}/bin/dtc --version
Test: bazel build //:dtc && bazel-bin/dtc --version
Change-Id: I6b780c1dbe14d415891defeb652f0692988ed0b1
The source tree contains the Device Tree Compiler (dtc) toolchain for working with device tree source and binary files and also libfdt, a utility library for reading and manipulating the binary format.
dtc and libfdt are maintained by:
A Python library wrapping libfdt is also available. To build this you will need to install swig and Python development files. On Debian distributions:
$ sudo apt-get install swig python3-dev
The library provides an Fdt class which you can use like this:
$ PYTHONPATH=../pylibfdt python3
>>> import libfdt
>>> fdt = libfdt.Fdt(open('test_tree1.dtb', mode='rb').read())
>>> node = fdt.path_offset('/subnode@1')
>>> print(node)
124
>>> prop_offset = fdt.first_property_offset(node)
>>> prop = fdt.get_property_by_offset(prop_offset)
>>> print('%s=%s' % (prop.name, prop.as_str()))
compatible=subnode1
>>> node2 = fdt.path_offset('/')
>>> print(fdt.getprop(node2, 'compatible').as_str())
test_tree1
You will find tests in tests/pylibfdt_tests.py showing how to use each method. Help is available using the Python help command, e.g.:
$ cd pylibfdt $ python3 -c "import libfdt; help(libfdt)"
If you add new features, please check code coverage:
$ sudo apt-get install python3-coverage $ cd tests # It's just 'coverage' on most other distributions $ python3-coverage run pylibfdt_tests.py $ python3-coverage html # Open 'htmlcov/index.html' in your browser
The library can be installed with pip from a local source tree:
$ pip install . [--user|--prefix=/path/to/install_dir]
Or directly from a remote git repo:
$ pip install git+git://git.kernel.org/pub/scm/utils/dtc/dtc.git@main
The install depends on libfdt shared library being installed on the host system first. Generally, using --user or --prefix is not necessary and pip will use the default location for the Python installation which varies if the user is root or not.
You can also install everything via make if you like, but pip is recommended.
To install both libfdt and pylibfdt you can use:
$ make install [PREFIX=/path/to/install_dir]
To disable building the python library, even if swig and Python are available, use:
$ make NO_PYTHON=1
More work remains to support all of libfdt, including access to numeric values.