tree: 2885f5f324e88d1ef9524c91ef8acbc9fa8fafb0 [path history] [tgz]
  1. Documentation/
  2. fuzzing/
  3. libfdt/
  4. pylibfdt/
  5. scripts/
  6. tests/
  7. .cirrus.yml
  8. .editorconfig
  9. .gitignore
  10. .travis.yml
  11. Android.bp
  12. BSD-2-Clause
  13. checks.c
  14. CONTRIBUTING.md
  15. convert-dtsv0-lexer.l
  16. data.c
  17. dtc-lexer.l
  18. dtc-parser.y
  19. dtc.c
  20. dtc.h
  21. dtdiff
  22. fdtdump.c
  23. fdtget.c
  24. fdtoverlay.c
  25. fdtput.c
  26. flattree.c
  27. fstree.c
  28. GPL
  29. LGPL
  30. LICENSE
  31. livetree.c
  32. Makefile
  33. Makefile.convert-dtsv0
  34. Makefile.dtc
  35. Makefile.utils
  36. MANIFEST.in
  37. meson.build
  38. meson_options.txt
  39. METADATA
  40. MODULE_LICENSE_BSD
  41. MODULE_LICENSE_GPL
  42. MODULE_LICENSE_LGPL
  43. OWNERS
  44. README.license
  45. README.md
  46. README.version
  47. setup.py
  48. srcpos.c
  49. srcpos.h
  50. TODO
  51. treesource.c
  52. util.c
  53. util.h
  54. version_gen.h.in
  55. version_non_gen.h
  56. yamltree.c
README.md

Device Tree Compiler and libfdt

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:

Python library

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.

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