fdtoverlaymerge: A tool that merges overlays

fdtoverlaymerge is a command-line tool that merges two or more overlay blobs
by making use of fdt_overlay_merge() API

Change-Id: Idcd46e630436681a4bc640e7b53bc225cf5e4287
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
Signed-off-by: Rama Aparna Mallavarapu <aparnam@codeaurora.org>
3 files changed
tree: 1e905be9c2cc9f3fbf89fa1c4bf216b612c1cbe4
  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. BUILD.bazel
  14. checks.c
  15. CONTRIBUTING.md
  16. convert-dtsv0-lexer.l
  17. data.c
  18. dtc-lexer.l
  19. dtc-parser.y
  20. dtc.c
  21. dtc.h
  22. dtdiff
  23. fdtdump.c
  24. fdtget.c
  25. fdtoverlay.c
  26. fdtoverlaymerge.c
  27. fdtput.c
  28. flattree.c
  29. fstree.c
  30. GPL
  31. LGPL
  32. LICENSE
  33. livetree.c
  34. Makefile
  35. Makefile.convert-dtsv0
  36. Makefile.dtc
  37. Makefile.utils
  38. MANIFEST.in
  39. meson.build
  40. meson_options.txt
  41. METADATA
  42. METADATA_version.sed
  43. MODULE_LICENSE_BSD
  44. MODULE_LICENSE_GPL
  45. MODULE_LICENSE_LGPL
  46. OWNERS
  47. README.license
  48. README.md
  49. README.version
  50. setup.py
  51. srcpos.c
  52. srcpos.h
  53. TODO
  54. treesource.c
  55. util.c
  56. util.h
  57. version_gen.h.in
  58. WORKSPACE
  59. 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.

Mailing lists