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qemu / dtc / ae26223a056e040b2d812202283d47c6e034d063
commitae26223a056e040b2d812202283d47c6e034d063[log] [tgz]
authorZheng Guangyuan <1628513611@qq.com>Sun Apr 28 13:44:57 2024 +0800
committerDavid Gibson <david@gibson.dropbear.id.au>Wed May 01 16:50:50 2024 +1000
treec49c0088f8f3b53305a18cb29da9fbc20a3ecfa2
parent4dd831affd015efbb6e0a56d55ac5ef7812af97a [diff]
libfdt: overlay: Refactor overlay_fixup_phandle

Refactored overlay_fixup_phandle to optimize efficiency by moving the
phandle lookup logic based on label outside the overlay_fixup_one_phandle call.
This avoids redundant phandle lookups when a single label is associated with multiple modifications.

Signed-off-by: Zheng Guangyuan <1628513611@qq.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
1 file changed
tree: c49c0088f8f3b53305a18cb29da9fbc20a3ecfa2
  1. .github/
  2. Documentation/
  3. libfdt/
  4. pylibfdt/
  5. scripts/
  6. tests/
  7. .editorconfig
  8. .gitignore
  9. BSD-2-Clause
  10. checks.c
  11. CONTRIBUTING.md
  12. convert-dtsv0-lexer.l
  13. data.c
  14. dtc-lexer.l
  15. dtc-parser.y
  16. dtc.c
  17. dtc.h
  18. dtdiff
  19. fdtdump.c
  20. fdtget.c
  21. fdtoverlay.c
  22. fdtput.c
  23. flattree.c
  24. fstree.c
  25. GPL
  26. livetree.c
  27. Makefile
  28. Makefile.convert-dtsv0
  29. Makefile.dtc
  30. Makefile.utils
  31. MANIFEST.in
  32. meson.build
  33. meson_options.txt
  34. README.license
  35. README.md
  36. setup.py
  37. srcpos.c
  38. srcpos.h
  39. TODO
  40. treesource.c
  41. util.c
  42. util.h
  43. VERSION.txt
  44. version_gen.h.in
  45. 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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