Flattened Device Tree Python Module

dtb-files, dts-files, fdt, kernel, python
pip install fdt==0.3.3


Flattened Device Tree Python Module

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This python module is usable for manipulation with Device Tree Data and primary was created for imxsb tool

Some parts in this module have been inspired from: https://github.com/superna9999/pyfdt project.


pip install fdt

To install the latest version from master branch execute in shell following command:

pip install -U https://github.com/molejar/pyFDT/archive/master.zip

In case of development, install it from cloned sources:

git clone https://github.com/molejar/pyFDT.git
cd pyFDT
pip install -U -e .

NOTE: You may run into a permissions issues running these commands. Here are a few options how to fix it:

  1. Run with sudo to install fdt and dependencies globally
  2. Specify the --user option to install locally into your home directory (export "~/.local/bin" into PATH variable if haven't).
  3. Run the command in a virtualenv local to a specific project working set.


fdt module has intuitive and self describing API, what is presented in following example. Many of general requirements for manipulation with FDT Nodes, Properties and dts/dtb files are already implemented.

  import fdt
  # convert *.dtb to *.dts
  # ----------------------------------------------
  with open("example.dtb", "rb") as f:
      dtb_data = f.read()

  dt1 = fdt.parse_dtb(dtb_data)
  with open("example.dts", "w") as f:

  # convert *.dts to *.dtb
  # ----------------------------------------------
  with open("example.dts", "r") as f:
      dts_text = f.read()

  dt2 = fdt.parse_dts(dts_text)
  with open("example.dtb", "wb") as f:

  # add new Node into dt2
  # ----------------------------------------------
  # create node instance
  node = fdt.Node('test_node1')
  # add properties
  node.append(fdt.PropStrings('string_property', 'value1', 'value2'))
  node.append(fdt.PropWords('words_property', 0x80000000))
  node.append(fdt.PropBytes('bytes_property', 0x00, 0x01, 0x02))
  # PropBytes constructor take also complex data object as bytes() or bytearray()
  node.append(fdt.PropBytes('bytes_property2', data=b"\x00\x01\x02"))
  # add created node into root path of dt2
  # use set_property method to update or create new property
  dt2.set_property('words_property', [0, 1], path='/test_node1')
  dt2.set_property('bytes_property', b"\x00\x01", path='/test_node1')
  dt2.set_property('string_property', ['value1', 'value2', 'value3'], path='/test_node1')  
  # use search method for find all string properties and then update it
  items = dt2.search("", itype=fdt.ItemType.PROP_STRINGS, path="/test_node1")
  for item in items:
    item.data = ['value1', 'value2']
  # merge dt2 into dt1
  # ----------------------------------------------

  with open("merged.dtb", "wb") as f:

  # diff two fdt objects
  # ----------------------------------------------
  out = fdt.diff(dt1, dt2)
  print(out[0]) # same in dt1 and dt2
  print(out[1]) # specific for dt1
  print(out[2]) # specific for dt2

[ pydtc ] Tool

The python device tree converter pydtc is a tool for conversion *.dts to *.dtb and vice versa. Is distributed together with fdt module. This tool can be in some cases used as replacement of device tree compiler.

  $ pydtc -h

usage: pydtc [-h] [-v] {pack,unpack,merge,diff} ...

Flat Device Tree (FDT) tool for manipulation with *.dtb and *.dts files

positional arguments:
    pack                Pack *.dts into binary blob (*.dtb)
    unpack              Unpack *.dtb into readable format (*.dts)
    merge               Merge more files in *.dtb or *.dts format
    diff                Compare two files in *.dtb or *.dts format

optional arguments:
  -h, --help            show this help message and exit
  -v, --version         show program's version number and exit

$ pydtc unpack [-h] [-s TAB_SIZE] [-o DTS_FILE] dtb_file

Unpack Device Tree from binary blob *.dtb into readable text file *.dts

dtb_file - Single DTB file with dtb extension

optional arguments:
  • -h, --help - Show this help message and exit
  • -s TAB_SIZE - Tabulator Size
  • -o DTS_FILE - Output path/file name (*.dts)
pydtc unpack test.dtb
DTS saved as: test.dts

$ pydtc pack [-h] [-v VERSION] [-l LC_VERSION] [-c CPU_ID] [-p] [-o DTB_FILE] dts_file

Pack Device Tree from readable text file *.dts into binary blob *.dtb

dts_file - Single DTS file as *.dts

optional arguments:
  • -h, --help - Show this help message and exit
  • -v VERSION - DTB Version
  • -l LC_VERSION - DTB Last Compatible Version
  • -c CPU_ID - Boot CPU ID
  • -p - Update phandle
  • -o DTB_FILE - Output path/file name (*.dtb)
pydtc pack -v 17 test.dts
DTB saved as: test.dtb

$ pydtc merge [-h] [-t {auto,dts,dtb}] [-s TAB_SIZE] out_file in_files [in_files ...]

Merge two and more *.dtb or *.dts files into one *.dts file

out_file - The output file name with *.dts extension
in_files - Two or more input files with *.dtb or *.dts extension

optional arguments:
  • -h, --help - Show this help message and exit
  • -t {auto,dts,dtb} - Input file type: 'auto', 'dts', 'dtb' (default: auto)
  • -s TAB_SIZE - Tabulator Size
pydtc merge out.dts test1.dtb test2.dtb
Output saved as: out.dts

$ pydtc diff [-h] [-t {auto,dts,dtb}] [-o OUT_DIR] in_file1 in_file2

Compare two dtb/dts files and generate 3 dts files (same in 1 and 2, specific for 1, specific for 2)

in_file1 - Input file 1
in_file2 - Input file 2

optional arguments:
  • -h, --help - Show this help message and exit
  • -t {auto,dts,dtb} - Input file type: 'auto', 'dts', 'dtb' (default: auto)
  • -o OUT_DIR - Output directory (default: diff_out)
pydtc diff test1.dtb test2.dtb
Output saved into: diff_out