Device Tree frowand

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Top Device Tree page

Device Tree stuff from Frank Rowand

Resources for "Solving Device Tree Issues" talk

Updates on tools shown in the talk

dtdiff           - in linux source tree as scripts/dtc/dtx_diff,  merged 4.6-rc1

dtc --annotate   - remains a proof of concept

dt_node_info     - remains a proof of concept
dt_stat

dt_to_config     - vastly improved, v2 submitted to mainline, might land in 4.8-rc1

Another option for uploading FDT and EDT from a target over a serial console is serio.

Embedded Linux Conference Europe (ELCE) - October 6, 2015

Linuxcon North America / Linux Plumbers Conference refereed track - August 19, 2015

LinuxCon Japan - June 4, 2015

Resources for "Solving Device Tree Issues - Part 2" talk

dt_to_config is not upstream yet is upstream in Linux 4.8-rc1. It is also available here:

dt_to_config requires scripts/dtc/dtx_diff, which is available in Linux 4.6-rc1 and later.

devicetree man pages

man pages for devicetree are a work in progress. This is a workspace to hold current progress until the work is mainlined. Source files are being added to the list of files processed by docbook as the docbook comments in the source files are updated. man pages are not created for source files that have not been audited.

The current version of the man pages is:

The man pages are created from the docbook comments in the Linux kernel source.

The man pages are available in two formats

  • html
  • via the man command.

installing and using the html man pages

create a location to download and install

  • pick a location, I use 'me/devicetree_docs'
    • dest_relative="me/devicetree_docs"
  • create the location
    • dest="$(pwd)/${dest_relative}"
    • mkdir -p ${dest_relative}
    • cd ${dest}

Download the tar containing the html tar, the man tar, and the patches tar to the current directory

unpack the individual tars from the bundle

  • tar -xf Docbook_devicetree_160620_0145.tar

unpack the html tar

  • tar -xf docbook_devicetree_html_160620_0145.tgz

determine the URL to use to access the man pages

  • echo "file://${dest}/devicetree.html"

enter the above URL in your favorite browser

installing and using the man command pages

create a location to download and install

  • pick a location, I use 'me/devicetree_docs'
    • dest_relative="me/devicetree_docs"
  • create the location
    • dest="$(pwd)/${dest_relative}"
    • mkdir -p ${dest_relative}
    • cd ${dest}

Download the tar containing the html tar, the man tar, and the patches tar to the current directory

unpack the individual tars from the bundle

  • tar -xf Docbook_devicetree_160620_0145.tar

unpack the man tar

  • tar -xf docbook_devicetree_man_160620_0145.tgz

create the directory tree that the man command expects

  • ln -s devicetree man/man9

use the man command in one of two ways 

MANPATH="${dest}/man" man OF_FUNCTION
   eg.
   MANPATH="${dest}/man" man of_node_get



export MANPATH="${dest}/man"
man OF_FUNCTION
  eg
  export MANPATH="${dest}/man"
  man of_node_get
  man of_node_put

installing the source patches and building the docbook results

If you want to compile the docbook results yourself, do the following.

Download the Linux kernel source tree

Download the tar containing the html tar, the man tar, and the patches tar to the current directory

Unpack the individual tars from the bundle

  • tar -xf Docbook_devicetree_160620_0145.tar

Unpack the source patches tar

  • tar -xf docbook_devicetree_patch_160620_0145.tgz

Apply the patches

  • quilt push -a
If you do not have quilt installed, you can instead apply each of the
patches in patches/.  Apply the patches in the order listed in
patches/series.

Build the docbook targets

  • mkdir ../build
  • export KBUILD_OUTPUT=../build
  • make DOCBOOKS="devicetree.xml" mandocs
  • make DOCBOOKS="devicetree.xml" htmldocs

The generated objects will be under the build directory ../build/Documentation/DocBook/

image test

flowers in the desert

This is a photograph from one of my desert trips. If you have arrived early to one of my conference talks, you have probably seen photos from my desert trips. 

This spot of color is low in the hills
of Death Valley.


temporary parking spot

Links to pages that are under construction, so that the pages will not get deleted.

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