Skip to main content

A library for parsing Devicetree Source v1

Project description

pydevicetree

This is a Python 3 library for parsing, querying, and modifying Devicetree Source v1 files as described in the Devicetree Specification v0.2.

Install

pydevicetree supports Python >= 3.5 and can be installed with pip from the Python Package Index.

pip install pydevicetree

Tutorial

The Devicetree

Let's say you have a file design.dts with the contents

/dts-v1/;

/ {
	#address-cells = <1>;
	#size-cells = <1>;
	compatible = "my,design";
	aliases {
		serial0 = "/soc/uart@10000000";
	};
	chosen {
		stdout-path = "/soc/uart@10000000:115200";
	};
	cpus {
		#address-cells = <1>;
		#size-cells = <0>;
		cpu@0 {
			compatible = "sifive,rocket0", "riscv";
			device_type = "cpu";
			reg = <0>;
			riscv,isa = "rv32imac";
			status = "okay";
			timebase-frequency = <1000000>;
			sifive,dtim = <&dtim>;
			interrupt-controller {
				#interrupt-cells = <1>;
				compatible = "riscv,cpu-intc";
				interrupt-controller;
			};
		};
	};
	soc {
		#address-cells = <1>;
		#size-cells = <1>;
		compatible = "my,design-soc";
		ranges;
		dtim: dtim@20000000 {
			compatible = "sifive,dtim0";
			reg = <0x20000000 0x10000000>;
			reg-names = "mem";
		};
		uart: uart@10000000 {
			compatible = "sifive,uart0";
			reg = <0x10000000 0x1000>;
			reg-names = "control";
		};
	};
};

Parsing the Tree

Parsing the tree is as easy as 1, 2...

>>> from pydevicetree import Devicetree
>>> tree = Devicetree.parseFile("design.dts")
>>> tree
<Devicetree my,design>

Querying the Tree

By compatible string

>>> tree.match("sifive,rocket0")
[<Node cpu>]

By path

>>> tree.get_by_path("/soc/dtim")
<Node dtim@20000000>

Devicetree aliases are allowed in paths

>>> tree.get_by_path("serial0")
<Node uart@10000000>

Getting Node properties

The value (or first value of a list/array) of a property can be retrieved with Node.get_field()

>>> tree.match("sifive,rocket0")[0].get_field("timebase-frequency")
1000000

The list or array of values assigned to a property can be retrieved with Node.get_fields()

>>> tree.match("sifive,rocket0")[0].get_fields("compatible")
<StringList ['sifive,rocket0', 'riscv']>

There are helper methods Node.get_reg() and Node.get_ranges() for the reg and ranges Devicetree properties.

>>> tree.get_by_path("/soc/dtim").get_reg()
<RegArray [536870912, 268435456]>
>>> tree.get_by_path("/soc/dtim").get_reg().get_by_name("mem")
(536870912, 268435456)
>>> "0x%x" % tree.get_by_path("/soc/dtim").get_reg().get_by_name("mem")[0]
'0x20000000'

Getting chosen properties

Devicetree.chosen() provides quick access to the properties of the chosen node

>>> tree.chosen("stdout-path")
<StringList ['/soc/uart@10000000:115200']>

Converting back to Devicetree

Any tree or subtree can be converted back to Devicetree by calling Node.to_dts() or simply by printing it:

>>> print(tree.match("sifive,rocket0")[0])
cpu@0 {
        #size-cells = <0>;
        compatible = "sifive,rocket0", "riscv";
        device_type = "cpu";
        reg = <0x0>;
        riscv,isa = "rv32imac";
        status = "okay";
        timebase-frequency = <1000000>;
        sifive,dtim = <&dtim>;
        interrupt-controller {
                #interrupt-cells = <1>;
                compatible = "riscv,cpu-intc";
                interrupt-controller;
        };
};

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

pydevicetree-0.0.12.tar.gz (25.7 kB view hashes)

Uploaded source

Built Distribution

pydevicetree-0.0.12-py3-none-any.whl (26.4 kB view hashes)

Uploaded py3

Supported by

AWS AWS Cloud computing Datadog Datadog Monitoring Facebook / Instagram Facebook / Instagram PSF Sponsor Fastly Fastly CDN Google Google Object Storage and Download Analytics Huawei Huawei PSF Sponsor Microsoft Microsoft PSF Sponsor NVIDIA NVIDIA PSF Sponsor Pingdom Pingdom Monitoring Salesforce Salesforce PSF Sponsor Sentry Sentry Error logging StatusPage StatusPage Status page