Commit graph

10 commits

Author SHA1 Message Date
Martí Bolívar
5272e7f681 dtlib: add DT.move_node()
This helper lets you place a node (really the entire subtree rooted at
that node) elsewhere in the devicetree. This will be useful when
adding system devicetree support, when we'll want to be able to, for
example, move the CPU cluster node selected by the current execution
domain to /cpus.

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>
2023-02-27 17:44:45 +01:00
Martí Bolívar
e479d3f7c6 dtlib: use new helper in test cases
Using dtlib_raises() throughout the test cases saves some typing.

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>
2023-02-27 17:44:45 +01:00
Martí Bolívar
2063ddbc93 dtlib: add new test case helper
Introduce a context manager that will save some typing
when dealing with expected exceptions.

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>
2023-02-27 17:44:45 +01:00
Martí Bolívar
15e3e317f7 dtlib: implement copy.deepcopy() for DT
The standard library copy module allows you to implement shallow and
deep copies of objects. See its documentation for more details on
these terms.

Implementing copy.deepcopy() support for DT objects will allow us to
"clone" devicetree objects in other classes. This in turn will enable
new features, such as native system devicetree support, within the
python-devicetree.

It is also a pure feature extension which can't harm anything and is
therefore safe to merge now, even if system devicetree is never
adopted in Zephyr.

Note that we are making use of the move from OrderedDict to regular
dict to make this implementation more convenient.

See https://github.com/devicetree-org/lopper/ for more information on
system devicetree. We want to add system devicetree support to dtlib
because it seems to be a useful way to model modern, heterogeneous
SoCs than traditional devicetree, which can really only model a single
CPU "cluster" within such an SoC.

In order to create 'regular' devicetrees from a system devicetree, we
will want a programming interface that does the following:

   1. parse the system devicetree
   2. receive the desired transformations on it
   3. perform the desired transformations to make
      a 'regular' devicetree

Step 3 can be done as a destructive modification on an object-oriented
representation of a system devicetree, and that's the approach we will
take in python-devicetree. It will therefore be convenient to have an
efficient deepcopy implementation to be able to preserve the original
system devicetree and the derived regular devicetree in memory in the
same python process.

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>
2022-11-07 19:00:31 +01:00
Martí Bolívar
22012894c0 dtlib: error out on duplicate node names
Attempts to define two nodes with the same name within a single set of
curly brackets should fail.

For example, this is invalid DTS according to dtc:

    / { foo {}; foo {}; };

By contrast, this is valid since the node named 'foo' appears twice in
two different sets of curly brackets:

    / { foo {}; };
    / { foo {}; };

Zephyr's dtlib currently does not error out on the invalid condition.

Now that Zephyr itself has been updated to not include such nodes (to
the best of my ability), we can fix this divergence from current dtc
behavior and add a regression test in dtlib.

Fixes: #49590
Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>
2022-09-21 07:55:40 -07:00
Martí Bolívar
ffa1515978 dtlib: fix issue which allowed invalid node names
Node names are subject to the rules in table 2.1 of the devicetree
specification v0.3, while properties are subject to rules in table
2.2. These rules mean that some property names are invalid node names.

However, the same regular expression is being used to validate the
names of nodes and properties in dtlib. This leads to invalid node
names being allowed to pass. Fix this issue by moving the node name
handling code to the Node constructor and checking against the
characters in table 2.1.

The test cases claim that the existing behavior matches dtc. I can't
reproduce that. I get errors when I use invalid characters (like "?")
in a node name. For example:

foo.dts:3.8-11: ERROR (node_name_chars): /node?: Bad character '?' in
node name

Try to make the dtlib error message reminiscent of that.

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>
2021-08-31 19:36:31 -04:00
Martí Bolívar
15db98a400 dtlib: allow dangling aliases with DT(..., force=True)
As a first step towards being more forgiving on invalid inputs, allow
string-valued aliases properties that do not point to valid nodes when
the user requests permissiveness.

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>
2021-07-14 19:51:46 -04:00
Martí Bolívar
b13b5b8b3a dtlib: fix include_path edge case
The documentation says DT.__init__ takes any iterable for the
include_path, but this leads to bad results when you pass it something
other than a 'real' sequence (list/tuple/etc), like a generator:

>>> dt = DT('/tmp/foo.dts', (x for x in ['a', 'b', 'c']))
>>> repr(dt)
"DT(filename='/tmp/foo.dts', include_path=<generator object ...>)"

Make a copy in list form just to avoid things like this.

Add a test for this and relax the regular expression in the existing
test case related to this.

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>
2021-05-05 13:13:12 -05:00
Martí Bolívar
74f95688d9 dtlib: add Type enum
Instead of hard-coding constants, use an IntEnum.

These is still a subclass of 'int', but is both easier to import and
easier to read during debugging.

For example, compare:

>>> Type.BYTES
<Type.BYTES: 1>

with:

>>> TYPE_BYTES
1

However, 'Type.BYTES == 1' is still True, and the enum values
otherwise behave like you would expect.

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>
2021-04-22 15:32:10 +02:00
Martí Bolívar
5332847644 dts: separate DT libraries from gen_defines.py
We are now in the process of extracting edtlib and dtlib into a
standalone source code library that we intend to share with other
projects.

Links related to the work making this standalone:

    https://pypi.org/project/devicetree/
    https://python-devicetree.readthedocs.io/en/latest/
    https://github.com/zephyrproject-rtos/python-devicetree

This standalone repo includes the same features as what we have in
Zephyr, but in its own 'devicetree' python package with PyPI
integration, etc.

To avoid making this a hard fork, move the code that's being made
standalone around in Zephyr into a new scripts/dts/python-devicetree
subdirectory, and handle the package and sys.path changes in the
various places in the tree that use it.

From now on, it will be possible to update the standalone repository
by just recursively copying scripts/dts/python-devicetree's contents
into it and committing the results.

This is an interim step; do NOT 'pip install devicetree' yet.
The code in the zephyr repository is still the canonical location.

(In the long term, people will get the devicetree package from PyPI
just like they do the 'yaml' package today, but that won't happen for
the foreseeable future.)

This commit is purely intended to avoid a hard fork for the standalone
code, and no functional changes besides the package structure and
location of the code itself are expected.

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>
2021-04-02 08:28:12 -05:00
Renamed from scripts/dts/testdtlib.py (Browse further)