Re: [PATCH v2 02/10] pylibfdt: Add subnode/property iterators and get_mem_rsv_list()

[David Gibson]

On Wed, Oct 28, 2026 at 02:46:51PM -0700, Douglas Anderson wrote:
> Add Pythonic iterator helpers on `FdtRo` to simplify walking nodes,
> properties, and memory reservation entries without manual offset loops
> or `-FDT_ERR_NOTFOUND` sentinel handling:
> 
> - `subnodes(nodeoffset)`: yields the offset of each direct child subnode
>   of `nodeoffset`.
> - `properties(nodeoffset)`: yields a `Property` object for each property
>   of `nodeoffset`.
> - `get_mem_rsv_list()`: returns a list of `(address, size)` tuples for
>   all entries in the memory reservation block.
> 
> Assisted-by: Gemini:gemini-pro-prerelease
> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>

Patches 1 & 2 are useful independent of the rest of the series.
Applied, thanks.

> ---
> 
> Changes in v2:
> - New patch adding FdtRo.subnodes(), FdtRo.properties(), and
>   FdtRo.get_mem_rsv_list()
> 
>  pylibfdt/libfdt.i       | 45 +++++++++++++++++++++++++++++++++++++++++
>  tests/pylibfdt_tests.py | 18 +++++++++++++++++
>  2 files changed, 63 insertions(+)
> 
> diff --git a/pylibfdt/libfdt.i b/pylibfdt/libfdt.i
> index 46f28f67290d..0db7110b4a38 100644
> --- a/pylibfdt/libfdt.i
> +++ b/pylibfdt/libfdt.i
> @@ -201,6 +201,23 @@ class FdtRo(object):
>          """
>          return check_err(fdt_next_subnode(self._fdt, nodeoffset), quiet)
>  
> +    def subnodes(self, nodeoffset):
> +        """Iterate over the subnodes of a node
> +
> +        Args:
> +            nodeoffset: Offset of parent node to check
> +
> +        Yields:
> +            Node offset of each direct subnode in order
> +
> +        Raises:
> +            FdtException on error (e.g. invalid nodeoffset)
> +        """
> +        soff = self.first_subnode(nodeoffset, quiet=QUIET_NOTFOUND)
> +        while soff >= 0:
> +            yield soff
> +            soff = self.next_subnode(soff, quiet=QUIET_NOTFOUND)
> +
>      def magic(self):
>          """Return the magic word from the header
>  
> @@ -302,6 +319,17 @@ class FdtRo(object):
>          check_err(val[0], quiet)
>          return val[1:]
>  
> +    def get_mem_rsv_list(self):
> +        """Return a list of all memory reserve-map records
> +
> +        Returns:
> +            List of (address, size) tuples for each memory reserve-map record
> +        """
> +        return [
> +            tuple(self.get_mem_rsv(i))
> +            for i in range(self.num_mem_rsv())
> +        ]
> +
>      def address_cells(self, nodeoffset, quiet=()):
>          """Return the number of address cells used by a node's children
>  
> @@ -434,6 +462,23 @@ class FdtRo(object):
>              return pdata[1]
>          return Property(pdata[0], pdata[1])
>  
> +    def properties(self, nodeoffset):
> +        """Iterate over the properties of a node
> +
> +        Args:
> +            nodeoffset: Offset of node to check
> +
> +        Yields:
> +            Property object for each property on @nodeoffset in order
> +
> +        Raises:
> +            FdtException on error (e.g. invalid nodeoffset)
> +        """
> +        poff = self.first_property_offset(nodeoffset, quiet=QUIET_NOTFOUND)
> +        while poff >= 0:
> +            yield self.get_property_by_offset(poff)
> +            poff = self.next_property_offset(poff, quiet=QUIET_NOTFOUND)
> +
>      def getprop(self, nodeoffset, prop_name, quiet=()):
>          """Get a property from a node
>  
> diff --git a/tests/pylibfdt_tests.py b/tests/pylibfdt_tests.py
> index 1b65961491bf..2a0509c7802e 100644
> --- a/tests/pylibfdt_tests.py
> +++ b/tests/pylibfdt_tests.py
> @@ -243,6 +243,22 @@ class PyLibfdtBasicTests(unittest.TestCase):
>              node_list.append(self.fdt.get_name(node))
>              node = self.fdt.next_subnode(node, QUIET_NOTFOUND)
>          self.assertEqual(node_list, ['subnode@1', 'subnode@2'])
> +        self.assertEqual(
> +            [self.fdt.get_name(n) for n in self.fdt.subnodes(0)],
> +            ['subnode@1', 'subnode@2'],
> +        )
> +        leaf = self.fdt.path_offset('/subnode@1/ss1')
> +        self.assertEqual(list(self.fdt.subnodes(leaf)), [])
> +
> +    def testPropertiesIterator(self):
> +        """Check that we can iterate through properties of a node"""
> +        node = self.fdt.path_offset('/subnode@1')
> +        props = list(self.fdt.properties(node))
> +        self.assertEqual([p.name for p in props],
> +                         ['compatible', 'reg', 'prop-int'])
> +        self.assertEqual(props[0], b'subnode1\0')
> +        leaf = self.fdt.path_offset('/subnode@1/ss1')
> +        self.assertEqual(list(self.fdt.properties(leaf)), [])
>  
>      def testFirstNextSubnodeOffsetExceptions(self):
>          """Check except handling for first/next subnode functions"""
> @@ -410,6 +426,8 @@ class PyLibfdtBasicTests(unittest.TestCase):
>          self.assertEqual([ 0xdeadbeef00000000, 0x100000],
>                            self.fdt.get_mem_rsv(0))
>          self.assertEqual([123456789, 0o10000], self.fdt.get_mem_rsv(1))
> +        self.assertEqual([(0xdeadbeef00000000, 0x100000), (123456789, 0o10000)],
> +                         self.fdt.get_mem_rsv_list())
>  
>      def testAddDelReserveMap(self):
>          """Test that we can add to and remove from the memory reserve map"""
> -- 
> 2.56.0.313.g2479322e68-goog
> 
> 

-- 
David Gibson (he or they)	| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you, not the other way
				| around.
http://www.ozlabs.org/~dgibson

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