diff options
Diffstat (limited to 'doc/develop/driver-model')
| -rw-r--r-- | doc/develop/driver-model/livetree.rst | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/doc/develop/driver-model/livetree.rst b/doc/develop/driver-model/livetree.rst index 9f654f3b894..fb2969259d0 100644 --- a/doc/develop/driver-model/livetree.rst +++ b/doc/develop/driver-model/livetree.rst @@ -211,9 +211,18 @@ using it in new code. Modifying the livetree ---------------------- -This is not currently supported. Once implemented it should provide a much -more efficient implementation for modification of the device tree than using -the flat tree. +This is supported in a limited way, with ofnode_write_prop() and related +functions. + +The unflattening algorithm results in a single block of memory being +allocated for the whole tree. When writing new properties, these are +allocated new memory outside that block. When the block is freed, the +allocated properties remain. This can result in a memory leak. + +The solution to this leak would be to add a flag for properties (and nodes when +support is provided for adding those) that indicates that they should be +freed. Then the tree can be scanned for these 'separately allocated' nodes and +properties before freeing the memory block. Internal implementation @@ -281,6 +290,6 @@ Live tree support was introduced in U-Boot 2017.07. There is still quite a bit of work to do to flesh this out: - tests for all access functions -- support for livetree modification +- more support for livetree modification - addition of more access functions as needed - support for livetree in SPL and before relocation (if desired) |