diff options
Diffstat (limited to 'tools/dtoc/fdt.py')
| -rw-r--r-- | tools/dtoc/fdt.py | 44 |
1 files changed, 35 insertions, 9 deletions
diff --git a/tools/dtoc/fdt.py b/tools/dtoc/fdt.py index a5e1d0b52f..63d1f68d81 100644 --- a/tools/dtoc/fdt.py +++ b/tools/dtoc/fdt.py @@ -503,9 +503,13 @@ class Node: auto_resize: Resize the device tree automatically if it does not have enough space for the update + Returns: + True if the node had to be added, False if it already existed + Raises: FdtException if auto_resize is False and there is not enough space """ + added = False if self._offset is None: # The subnode doesn't exist yet, so add it fdt_obj = self._fdt._fdt_obj @@ -519,23 +523,45 @@ class Node: else: offset = fdt_obj.add_subnode(self.parent._offset, self.name) self._offset = offset + added = True - # Sync subnodes in reverse so that we don't disturb node offsets for - # nodes that are earlier in the DT. This avoids an O(n^2) rescan of - # node offsets. + # Sync the existing subnodes first, so that we can rely on the offsets + # being correct. As soon as we add new subnodes, it pushes all the + # existing subnodes up. for node in reversed(self.subnodes): - node.Sync(auto_resize) + if node._offset is not None: + node.Sync(auto_resize) - # Sync properties now, whose offsets should not have been disturbed. - # We do this after subnodes, since this disturbs the offsets of these - # properties. Note that new properties will have an offset of None here, - # which Python 3 cannot sort against int. So use a large value instead - # to ensure that the new properties are added first. + # Sync subnodes in reverse so that we get the expected order. Each + # new node goes at the start of the subnode list. This avoids an O(n^2) + # rescan of node offsets. + num_added = 0 + for node in reversed(self.subnodes): + if node.Sync(auto_resize): + num_added += 1 + if num_added: + # Reorder our list of nodes to put the new ones first, since that's + # what libfdt does + old_count = len(self.subnodes) - num_added + subnodes = self.subnodes[old_count:] + self.subnodes[:old_count] + self.subnodes = subnodes + + # Sync properties now, whose offsets should not have been disturbed, + # since properties come before subnodes. This is done after all the + # subnode processing above, since updating properties can disturb the + # offsets of those subnodes. + # Properties are synced in reverse order, with new properties added + # before existing properties are synced. This ensures that the offsets + # of earlier properties are not disturbed. + # Note that new properties will have an offset of None here, which + # Python cannot sort against int. So use a large value instead so that + # new properties are added first. prop_list = sorted(self.props.values(), key=lambda prop: prop._offset or 1 << 31, reverse=True) for prop in prop_list: prop.Sync(auto_resize) + return added class Fdt: |