dtoc: Support packing the device tree
After any node/property deletion the device tree can be packed to remove
spare space. Add a way to perform this operation.
Note that for fdt_fallback, fdtput automatically packs the device tree after
deletion, so no action is required here.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/libfdt/libfdt.swig b/lib/libfdt/libfdt.swig
index ce516fd..0cb7977 100644
--- a/lib/libfdt/libfdt.swig
+++ b/lib/libfdt/libfdt.swig
@@ -107,3 +107,4 @@
int fdt_delprop(void *fdt, int nodeoffset, const char *name);
const char *fdt_strerror(int errval);
+int fdt_pack(void *fdt);
diff --git a/tools/dtoc/fdt.py b/tools/dtoc/fdt.py
index f01c7b1..403eb1f 100644
--- a/tools/dtoc/fdt.py
+++ b/tools/dtoc/fdt.py
@@ -240,3 +240,19 @@
return None
return node
+ def Flush(self):
+ """Flush device tree changes back to the file
+
+ If the device tree has changed in memory, write it back to the file.
+ Subclasses can implement this if needed.
+ """
+ pass
+
+ def Pack(self):
+ """Pack the device tree down to its minimum size
+
+ When nodes and properties shrink or are deleted, wasted space can
+ build up in the device tree binary. Subclasses can implement this
+ to remove that spare space.
+ """
+ pass
diff --git a/tools/dtoc/fdt_normal.py b/tools/dtoc/fdt_normal.py
index 52d8055..f2cf608 100644
--- a/tools/dtoc/fdt_normal.py
+++ b/tools/dtoc/fdt_normal.py
@@ -140,6 +140,17 @@
"""
return self._fdt
+ def Flush(self):
+ """Flush device tree changes back to the file"""
+ with open(self._fname, 'wb') as fd:
+ fd.write(self._fdt)
+
+ def Pack(self):
+ """Pack the device tree down to its minimum size"""
+ CheckErr(libfdt.fdt_pack(self._fdt), 'pack')
+ fdt_len = libfdt.fdt_totalsize(self._fdt)
+ del self._fdt[fdt_len:]
+
def GetProps(self, node, path):
"""Get all properties from a node.