binman: Update state when replacing device-tree entries

Since the state module holds references to all the device trees used by
binman, it must be updated when the device trees are updated. Add support
for this.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/etype/blob_dtb.py b/tools/binman/etype/blob_dtb.py
index a3b548e..5b55996 100644
--- a/tools/binman/etype/blob_dtb.py
+++ b/tools/binman/etype/blob_dtb.py
@@ -53,3 +53,12 @@
         """
         fname = self.GetDefaultFilename()
         return {self.GetFdtEtype(): [self, fname]}
+
+    def WriteData(self, data, decomp=True):
+        ok = Entry_blob.WriteData(self, data, decomp)
+
+        # Update the state module, since it has the authoritative record of the
+        # device trees used. If we don't do this, then state.GetFdtContents()
+        # will still return the old contents
+        state.UpdateFdtContents(self.GetFdtEtype(), data)
+        return ok
diff --git a/tools/binman/state.py b/tools/binman/state.py
index f22cc82..d704ed2 100644
--- a/tools/binman/state.py
+++ b/tools/binman/state.py
@@ -108,6 +108,22 @@
         data = tools.ReadFile(pathname)
     return pathname, data
 
+def UpdateFdtContents(etype, data):
+    """Update the contents of a particular device tree
+
+    The device tree is updated and written back to its file. This affects what
+    is returned from future called to GetFdtContents(), etc.
+
+    Args:
+        etype: Entry type (e.g. 'u-boot-dtb')
+        data: Data to replace the DTB with
+    """
+    dtb, fname, entry = output_fdt_info[etype]
+    dtb_fname = dtb.GetFilename()
+    tools.WriteFile(dtb_fname, data)
+    dtb = fdt.FdtScan(dtb_fname)
+    output_fdt_info[etype] = [dtb, fname, entry]
+
 def SetEntryArgs(args):
     """Set the value of the entry args
 
diff --git a/tools/dtoc/fdt.py b/tools/dtoc/fdt.py
index cd7673c..6770be7 100644
--- a/tools/dtoc/fdt.py
+++ b/tools/dtoc/fdt.py
@@ -695,6 +695,14 @@
         node = Node(fdt, parent, offset, name, path)
         return node
 
+    def GetFilename(self):
+        """Get the filename of the device tree
+
+        Returns:
+            String filename
+        """
+        return self._fname
+
 def FdtScan(fname):
     """Returns a new Fdt object"""
     dtb = Fdt(fname)
diff --git a/tools/dtoc/test_fdt.py b/tools/dtoc/test_fdt.py
index 16a4430..028c8cb 100755
--- a/tools/dtoc/test_fdt.py
+++ b/tools/dtoc/test_fdt.py
@@ -449,6 +449,11 @@
         self.assertIn("node '/spl-test': Missing property 'one'",
                       str(e.exception))
 
+    def testGetFilename(self):
+        """Test the dtb filename can be provided"""
+        self.assertEqual(tools.GetOutputFilename('source.dtb'),
+                         self.dtb.GetFilename())
+
 
 class TestFdtUtil(unittest.TestCase):
     """Tests for the fdt_util module