binman: Allow device-tree entries to be compressed

At present the logic skips the blob class' handling of compression, so
this is not supported with device tree entries. Fix this.

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/binman/etype/blob.py

@@ -41,17 +41,26 @@ class Entry_blob(Entry):
         self.ReadBlobContents()
         return True
 
-    def ReadBlobContents(self):
-        # We assume the data is small enough to fit into memory. If this
-        # is used for large filesystem image that might not be true.
-        # In that case, Image.BuildImage() could be adjusted to use a
-        # new Entry method which can read in chunks. Then we could copy
-        # the data in chunks and avoid reading it all at once. For now
-        # this seems like an unnecessary complication.
-        indata = tools.ReadFile(self._pathname)
+    def CompressData(self, indata):
         if self.compress != 'none':
             self.uncomp_size = len(indata)
         data = tools.Compress(indata, self.compress)
+        return data
+
+    def ReadBlobContents(self):
+        """Read blob contents into memory
+
+        This function compresses the data before storing if needed.
+
+        We assume the data is small enough to fit into memory. If this
+        is used for large filesystem image that might not be true.
+        In that case, Image.BuildImage() could be adjusted to use a
+        new Entry method which can read in chunks. Then we could copy
+        the data in chunks and avoid reading it all at once. For now
+        this seems like an unnecessary complication.
+        """
+        indata = tools.ReadFile(self._pathname)
+        data = self.CompressData(indata)
         self.SetContents(data)
         return True
 

tools/binman/etype/blob_dtb.py

@@ -23,11 +23,11 @@ class Entry_blob_dtb(Entry_blob):
     def ObtainContents(self):
         """Get the device-tree from the list held by the 'state' module"""
         self._filename = self.GetDefaultFilename()
-        self._pathname, data = state.GetFdtContents(self._filename)
-        self.SetContents(data)
-        return True
+        self._pathname, _ = state.GetFdtContents(self._filename)
+        return Entry_blob.ReadBlobContents(self)
 
     def ProcessContents(self):
         """Re-read the DTB contents so that we get any calculated properties"""
-        _, data = state.GetFdtContents(self._filename)
+        _, indata = state.GetFdtContents(self._filename)
+        data = self.CompressData(indata)
         return self.ProcessContentsUpdate(data)

tools/binman/ftest.py

@@ -2142,6 +2142,24 @@ class TestFunctional(unittest.TestCase):
         self.assertEqual(U_BOOT_DATA, data[2:2 + len(U_BOOT_DATA)])
         self.assertEqual(b'aa', data[-2:])
 
+    def testCompressDtb(self):
+        """Test that compress of device-tree files is supported"""
+        self._CheckLz4()
+        data = self.data = self._DoReadFileRealDtb('124_compress_dtb.dts')
+        self.assertEqual(U_BOOT_DATA, data[:len(U_BOOT_DATA)])
+        comp_data = data[len(U_BOOT_DATA):]
+        orig = self._decompress(comp_data)
+        dtb = fdt.Fdt.FromData(orig)
+        dtb.Scan()
+        props = self._GetPropTree(dtb, ['size', 'uncomp-size'])
+        expected = {
+            'u-boot:size': len(U_BOOT_DATA),
+            'u-boot-dtb:uncomp-size': len(orig),
+            'u-boot-dtb:size': len(comp_data),
+            'size': len(data),
+            }
+        self.assertEqual(expected, props)
+
 
 if __name__ == "__main__":
     unittest.main()

tools/binman/test/124_compress_dtb.dts

@@ -0,0 +1,14 @@
+/dts-v1/;
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	binman {
+		u-boot {
+		};
+		u-boot-dtb {
+			compress = "lz4";
+		};
+	};
+};