binman: Respect pad-before property of section subentries

Other relevant properties (pad-after, offset, size, align, align-size,
align-end) already work since Pack() sets correct ranges for subentries'
data (.offset, .size variables), but some padding here is necessary to
align the data within this range to match the pad-before property.

Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

tools/binman/etype/section.py

@@ -152,7 +152,7 @@ class Entry_section(Entry):
         for entry in self._entries.values():
             data = entry.GetData()
             base = self.pad_before + (entry.offset or 0) - self._skip_at_start
-            pad = base - len(section_data)
+            pad = base - len(section_data) + (entry.pad_before or 0)
             if pad > 0:
                 section_data += tools.GetBytes(self._pad_byte, pad)
             section_data += data

tools/binman/ftest.py

@@ -3483,5 +3483,13 @@ class TestFunctional(unittest.TestCase):
         expected = (U_BOOT_DATA + U_BOOT_DATA)
         self.assertEqual(expected, data)
 
+    def testPadInSections(self):
+        """Test pad-before, pad-after for entries in sections"""
+        data = self._DoReadFile('166_pad_in_sections.dts')
+        expected = (U_BOOT_DATA + tools.GetBytes(ord('!'), 12) +
+                    U_BOOT_DATA + tools.GetBytes(ord('!'), 6) +
+                    U_BOOT_DATA)
+        self.assertEqual(expected, data)
+
 if __name__ == "__main__":
     unittest.main()

tools/binman/test/166_pad_in_sections.dts

@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/dts-v1/;
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	binman {
+		pad-byte = <0x26>;
+		section {
+			pad-byte = <0x21>;
+
+			before {
+				type = "u-boot";
+			};
+			u-boot {
+				pad-before = <12>;
+				pad-after = <6>;
+			};
+			after {
+				type = "u-boot";
+			};
+		};
+	};
+};