binman: Add more tests for image header position

The positioning does not currently work correctly if at the end of an
image with no fixed size. Also if the header is in the middle of an image
it can cause a gap in the image since the header position is normally at
the image end, so entries after it are placed after the end of the image.

Fix these problems and add more tests to cover these cases.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/entry.py b/tools/binman/entry.py
index 74e2808..8dacc61 100644
--- a/tools/binman/entry.py
+++ b/tools/binman/entry.py
@@ -745,3 +745,18 @@
         ok = self.ProcessContentsUpdate(data)
         self.Detail('WriteData: size=%x, ok=%s' % (len(data), ok))
         return ok
+
+    def GetSiblingOrder(self):
+        """Get the relative order of an entry amoung its siblings
+
+        Returns:
+            'start' if this entry is first among siblings, 'end' if last,
+                otherwise None
+        """
+        entries = list(self.section.GetEntries().values())
+        if entries:
+            if self == entries[0]:
+                return 'start'
+            elif self == entries[-1]:
+                return 'end'
+        return 'middle'
diff --git a/tools/binman/etype/image_header.py b/tools/binman/etype/image_header.py
index 8f9c5aa..4b69eda 100644
--- a/tools/binman/etype/image_header.py
+++ b/tools/binman/etype/image_header.py
@@ -86,8 +86,20 @@
             if self.location not in ['start', 'end']:
                 self.Raise("Invalid location '%s', expected 'start' or 'end'" %
                            self.location)
-            image_size = self.section.GetImageSize() or 0
-            self.offset = (0 if self.location != 'end' else image_size - 8)
+            order = self.GetSiblingOrder()
+            if self.location != order and not self.section.GetSort():
+                self.Raise("Invalid sibling order '%s' for image-header: Must be at '%s' to match location" %
+                           (order, self.location))
+            if self.location != 'end':
+                offset = 0
+            else:
+                image_size = self.section.GetImageSize()
+                if image_size is None:
+                    # We don't know the image, but this must be the last entry,
+                    # so we can assume it goes
+                    offset = offset
+                else:
+                    offset = image_size - IMAGE_HEADER_LEN
         return Entry.Pack(self, offset)
 
     def ProcessContents(self):
diff --git a/tools/binman/etype/section.py b/tools/binman/etype/section.py
index 0fb8141..3ce013d 100644
--- a/tools/binman/etype/section.py
+++ b/tools/binman/etype/section.py
@@ -479,3 +479,12 @@
         if not self.section:
             return self
         return self.section.GetImage()
+
+    def GetSort(self):
+        """Check if the entries in this section will be sorted
+
+        Returns:
+            True if to be sorted, False if entries will be left in the order
+                they appear in the device tree
+        """
+        return self._sort
diff --git a/tools/binman/ftest.py b/tools/binman/ftest.py
index b67e8a1..bc75189 100644
--- a/tools/binman/ftest.py
+++ b/tools/binman/ftest.py
@@ -2886,6 +2886,31 @@
             else:
                 start += dtb._fdt_obj.totalsize()
 
+    def testFdtmapHeaderMiddle(self):
+        """Test an FDT map in the middle of an image when it should be at end"""
+        with self.assertRaises(ValueError) as e:
+            self._DoReadFileRealDtb('135_fdtmap_hdr_middle.dts')
+        self.assertIn("Invalid sibling order 'middle' for image-header: Must be at 'end' to match location",
+                      str(e.exception))
+
+    def testFdtmapHeaderStartBad(self):
+        """Test an FDT map in middle of an image when it should be at start"""
+        with self.assertRaises(ValueError) as e:
+            self._DoReadFileRealDtb('136_fdtmap_hdr_startbad.dts')
+        self.assertIn("Invalid sibling order 'end' for image-header: Must be at 'start' to match location",
+                      str(e.exception))
+
+    def testFdtmapHeaderEndBad(self):
+        """Test an FDT map at the start of an image when it should be at end"""
+        with self.assertRaises(ValueError) as e:
+            self._DoReadFileRealDtb('137_fdtmap_hdr_endbad.dts')
+        self.assertIn("Invalid sibling order 'start' for image-header: Must be at 'end' to match location",
+                      str(e.exception))
+
+    def testFdtmapHeaderNoSize(self):
+        """Test an image header at the end of an image with undefined size"""
+        self._DoReadFileRealDtb('138_fdtmap_hdr_nosize.dts')
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/tools/binman/test/135_fdtmap_hdr_middle.dts b/tools/binman/test/135_fdtmap_hdr_middle.dts
new file mode 100644
index 0000000..d6211da
--- /dev/null
+++ b/tools/binman/test/135_fdtmap_hdr_middle.dts
@@ -0,0 +1,16 @@
+/dts-v1/;
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	binman {
+		u-boot {
+		};
+		image-header {
+			location = "end";
+		};
+		fdtmap {
+		};
+	};
+};
diff --git a/tools/binman/test/136_fdtmap_hdr_startbad.dts b/tools/binman/test/136_fdtmap_hdr_startbad.dts
new file mode 100644
index 0000000..ec5f4bc
--- /dev/null
+++ b/tools/binman/test/136_fdtmap_hdr_startbad.dts
@@ -0,0 +1,16 @@
+/dts-v1/;
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	binman {
+		u-boot {
+		};
+		fdtmap {
+		};
+		image-header {
+			location = "start";
+		};
+	};
+};
diff --git a/tools/binman/test/137_fdtmap_hdr_endbad.dts b/tools/binman/test/137_fdtmap_hdr_endbad.dts
new file mode 100644
index 0000000..ebacd71
--- /dev/null
+++ b/tools/binman/test/137_fdtmap_hdr_endbad.dts
@@ -0,0 +1,16 @@
+/dts-v1/;
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	binman {
+		image-header {
+			location = "end";
+		};
+		u-boot {
+		};
+		fdtmap {
+		};
+	};
+};
diff --git a/tools/binman/test/138_fdtmap_hdr_nosize.dts b/tools/binman/test/138_fdtmap_hdr_nosize.dts
new file mode 100644
index 0000000..c362f8f
--- /dev/null
+++ b/tools/binman/test/138_fdtmap_hdr_nosize.dts
@@ -0,0 +1,16 @@
+/dts-v1/;
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	binman {
+		u-boot {
+		};
+		fdtmap {
+		};
+		image-header {
+			location = "end";
+		};
+	};
+};