binman: Allow selecting default FIT configuration

Add a new entry argument to the fit entry which allows selection of the
default configuration to use. This is the 'default' property in the
'configurations' node.

Update the Makefile to pass in the value of DEVICE_TREE or
CONFIG_DEFAULT_DEVICE_TREE to provide this information.

Signed-off-by: Simon Glass <sjg@chromium.org>
Suggested-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/Makefile b/Makefile
index 07cd28f..2de0527 100644
--- a/Makefile
+++ b/Makefile
@@ -1321,6 +1321,7 @@
 # binman
 # ---------------------------------------------------------------------------
 # Use 'make BINMAN_DEBUG=1' to enable debugging
+default_dt := $(if $(DEVICE_TREE),$(DEVICE_TREE),$(CONFIG_DEFAULT_DEVICE_TREE))
 quiet_cmd_binman = BINMAN  $@
 cmd_binman = $(srctree)/tools/binman/binman $(if $(BINMAN_DEBUG),-D) \
                 --toolpath $(objtree)/tools \
@@ -1329,6 +1330,7 @@
 		-I . -I $(srctree) -I $(srctree)/board/$(BOARDDIR) \
 		-I arch/$(ARCH)/dts -a of-list=$(CONFIG_OF_LIST) \
 		-a atf-bl31-path=${BL31} \
+		-a default-dt=$(default_dt) \
 		$(BINMAN_$(@F))
 
 OBJCOPYFLAGS_u-boot.ldr.hex := -I binary -O ihex
diff --git a/tools/binman/README.entries b/tools/binman/README.entries
index d2628df..c1d4365 100644
--- a/tools/binman/README.entries
+++ b/tools/binman/README.entries
@@ -402,6 +402,10 @@
 Note that if no devicetree files are provided (with '-a of-list' as above)
 then no nodes will be generated.
 
+The 'default' property, if present, will be automatically set to the name
+if of configuration whose devicetree matches the 'default-dt' entry
+argument, e.g. with '-a default-dt=sun50i-a64-pine64-lts'.
+
 
 Properties (in the 'fit' node itself):
     fit,external-offset: Indicates that the contents of the FIT are external
diff --git a/tools/binman/etype/fit.py b/tools/binman/etype/fit.py
index c291eb2..de4745c 100644
--- a/tools/binman/etype/fit.py
+++ b/tools/binman/etype/fit.py
@@ -90,6 +90,14 @@
     Note that if no devicetree files are provided (with '-a of-list' as above)
     then no nodes will be generated.
 
+    The 'default' property, if present, will be automatically set to the name
+    if of configuration whose devicetree matches the 'default-dt' entry
+    argument, e.g. with '-a default-dt=sun50i-a64-pine64-lts'.
+
+    Available substitutions for '@' property values are:
+
+        DEFAULT-SEQ  Sequence number of the default fdt,as provided by the
+                     'default-dt' entry argument
 
     Properties (in the 'fit' node itself):
         fit,external-offset: Indicates that the contents of the FIT are external
@@ -121,6 +129,8 @@
                 [EntryArg(self._fit_list_prop.value, str)])
             if fdts is not None:
                 self._fdts = fdts.split()
+        self._fit_default_dt = self.GetEntryArgsOrProps([EntryArg('default-dt',
+                                                                  str)])[0]
 
     def ReadNode(self):
         self._ReadSubnodes()
@@ -142,6 +152,22 @@
             """
             for pname, prop in node.props.items():
                 if not pname.startswith('fit,'):
+                    if pname == 'default':
+                        val = prop.value
+                        # Handle the 'default' property
+                        if val.startswith('@'):
+                            if not self._fdts:
+                                continue
+                            if not self._fit_default_dt:
+                                self.Raise("Generated 'default' node requires default-dt entry argument")
+                            if self._fit_default_dt not in self._fdts:
+                                self.Raise("default-dt entry argument '%s' not found in fdt list: %s" %
+                                           (self._fit_default_dt,
+                                            ', '.join(self._fdts)))
+                            seq = self._fdts.index(self._fit_default_dt)
+                            val = val[1:].replace('DEFAULT-SEQ', str(seq + 1))
+                            fsw.property_string(pname, val)
+                            continue
                     fsw.property(pname, prop.bytes)
 
             rel_path = node.path[len(base_node.path):]
diff --git a/tools/binman/ftest.py b/tools/binman/ftest.py
index 78d0e9c..a269a74 100644
--- a/tools/binman/ftest.py
+++ b/tools/binman/ftest.py
@@ -3602,7 +3602,7 @@
             """
             cnode = dtb.GetNode('/configurations')
             self.assertIn('default', cnode.props)
-            self.assertEqual('config-1', cnode.props['default'].value)
+            self.assertEqual('config-2', cnode.props['default'].value)
 
             name = 'config-%d' % seq
             fnode = dtb.GetNode('/configurations/%s' % name)
@@ -3615,9 +3615,10 @@
 
         entry_args = {
             'of-list': 'test-fdt1 test-fdt2',
+            'default-dt': 'test-fdt2',
         }
         data = self._DoReadFileDtb(
-            '170_fit_fdt.dts',
+            '172_fit_fdt.dts',
             entry_args=entry_args,
             extra_indirs=[os.path.join(self._indir, TEST_FDT_SUBDIR)])[0]
         self.assertEqual(U_BOOT_NODTB_DATA, data[-len(U_BOOT_NODTB_DATA):])
@@ -3639,7 +3640,7 @@
     def testFitFdtMissingList(self):
         """Test handling of a missing 'of-list' entry arg"""
         with self.assertRaises(ValueError) as e:
-            self._DoReadFile('170_fit_fdt.dts')
+            self._DoReadFile('172_fit_fdt.dts')
         self.assertIn("Generator node requires 'of-list' entry argument",
                       str(e.exception))
 
@@ -3657,5 +3658,39 @@
         self.assertIn("Generator node requires 'fit,fdt-list' property",
                       str(e.exception))
 
+    def testFitFdtEmptyList(self):
+        """Test handling of an empty 'of-list' entry arg"""
+        entry_args = {
+            'of-list': '',
+        }
+        data = self._DoReadFileDtb('172_fit_fdt.dts', entry_args=entry_args)[0]
+
+    def testFitFdtMissing(self):
+        """Test handling of a missing 'default-dt' entry arg"""
+        entry_args = {
+            'of-list': 'test-fdt1 test-fdt2',
+        }
+        with self.assertRaises(ValueError) as e:
+            self._DoReadFileDtb(
+                '172_fit_fdt.dts',
+                entry_args=entry_args,
+                extra_indirs=[os.path.join(self._indir, TEST_FDT_SUBDIR)])[0]
+        self.assertIn("Generated 'default' node requires default-dt entry argument",
+                      str(e.exception))
+
+    def testFitFdtNotInList(self):
+        """Test handling of a default-dt that is not in the of-list"""
+        entry_args = {
+            'of-list': 'test-fdt1 test-fdt2',
+            'default-dt': 'test-fdt3',
+        }
+        with self.assertRaises(ValueError) as e:
+            self._DoReadFileDtb(
+                '172_fit_fdt.dts',
+                entry_args=entry_args,
+                extra_indirs=[os.path.join(self._indir, TEST_FDT_SUBDIR)])[0]
+        self.assertIn("default-dt entry argument 'test-fdt3' not found in fdt list: test-fdt1, test-fdt2",
+                      str(e.exception))
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/tools/binman/test/170_fit_fdt.dts b/tools/binman/test/172_fit_fdt.dts
similarity index 95%
rename from tools/binman/test/170_fit_fdt.dts
rename to tools/binman/test/172_fit_fdt.dts
index 89142e9..99d710c 100644
--- a/tools/binman/test/170_fit_fdt.dts
+++ b/tools/binman/test/172_fit_fdt.dts
@@ -40,7 +40,7 @@
 			};
 
 			configurations {
-				default = "config-1";
+				default = "@config-DEFAULT-SEQ";
 				@config-SEQ {
 					description = "conf-NAME.dtb";
 					firmware = "uboot";