binman: Add a null entry

It is sometimes useful to define an entry which does not have its own
contents but does appear in the image. The contents are set by the section
which contains it, even though it appears as an entry in the fdtmap.

Add support for this.

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

diff --git a/tools/binman/entries.rst b/tools/binman/entries.rst
index f6cc800385382103327acb9a1321dc87111fc1da..2b32c131ede4d23971b16ab0c7fbe496216fdbf1 100644 (file)
--- a/tools/binman/entries.rst
+++ b/tools/binman/entries.rst
@@ -1278,6 +1278,19 @@ This will pass in u-boot-spl as the input data and the .cfgout file as the
 
 
 
+.. _etype_null:
+
+Entry: null: An entry which has no contents of its own
+------------------------------------------------------
+
+Note that the size property must be set since otherwise this entry does not
+know how large it should be.
+
+The contents are set by the containing section, e.g. the section's pad
+byte.
+
+
+
 .. _etype_opensbi:
 
 Entry: opensbi: RISC-V OpenSBI fw_dynamic blob

diff --git a/tools/binman/entry.py b/tools/binman/entry.py
index f99618d4532339a05ad462b30aec7fb53dc40909..e6ff026ddb84a74c8ec9c010ebd3236d545996f9 100644 (file)
--- a/tools/binman/entry.py
+++ b/tools/binman/entry.py
@@ -454,7 +454,7 @@ class Entry(object):
 
         Returns:
             True if the contents were found, False if another call is needed
-            after the other entries are processed.
+            after the other entries are processed, None if there is no contents
         """
         # No contents by default: subclasses can implement this
         return True
@@ -583,7 +583,8 @@ class Entry(object):
         Returns:
             bytes content of the entry, excluding any padding. If the entry is
                 compressed, the compressed data is returned. If the entry data
-                is not yet available, False can be returned
+                is not yet available, False can be returned. If the entry data
+                is null, then None is returned.
         """
         self.Detail('GetData: size %s' % to_hex_size(self.data))
         return self.data

diff --git a/tools/binman/etype/null.py b/tools/binman/etype/null.py
new file mode 100644 (file)
index 0000000..c10d482
--- /dev/null
+++ b/tools/binman/etype/null.py
@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: GPL-2.0+
+# Copyright 2023 Google LLC
+# Written by Simon Glass <sjg@chromium.org>
+#
+
+from binman.entry import Entry
+from dtoc import fdt_util
+from patman import tools
+
+class Entry_null(Entry):
+    """An entry which has no contents of its own
+
+    Note that the size property must be set since otherwise this entry does not
+    know how large it should be.
+
+    The contents are set by the containing section, e.g. the section's pad
+    byte.
+    """
+    def __init__(self, section, etype, node):
+        super().__init__(section, etype, node)
+        self.required_props = ['size']
+
+    def ObtainContents(self):
+        # null contents
+        return None

diff --git a/tools/binman/etype/section.py b/tools/binman/etype/section.py
index 85474f2411e229518e901a3360e4222cc9ce4c68..28f04cb84a531a7184def15126205b16f0b75b37 100644 (file)
--- a/tools/binman/etype/section.py
+++ b/tools/binman/etype/section.py
@@ -320,6 +320,12 @@ class Entry_section(Entry):
             # earlier in the image description. See testCollectionSection().
             if not required and entry_data is None:
                 return None
+
+            if entry_data is None:
+                pad_byte = (entry._pad_byte if isinstance(entry, Entry_section)
+                            else self._pad_byte)
+                entry_data = tools.get_bytes(self._pad_byte, entry.size)
+
             data = self.GetPaddedDataForEntry(entry, entry_data)
             # Handle empty space before the entry
             pad = (entry.offset or 0) - self._skip_at_start - len(section_data)

diff --git a/tools/binman/ftest.py b/tools/binman/ftest.py
index a4f78ae041ac7f5a2337d88d0383cadb6edf16e4..ac9b050fb6caa474fa3c2384fd2e749952ba4aa1 100644 (file)
--- a/tools/binman/ftest.py
+++ b/tools/binman/ftest.py
@@ -6194,6 +6194,11 @@ fdt         fdtmap                Extract the devicetree blob from the fdtmap
         expected = U_BOOT_DATA + tools.get_bytes(0, 12)
         self.assertEqual(expected, data)
 
+    def testNull(self):
+        """Test an image with a null entry"""
+        data = self._DoReadFile('268_null.dts')
+        self.assertEqual(U_BOOT_DATA + b'\xff\xff\xff\xff' + U_BOOT_IMG_DATA, data)
+
 
 if __name__ == "__main__":
     unittest.main()

diff --git a/tools/binman/test/268_null.dts b/tools/binman/test/268_null.dts
new file mode 100644 (file)
index 0000000..3824ba8
--- /dev/null
+++ b/tools/binman/test/268_null.dts
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/dts-v1/;
+
+/ {
+       #address-cells = <1>;
+       #size-cells = <1>;
+
+       binman {
+               pad-byte = <0xff>;
+               u-boot {
+               };
+               null {
+                       size = <4>;
+               };
+               u-boot-img {
+               };
+       };
+};