binman: Provide general support for updating ELF symbols

The current support for updating variables in a binary is hard-coded to
work with U-Boot:

- It assumes the image starts at __image_copy_start
- It uses the existing U-Boot-specific entry types

It is useful for other projects to use these feature.

Add properties to enable writing symbols for any blob, a way of specifying
the base symbol and a way of providing the ELF filename to allow symbol
lookup to take place.

With this it is possible to update a Zephyr image, such as zephyr.bin
after it has been built.

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

1 files changed, 6 insertions, 0 deletions

diff --git a/tools/binman/etype/blob.py b/tools/binman/etype/blob.py
index 70dea7158e..c7ddcedffb 100644
--- a/tools/binman/etype/blob.py
+++ b/tools/binman/etype/blob.py
@@ -35,6 +35,12 @@ class Entry_blob(Entry):
         super().__init__(section, etype, node,
                          auto_write_symbols=auto_write_symbols)
         self._filename = fdt_util.GetString(self._node, 'filename', self.etype)
+        self.elf_fname = fdt_util.GetString(self._node, 'elf-filename',
+                                            self.elf_fname)
+        self.elf_base_sym = fdt_util.GetString(self._node, 'elf-base-sym')
+        if not self.auto_write_symbols:
+            if fdt_util.GetBool(self._node, 'write-symbols'):
+                self.auto_write_symbols = True
 
     def ObtainContents(self, fake_size=0):
         self._filename = self.GetDefaultFilename()