binman: Update elf to return number of written symbols

Update the LookupAndWriteSymbols() function to return the number of
symbols written. Also add some logging for when debugging is not
enabled.

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

tools/binman/elf.py

@@ -248,6 +248,9 @@ def LookupAndWriteSymbols(elf_fname, entry, section, is_elf=False,
         entry: Entry to process
         section: Section which can be used to lookup symbol values
         base_sym: Base symbol marking the start of the image
+
+    Returns:
+        int: Number of symbols written
     """
     if not base_sym:
         base_sym = '__image_copy_start'
@@ -269,12 +272,13 @@ def LookupAndWriteSymbols(elf_fname, entry, section, is_elf=False,
 
     if not syms:
         tout.debug('LookupAndWriteSymbols: no syms')
-        return
+        return 0
     base = syms.get(base_sym)
     if not base and not is_elf:
         tout.debug('LookupAndWriteSymbols: no base')
-        return
+        return 0
     base_addr = 0 if is_elf else base.address
+    count = 0
     for name, sym in syms.items():
         if name.startswith('_binman'):
             msg = ("Section '%s': Symbol '%s'\n   in entry '%s'" %
@@ -307,6 +311,11 @@ def LookupAndWriteSymbols(elf_fname, entry, section, is_elf=False,
                        (msg, name, offset, value, len(value_bytes)))
             entry.data = (entry.data[:offset] + value_bytes +
                         entry.data[offset + sym.size:])
+            count += 1
+    if count:
+        tout.detail(
+            f"Section '{section.GetPath()}': entry '{entry.GetPath()}' : {count} symbols")
+    return count
 
 def GetSymbolValue(sym, data, msg):
     """Get the value of a symbol

tools/binman/elf_test.py

@@ -141,7 +141,8 @@ class TestElf(unittest.TestCase):
         entry = FakeEntry(10)
         section = FakeSection()
         elf_fname = self.ElfTestFile('u_boot_binman_syms_bad')
-        elf.LookupAndWriteSymbols(elf_fname, entry, section)
+        count = elf.LookupAndWriteSymbols(elf_fname, entry, section)
+        self.assertEqual(0, count)
 
     def testBadSymbolSize(self):
         """Test that an attempt to use an 8-bit symbol are detected
@@ -162,7 +163,7 @@ class TestElf(unittest.TestCase):
     def testNoValue(self):
         """Test the case where we have no value for the symbol
 
-        This should produce -1 values for all thress symbols, taking up the
+        This should produce -1 values for all three symbols, taking up the
         first 16 bytes of the image.
         """
         if not elf.ELF_TOOLS:
@@ -170,7 +171,8 @@ class TestElf(unittest.TestCase):
         entry = FakeEntry(28)
         section = FakeSection(sym_value=None)
         elf_fname = self.ElfTestFile('u_boot_binman_syms')
-        elf.LookupAndWriteSymbols(elf_fname, entry, section)
+        count = elf.LookupAndWriteSymbols(elf_fname, entry, section)
+        self.assertEqual(5, count)
         expected = (struct.pack('<L', elf.BINMAN_SYM_MAGIC_VALUE) +
                     tools.get_bytes(255, 20) +
                     tools.get_bytes(ord('a'), 4))