Add symbol- and bytescan- based location lookup for signature

src/smgdc/validate.py

@@ -69,7 +69,12 @@ class BaseBinary:
     def mmap(self):
         mm = mmap.mmap(self._file.fileno(), 0, access=mmap.ACCESS_READ)
         yield mm
-        mm.close()
+
+        # FIXME: We currently don't close this because an error gets thrown at
+        #        ``LocationEntry.calculate_phys_address()`` due to exported pointers.  It's not
+        #        clear to me if the issue stems from ``ByteSignature.expr.finditer()`` or
+        #        something else at this point.
+        # mm.close()
 
     def read(self, address, size) -> bytes:
         # shorthand to read a value from a physical file
@@ -211,6 +216,18 @@ class ByteSigEntry(LocationEntry, tag="bytesig", kw_only=True):
     allow_multiple: bool = False
 
     def process(self, bin: PlatformBinary) -> ResultValues:
+        if self.symbol or self.bytescan:
+            address = self.calculate_phys_address(bin)
+            data = bin.read(address, self.contents.length)
+            if not self.contents.expr.match(data):
+                actual_disp = f"[{data.hex(' ')}]"
+                raise AssertionError(
+                    f"Assertion failed: {self.contents.display_str} != {actual_disp}"
+                )
+            return {
+                KEY_AS_IS: self.contents.gameconf_str,
+            }
+
         with bin.mmap() as memory:
             matches = self.contents.expr.finditer(memory)
             match = next(matches, False)