From: Michael Brown <mcb30@ipxe.org>
Date: Mon, 26 Jul 2010 12:26:34 +0000 (+0100)
Subject: [tables] Add table_index()
X-Git-Tag: v1.20.1~2554
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=da123eada44c19a2b4efd2e095b3f90313dffd69;p=thirdparty%2Fipxe.git

[tables] Add table_index()

Signed-off-by: Michael Brown <mcb30@ipxe.org>
---

diff --git a/src/include/ipxe/tables.h b/src/include/ipxe/tables.h
index 130486c67..74d437537 100644
--- a/src/include/ipxe/tables.h
+++ b/src/include/ipxe/tables.h
@@ -308,6 +308,31 @@ FILE_LICENCE ( GPL2_OR_LATER );
 	( ( unsigned int ) ( table_end ( table ) -			\
 			     table_start ( table ) ) )
 
+/**
+ * Get index of entry within linker table
+ *
+ * @v table		Linker table
+ * @v entry		Table entry
+ *
+ * Example usage:
+ *
+ * @code
+ *
+ *   #define FROBNICATORS __table ( struct frobnicator, "frobnicators" )
+ *
+ *   #define __frobnicator __table_entry ( FROBNICATORS, 01 )
+ *
+ *   struct frobnicator my_frob __frobnicator = {
+ *      ...
+ *   };
+ *
+ *   unsigned int my_frob_idx = table_index ( FROBNICATORS, &my_frob );
+ *
+ * @endcode
+ */
+#define table_index( table, entry )					\
+	( ( unsigned int ) ( (entry) - table_start ( table ) ) )
+
 /**
  * Iterate through all entries within a linker table
  *