e2addr(): New macro.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@689 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/drv/eeprom.h b/drv/eeprom.h
index c41519d7244cc0427c5c6394d8d8cb0a2c7762d7..7a80f177976f5c825677d9dc98dd5e7a9e28f5d5 100755 (executable)
--- a/drv/eeprom.h
+++ b/drv/eeprom.h
@@ -15,6 +15,9 @@
 
 /*#*
  *#* $Log$
+ *#* Revision 1.10  2006/09/13 18:29:54  bernie
+ *#* e2addr(): New macro.
+ *#*
  *#* Revision 1.9  2006/07/19 12:56:25  bernie
  *#* Convert to new Doxygen style.
  *#*
@@ -70,6 +73,17 @@
 /// Type for EEPROM addresses
 typedef uint16_t e2addr_t;
 
+/**
+ * Macro for E2Layout offset calculation
+ *
+ * \note We can't just use offsetof() here because we could use
+ *       non-constant expressions to access array elements.
+ *
+ * \note E2Layout is a structure that must be defined in user files.
+ */
+#define e2addr(x) ((e2addr_t)&(((struct E2Layout *)0)->x))
+
+
 bool eeprom_write(e2addr_t addr, const void *buf, size_t count);
 bool eeprom_read(e2addr_t addr, void *buf, size_t count);
 bool eeprom_write_char(e2addr_t addr, char c);