+ u32 unused; /* reserved for future expansion: MUST be 0 */
+
+ /* operating system version and security patch level; for
+ * version "A.B.C" and patch level "Y-M-D":
+ * ver = A << 14 | B << 7 | C (7 bits for each of A, B, C)
+ * lvl = ((Y - 2000) & 127) << 4 | M (7 bits for Y, 4 bits for M)
+ * os_version = ver << 11 | lvl */
+ u32 os_version;