new cache_as_ram support

git-svn-id: svn://svn.coreboot.org/coreboot/trunk@2232 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

src/include/cpu/x86/mem.h

@@ -4,15 +4,13 @@
 /* Optimized generic x86 assembly for clearing memory */
 static inline void clear_memory(void *addr, unsigned long size)
 {
-	asm volatile(
-		"1: \n\t"
-		"movl %0, (%1)\n\t"
-		"addl $4, %1\n\t"
-		"subl $4, %2\n\t"
-		"jnz 1b\n\t"
-		: /* No outputs */
-		: "a" (0), "D" (addr), "c" (size)
-		);
+        asm volatile(
+                "cld \n\t"
+                "rep stosl\n\t"
+                : /* No outputs */
+                : "a" (0), "D" (addr), "c" (size>>2)
+                );
+
 }
 
 #endif /* CPU_X86_MEM_H */