Implement MmZeroPages() routine

xtoskrnl/mm/i686/pages.c

@@ -0,0 +1,38 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            xtoskrnl/mm/i686/pages.c
+ * DESCRIPTION:     Architecture dependent paging support
+ * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
+ */
+
+#include <xtos.h>
+
+
+/**
+ * Fills a section of memory with zeroes like RtlZeroMemory(), but in more efficient way.
+ *
+ * @param Address
+ *        Supplies an address of the page to be filled with zeroes.
+ *
+ * @param Size
+ *        Number of bytes to be filled with zeros. This always should be a multiply of page size.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+XTFASTCALL
+VOID
+MmZeroPages(IN PVOID Address,
+            IN ULONG Size)
+{
+    asm volatile("xor %%eax, %%eax\n"
+                 "rep stosb"
+                 : "=D"(Address),
+                   "=c"(Size)
+                 : "0"(Address),
+                   "1"(Size),
+                   "a"(0)
+                 : "memory");
+}