Migrate MM subsystem to C++

xtoskrnl/mm/i686/paging.cc

@@ -0,0 +1,54 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            xtoskrnl/mm/i686/paging.cc
+ * DESCRIPTION:     Architecture dependent paging support
+ * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
+ *                  Aiken Harris <harraiken91@gmail.com>
+ */
+
+#include <xtos.hh>
+
+
+/**
+ * Checks if eXtended Physical Addressing (XPA) is enabled.
+ *
+ * @return This routine returns TRUE if PAE is enabled, or FALSE otherwise.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+BOOLEAN
+MM::Paging::GetExtendedPhysicalAddressingStatus(VOID)
+{
+    /* Check if PAE is enabled */
+    return ((AR::CpuFunc::ReadControlRegister(4) & CR4_PAE) != 0) ? TRUE : FALSE;
+}
+
+/**
+ * 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
+MM::Paging::ZeroPages(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");
+}