diff --git a/reactos/ntoskrnl/ex/i386/ioport.S b/reactos/ntoskrnl/ex/i386/ioport.S
new file mode 100644
index 00000000000..285e866d130
--- /dev/null
+++ b/reactos/ntoskrnl/ex/i386/ioport.S
@@ -0,0 +1,220 @@
+/*
+ * COPYRIGHT:       See COPYING in the top level directory
+ * PROJECT:         ReactOS kernel
+ * FILE:            ntoskrnl/ex/i386/ioport.S
+ * PURPOSE:         FASTCALL Interlocked Functions
+ * PROGRAMMERS:     Alex Ionescu (alex@relsoft.net)
+ */
+
+/* INCLUDES ******************************************************************/
+
+#include <ndk/asm.h>
+.intel_syntax noprefix
+
+/* GLOBALS *******************************************************************/
+
+.globl _READ_REGISTER_UCHAR@4
+.globl _READ_REGISTER_USHORT@4
+.globl _READ_REGISTER_ULONG@4
+.globl _READ_REGISTER_BUFFER_UCHAR@12
+.globl _READ_REGISTER_BUFFER_USHORT@12
+.globl _READ_REGISTER_BUFFER_ULONG@12
+.globl _WRITE_REGISTER_UCHAR@8
+.globl _WRITE_REGISTER_USHORT@8
+.globl _WRITE_REGISTER_ULONG@8
+.globl _WRITE_REGISTER_BUFFER_UCHAR@12
+.globl _WRITE_REGISTER_BUFFER_USHORT@12
+.globl _WRITE_REGISTER_BUFFER_ULONG@12
+
+/* FUNCTIONS *****************************************************************/
+
+.func READ_REGISTER_UCHAR@4
+_READ_REGISTER_UCHAR@4:
+
+    /* Return the requested memory location */
+    mov edx, [esp+4]
+    mov al, [edx]
+    ret 4
+.endfunc
+
+.func READ_REGISTER_USHORT@4
+_READ_REGISTER_USHORT@4:
+
+    /* Return the requested memory location */
+    mov edx, [esp+4]
+    mov ax, [edx]
+    ret 4
+.endfunc
+
+.func READ_REGISTER_ULONG@4
+_READ_REGISTER_ULONG@4:
+
+    /* Return the requested memory location */
+    mov edx, [esp+4]
+    mov eax, [edx]
+    ret 4
+.endfunc
+
+.func READ_REGISTER_BUFFER_UCHAR@12
+_READ_REGISTER_BUFFER_UCHAR@12:
+
+    /* Save volatiles */
+    mov eax, esi
+    mov edx, edi
+
+    /* Do the transfer */
+    mov ecx, [esp+12]
+    mov esi, [esp+4]
+    mov edi, [esp+8]
+    rep movsb
+
+    /* Restore volatiles and return */
+    mov edi, edx
+    mov esi, eax
+    ret 12
+.endfunc
+
+.func READ_REGISTER_BUFFER_USHORT@12
+_READ_REGISTER_BUFFER_USHORT@12:
+
+    /* Save volatiles */
+    mov eax, esi
+    mov edx, edi
+
+    /* Do the transfer */
+    mov ecx, [esp+12]
+    mov esi, [esp+4]
+    mov edi, [esp+8]
+    rep movsw
+
+    /* Restore volatiles and return */
+    mov edi, edx
+    mov esi, eax
+    ret 12
+.endfunc
+
+.func READ_REGISTER_BUFFER_ULONG@12
+_READ_REGISTER_BUFFER_ULONG@12:
+
+    /* Save volatiles */
+    mov eax, esi
+    mov edx, edi
+
+    /* Do the transfer */
+    mov ecx, [esp+12]
+    mov esi, [esp+4]
+    mov edi, [esp+8]
+    rep movsd
+
+    /* Restore volatiles and return */
+    mov edi, edx
+    mov esi, eax
+    ret 12
+.endfunc
+
+.func WRITE_REGISTER_UCHAR@8
+_WRITE_REGISTER_UCHAR@8:
+
+    /* Write to memory */
+    mov edx, [esp+4]
+    mov al, [esp+8]
+    mov [edx], al
+
+    /* Flush posted write buffers and return */
+    lock or [esp+4], edx
+    ret 8
+.endfunc
+
+.func WRITE_REGISTER_USHORT@8
+_WRITE_REGISTER_USHORT@8:
+
+    /* Write to memory */
+    mov edx, [esp+4]
+    mov eax, [esp+8]
+    mov [edx], ax
+
+    /* Flush posted write buffers and return */
+    lock or [esp+4], edx
+    ret 8
+.endfunc
+
+.func WRITE_REGISTER_ULONG@8
+_WRITE_REGISTER_ULONG@8:
+
+    /* Write to memory */
+    mov edx, [esp+4]
+    mov eax, [esp+8]
+    mov [edx], eax
+
+    /* Flush posted write buffers and return */
+    lock or [esp+4], edx
+    ret 8
+.endfunc
+
+.func WRITE_REGISTER_BUFFER_UCHAR@12
+_WRITE_REGISTER_BUFFER_UCHAR@12:
+
+    /* Save volatiles */
+    mov eax, esi
+    mov edx, edi
+
+    /* Do the transfer */
+    mov ecx, [esp+12]
+    mov esi, [esp+8]
+    mov edi, [esp+4]
+    rep movsb
+
+    /* Flush posted write buffers */
+    lock or [esp+4], ecx
+
+    /* Restole volatiles and return */
+    mov edi, edx
+    mov esi, eax
+    ret 12
+.endfunc
+
+.func WRITE_REGISTER_BUFFER_USHORT@12
+_WRITE_REGISTER_BUFFER_USHORT@12:
+
+    /* Save volatiles */
+    mov eax, esi
+    mov edx, edi
+
+    /* Do the transfer */
+    mov ecx, [esp+12]
+    mov esi, [esp+8]
+    mov edi, [esp+4]
+    rep movsw
+
+    /* Flush posted write buffers */
+    lock or [esp+4], ecx
+
+    /* Restole volatiles and return */
+    mov edi, edx
+    mov esi, eax
+    ret 12
+.endfunc
+
+.func WRITE_REGISTER_BUFFER_ULONG@12
+_WRITE_REGISTER_BUFFER_ULONG@12:
+
+    /* Save volatiles */
+    mov eax, esi
+    mov edx, edi
+
+    /* Do the transfer */
+    mov ecx, [esp+12]
+    mov esi, [esp+8]
+    mov edi, [esp+4]
+    rep movsd
+
+    /* Flush posted write buffers */
+    lock or [esp+4], ecx
+
+    /* Restole volatiles and return */
+    mov edi, edx
+    mov esi, eax
+    ret 12
+.endfunc
+
+/* EOF */
diff --git a/reactos/ntoskrnl/ntoskrnl.rbuild b/reactos/ntoskrnl/ntoskrnl.rbuild
index 86f55d7f1da..3a7c86ef22d 100644
--- a/reactos/ntoskrnl/ntoskrnl.rbuild
+++ b/reactos/ntoskrnl/ntoskrnl.rbuild
@@ -125,6 +125,7 @@
             <directory name="i386">
                 <file>interlck_asm.S</file>
                 <file>fastinterlck_asm.S</file>
+                <file>ioport.S</file>
             </directory>
         </if>
             <file>atom.c</file>
@@ -333,7 +334,6 @@
         </if>
             <file>libsupp.c</file>
             <file>misc.c</file>
-            <file>regio.c</file>
             <file>strtok.c</file>
     </directory>
     <directory name="se">
diff --git a/reactos/ntoskrnl/rtl/regio.c b/reactos/ntoskrnl/rtl/regio.c
deleted file mode 100644
index 1f6162da4c1..00000000000
--- a/reactos/ntoskrnl/rtl/regio.c
+++ /dev/null
@@ -1,190 +0,0 @@
-/* $Id$
- *
- * COPYRIGHT:       See COPYING in the top level directory
- * PROJECT:         ReactOS kernel
- * FILE:            ntoskrnl/rtl/regio.c
- * PURPOSE:         Register io functions
- *
- * PROGRAMMERS:     Eric Kohl (ekohl@abo.rhein-zeitung.de)
- */
-
-#include <ntoskrnl.h>
-
-
-/* FUNCTIONS ***************************************************************/
-
-UCHAR
-STDCALL
-READ_REGISTER_UCHAR (
-	PUCHAR	Register
-	)
-{
-	return *Register;
-}
-
-/*
- * @implemented
- */
-USHORT
-STDCALL
-READ_REGISTER_USHORT (
-	PUSHORT	Register
-	)
-{
-	return *Register;
-}
-
-/*
- * @implemented
- */
-ULONG
-STDCALL
-READ_REGISTER_ULONG (
-	PULONG	Register
-	)
-{
-	return *Register;
-}
-
-/*
- * @implemented
- */
-VOID
-STDCALL
-READ_REGISTER_BUFFER_UCHAR (
-	PUCHAR	Register,
-	PUCHAR	Buffer,
-	ULONG	Count
-	)
-{
-	while (Count--)
-	{
-		*Buffer++  = *Register++;
-	}
-}
-
-/*
- * @implemented
- */
-VOID
-STDCALL
-READ_REGISTER_BUFFER_USHORT (
-	PUSHORT	Register,
-	PUSHORT	Buffer,
-	ULONG	Count
-	)
-{
-	while (Count--)
-	{
-		*Buffer++  = *Register++;
-	}
-}
-
-/*
- * @implemented
- */
-VOID
-STDCALL
-READ_REGISTER_BUFFER_ULONG (
-	PULONG	Register,
-	PULONG	Buffer,
-	ULONG	Count
-	)
-{
-	while (Count--)
-	{
-		*Buffer++  = *Register++;
-	}
-}
-
-/*
- * @implemented
- */
-VOID
-STDCALL
-WRITE_REGISTER_UCHAR (
-	PUCHAR	Register,
-	UCHAR	Value
-	)
-{
-	*Register = Value;
-}
-
-/*
- * @implemented
- */
-VOID
-STDCALL
-WRITE_REGISTER_USHORT (
-	PUSHORT	Register,
-	USHORT	Value
-	)
-{
-	*Register = Value;
-}
-
-/*
- * @implemented
- */
-VOID
-STDCALL
-WRITE_REGISTER_ULONG (
-	PULONG	Register,
-	ULONG	Value
-	)
-{
-	*Register = Value;
-}
-
-/*
- * @implemented
- */
-VOID
-STDCALL
-WRITE_REGISTER_BUFFER_UCHAR (
-	PUCHAR	Register,
-	PUCHAR	Buffer,
-	ULONG	Count
-	)
-{
-	while (Count--)
-	{
-		*Register++  = *Buffer++;
-	}
-}
-
-/*
- * @implemented
- */
-VOID
-STDCALL
-WRITE_REGISTER_BUFFER_USHORT (
-	PUSHORT	Register,
-	PUSHORT	Buffer,
-	ULONG	Count
-	)
-{
-	while (Count--)
-	{
-		*Register++  = *Buffer++;
-	}
-}
-
-/*
- * @implemented
- */
-VOID
-STDCALL
-WRITE_REGISTER_BUFFER_ULONG (
-	PULONG	Register,
-	PULONG	Buffer,
-	ULONG	Count
-)
-{
-	while (Count--)
-	{
-		*Register++  = *Buffer++;
-	}
-}
-
-/* EOF */