1 files changed, 63 insertions, 0 deletions
diff --git a/UnixPkg/Library/UnixBaseLib/X86DisablePaging64.c b/UnixPkg/Library/UnixBaseLib/X86DisablePaging64.c
new file mode 100644
index 0000000000..add86cc6eb
--- /dev/null
+++ b/UnixPkg/Library/UnixBaseLib/X86DisablePaging64.c
@@ -0,0 +1,63 @@
+/** @file
+  IA-32/x64 AsmDisablePaging64()
+
+  Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
+  This program and the accompanying materials
+  are licensed and made available under the terms and conditions of the BSD License
+  which accompanies this distribution.  The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php.
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+
+
+
+#include "BaseLibInternals.h"
+
+/**
+  Disables the 64-bit paging mode on the CPU.
+
+  Disables the 64-bit paging mode on the CPU and returns to 32-bit protected
+  mode. This function assumes the current execution mode is 64-paging mode.
+  This function is only available on x64. After the 64-bit paging mode is
+  disabled, control is transferred to the function specified by EntryPoint
+  using the new stack specified by NewStack and passing in the parameters
+  specified by Context1 and Context2. Context1 and Context2 are optional and
+  may be 0. The function EntryPoint must never return.
+
+  If the current execution mode is not 64-bit paged mode, then ASSERT().
+  If EntryPoint is 0, then ASSERT().
+  If NewStack is 0, then ASSERT().
+
+  @param  Cs          The 16-bit selector to load in the CS before EntryPoint
+                      is called. The descriptor in the GDT that this selector
+                      references must be setup for 32-bit protected mode.
+  @param  EntryPoint  The 64-bit virtual address of the function to call with
+                      the new stack after paging is disabled.
+  @param  Context1    The 64-bit virtual address of the context to pass into
+                      the EntryPoint function as the first parameter after
+                      paging is disabled.
+  @param  Context2    The 64-bit virtual address of the context to pass into
+                      the EntryPoint function as the second parameter after
+                      paging is disabled.
+  @param  NewStack    The 64-bit virtual address of the new stack to use for
+                      the EntryPoint function after paging is disabled.
+
+**/
+VOID
+EFIAPI
+AsmDisablePaging64 (
+  IN      UINT16                    Cs,
+  IN      UINT32                    EntryPoint,
+  IN      UINT32                    Context1,  OPTIONAL
+  IN      UINT32                    Context2,  OPTIONAL
+  IN      UINT32                    NewStack
+  )
+{
+  ASSERT (EntryPoint != 0);
+  ASSERT (NewStack != 0);
+  InternalX86DisablePaging64 (Cs, EntryPoint, Context1, Context2, NewStack);
+}