diff options
Diffstat (limited to 'OvmfPkg/Sec/Ia32/SwitchStack.c')
| -rw-r--r-- | OvmfPkg/Sec/Ia32/SwitchStack.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/OvmfPkg/Sec/Ia32/SwitchStack.c b/OvmfPkg/Sec/Ia32/SwitchStack.c new file mode 100644 index 0000000000..54fde9494a --- /dev/null +++ b/OvmfPkg/Sec/Ia32/SwitchStack.c @@ -0,0 +1,136 @@ +/** @file
+ Switch Stack functions.
+
+ Copyright (c) 2006 - 2007, Intel Corporation<BR>
+ All rights reserved. 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 common header file for this module.
+//
+
+
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/PeiServicesLib.h>
+
+/**
+ Transfers control to a function starting with a new stack.
+
+ Transfers control 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 NULL. The function
+ EntryPoint must never return.
+
+ If EntryPoint is NULL, then ASSERT().
+ If NewStack is NULL, then ASSERT().
+
+ @param EntryPoint A pointer to function to call with the new stack.
+ @param Context1 A pointer to the context to pass into the EntryPoint
+ function.
+ @param Context2 A pointer to the context to pass into the EntryPoint
+ function.
+ @param NewStack A pointer to the new stack to use for the EntryPoint
+ function.
+ @param NewBsp A pointer to the new BSP for the EntryPoint on IPF. It's
+ Reserved on other architectures.
+
+**/
+VOID
+EFIAPI
+PeiSwitchStacks (
+ IN SWITCH_STACK_ENTRY_POINT EntryPoint,
+ IN VOID *Context1, OPTIONAL
+ IN VOID *Context2, OPTIONAL
+ IN VOID *Context3, OPTIONAL
+ IN VOID *OldTopOfStack,
+ IN VOID *NewStack
+ )
+{
+ BASE_LIBRARY_JUMP_BUFFER JumpBuffer;
+
+ ASSERT (EntryPoint != NULL);
+ ASSERT (NewStack != NULL);
+
+ //
+ // Stack should be aligned with CPU_STACK_ALIGNMENT
+ //
+ ASSERT (((UINTN)NewStack & (CPU_STACK_ALIGNMENT - 1)) == 0);
+
+ JumpBuffer.Eip = (UINTN)EntryPoint;
+ JumpBuffer.Esp = (UINTN)NewStack - sizeof (VOID*);
+ JumpBuffer.Esp -= sizeof (Context1) + sizeof (Context2) + sizeof(Context3);
+ ((VOID**)JumpBuffer.Esp)[1] = Context1;
+ ((VOID**)JumpBuffer.Esp)[2] = Context2;
+ ((VOID**)JumpBuffer.Esp)[3] = Context3;
+
+ LongJump (&JumpBuffer, (UINTN)-1);
+
+ //
+ // InternalSwitchStack () will never return
+ //
+ ASSERT (FALSE);
+}
+
+/**
+ Transfers control to a function starting with a new stack.
+
+ Transfers control 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 NULL. The function
+ EntryPoint must never return.
+
+ If EntryPoint is NULL, then ASSERT().
+ If NewStack is NULL, then ASSERT().
+
+ @param EntryPoint A pointer to function to call with the new stack.
+ @param Context1 A pointer to the context to pass into the EntryPoint
+ function.
+ @param Context2 A pointer to the context to pass into the EntryPoint
+ function.
+ @param NewStack A pointer to the new stack to use for the EntryPoint
+ function.
+ @param NewBsp A pointer to the new BSP for the EntryPoint on IPF. It's
+ Reserved on other architectures.
+
+**/
+VOID
+EFIAPI
+SecSwitchStack (
+ IN UINTN TemporaryMemoryBase,
+ IN UINTN PermanentMemoryBase,
+ IN UINTN CopySize
+ )
+{
+ BASE_LIBRARY_JUMP_BUFFER JumpBuffer;
+ UINTN SetJumpFlag;
+
+ ASSERT ((VOID*)TemporaryMemoryBase != NULL);
+ ASSERT ((VOID*)PermanentMemoryBase != NULL);
+
+ SetJumpFlag = SetJump (&JumpBuffer);
+ //
+ // The initial call to SetJump() must always return 0.
+ // Subsequent calls to LongJump() may cause a non-zero value to be returned by SetJump().
+ //
+ if (SetJumpFlag == 0) {
+ DEBUG ((EFI_D_ERROR, "SecSwitchStack+%d: Esp: 0x%xL\n", __LINE__, JumpBuffer.Esp));
+ JumpBuffer.Esp =
+ (INTN)JumpBuffer.Esp -
+ (INTN)TemporaryMemoryBase +
+ (INTN)PermanentMemoryBase;
+ MemoryFence ();
+ CopyMem((VOID*)PermanentMemoryBase, (VOID*)TemporaryMemoryBase, CopySize);
+ LongJump (&JumpBuffer, (UINTN)-1);
+ }
+
+}
+
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