1 files changed, 111 insertions, 0 deletions
diff --git a/UnixPkg/Sec/X64/SwitchStack.S b/UnixPkg/Sec/X64/SwitchStack.S
new file mode 100644
index 000000000..acc3df232
--- /dev/null
+++ b/UnixPkg/Sec/X64/SwitchStack.S
@@ -0,0 +1,111 @@
+#------------------------------------------------------------------------------
+#
+# 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.
+#
+# Module Name:
+#
+#   SwitchStack.S
+#
+# Abstract:
+#
+#------------------------------------------------------------------------------
+
+
+#------------------------------------------------------------------------------
+# Routine Description:
+#
+#   Routine for switching stacks with 3 parameters EFI ABI
+#
+# Arguments:
+#
+#   (rcx) EntryPoint    - Entry point with new stack.
+#   (rdx) Context1      - Parameter1 for entry point.
+#   (r8)  Context2      - Parameter2 for entry point.
+#   (r9)  Context3      - Parameter3 for entry point.
+#   (rsp)0x20  NewStack - The pointer to new stack.
+#
+# Returns:
+#
+#   None
+#
+#------------------------------------------------------------------------------
+ASM_GLOBAL ASM_PFX(MsftPeiSwitchStacks)
+ASM_PFX(MsftPeiSwitchStacks):
+    mov     %rcx, %rax
+    mov     %rdx, %rcx
+    mov     %r8, %rdx
+    mov     %r9, %r8
+    
+    # get new stack from the stack
+    mov     0x20(%rsp), %rsp  # is this off by 8?
+    
+    #
+    # Reserve space for register parameters (rcx, rdx, r8 & r9) on the stack,
+    # in case the callee wishes to spill them.
+    #
+    lea     -0x20(%rsp), %rsp
+    call    *%rax
+
+
+#------------------------------------------------------------------------------
+# Routine Description:
+#
+#   Routine for switching stacks with 3 parameters UNIX ABI
+#
+# Arguments:
+#
+#   (rdi) EntryPoint    - Entry point with new stack.
+#   (rsi) Context1      - Parameter1 for entry point.
+#   (rdx) Context2      - Parameter2 for entry point.
+#   (rcx) Context3      - Parameter3 for entry point.
+#   (r8)  NewStack      - The pointer to new stack.
+#
+# Returns:
+#
+#   None
+#
+#------------------------------------------------------------------------------
+ASM_GLOBAL ASM_PFX(PeiSwitchStacks)
+ASM_PFX(PeiSwitchStacks):
+    mov     %rdi, %rax
+    mov     %rsi, %rdi
+    mov     %rdx, %rsi
+    mov     %rcx, %rdx
+    mov     %r8,  %rsp
+    
+    
+    #
+    # Reserve space for redzone on the stack,
+    # in case the callee wishes to spill them.
+    #
+    lea     -0x80(%rsp), %rsp
+    call    *%rax
+
+
+
+#------------------------------------------------------------------------------
+# VOID
+# EFIAPI
+# SecSwitchStack (
+#   UINT32   TemporaryMemoryBase, // Rcx, Rdi
+#   UINT32   PermenentMemoryBase  // Rdx, Rsi
+#   );
+#------------------------------------------------------------------------------    
+ASM_GLOBAL ASM_PFX(SecSwitchStack)
+ASM_PFX(SecSwitchStack):
+
+  mov     %rsp, %rax
+  sub     %rdi, %rax
+  add     %rsi, %rax
+  mov    (%rip), %r10
+  mov    %r10, (%rax) 
+  ret
+  
+  
+\ No newline at end of file