MdePkg: Clean up source files

[mirror_edk2.git] / MdePkg / Library / BaseLib / X64 / SwitchStack.S

diff --git a/MdePkg/Library/BaseLib/X64/SwitchStack.S b/MdePkg/Library/BaseLib/X64/SwitchStack.S
index 144329083e134a1cff0275fabc4b0ba68798acdc..5ce2612a7b4d98b55cfa90f214c2efeabdc83fd2 100644 (file)
--- a/MdePkg/Library/BaseLib/X64/SwitchStack.S
+++ b/MdePkg/Library/BaseLib/X64/SwitchStack.S
@@ -1,10 +1,10 @@
 #------------------------------------------------------------------------------\r
 #\r
-# Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>\r
+# Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>\r
 # This program and the accompanying materials\r
 # are licensed and made available under the terms and conditions of the BSD License\r
 # which accompanies this distribution.  The full text of the license may be found at\r
-# http://opensource.org/licenses/bsd-license.php\r
+# http://opensource.org/licenses/bsd-license.php.\r
 #\r
 # THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
 # WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
@@ -28,7 +28,7 @@
 #   (rcx) EntryPoint    - Entry point with new stack.\r
 #   (rdx) Context1      - Parameter1 for entry point.\r
 #   (r8)  Context2      - Parameter2 for entry point.\r
-#   (r9)  NewStack      - Pointer to new stack.\r
+#   (r9)  NewStack      - The pointer to new stack.\r
 #\r
 # Returns:\r
 #\r
@@ -37,7 +37,10 @@
 #------------------------------------------------------------------------------\r
 ASM_GLOBAL ASM_PFX(InternalSwitchStack)\r
 ASM_PFX(InternalSwitchStack):\r
-    mov     %rcx, %rax\r
+    pushq   %rbp\r
+    movq    %rsp, %rbp\r
+\r
+    mov     %rcx, %rax  // Shift registers for new call\r
     mov     %rdx, %rcx\r
     mov     %r8, %rdx\r
     #\r
@@ -45,4 +48,5 @@ ASM_PFX(InternalSwitchStack):
     # in case the callee wishes to spill them.\r
     #\r
     lea     -0x20(%r9), %rsp\r
-    call    *%rax\r
+    pushq   $0        // stop gdb stack unwind\r
+    jmp     *%rax     // call EntryPoint ()\r