1. Remove .extern from GCC assembly.

[mirror_edk2.git] / MdePkg / Library / BaseLib / X64 / DisablePaging64.S

diff --git a/MdePkg/Library/BaseLib/X64/DisablePaging64.S b/MdePkg/Library/BaseLib/X64/DisablePaging64.S
index 7a543febabc3e2a1656213fd9a77254e2d855e09..f3ed29ed402d3bc5cb37f37572af6948d4e08f3d 100644 (file)
--- a/MdePkg/Library/BaseLib/X64/DisablePaging64.S
+++ b/MdePkg/Library/BaseLib/X64/DisablePaging64.S
@@ -1,65 +1,67 @@
-#------------------------------------------------------------------------------
-#
-# Copyright (c) 2006 - 2008, Intel Corporation
-# 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.
-#
-# Module Name:
-#
-#   DisablePaging64.S
-#
-# Abstract:
-#
-#   AsmDisablePaging64 function
-#
-# Notes:
-#
-#------------------------------------------------------------------------------
-
-    
-
-#------------------------------------------------------------------------------
-# VOID
-# EFIAPI
-# InternalX86DisablePaging64 (
-#   IN      UINT16                    Cs,                      %rdi
-#   IN      UINT64                    EntryPoint,              %rsi
-#   IN      UINT64                    Context1,  OPTIONAL      %rdx
-#   IN      UINT32                    Context2,  OPTIONAL      %rcx
-#   IN      UINT64                    NewStack                 %r8
-#   );
-#------------------------------------------------------------------------------
-
-.global ASM_PFX(InternalX86DisablePaging64)
-ASM_PFX(InternalX86DisablePaging64):
-    cli    
-    shl    $0x20,%rcx
-    lea    L1, %eax
+#------------------------------------------------------------------------------\r
+#\r
+# Copyright (c) 2006 - 2008, Intel Corporation\r
+# All rights reserved. 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
+#\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
+#\r
+# Module Name:\r
+#\r
+#   DisablePaging64.S\r
+#\r
+# Abstract:\r
+#\r
+#   AsmDisablePaging64 function\r
+#\r
+# Notes:\r
+#\r
+#------------------------------------------------------------------------------\r
+\r
+    \r
+\r
+#------------------------------------------------------------------------------\r
+# VOID\r
+# EFIAPI\r
+# InternalX86DisablePaging64 (\r
+#   IN      UINT16                    Cs,\r
+#   IN      UINT64                    EntryPoint,\r
+#   IN      UINT64                    Context1,  OPTIONAL\r
+#   IN      UINT32                    Context2,  OPTIONAL\r
+#   IN      UINT64                    NewStack\r
+#   );\r
+#------------------------------------------------------------------------------\r
+\r
+ASM_GLOBAL ASM_PFX(InternalX86DisablePaging64)\r
+ASM_PFX(InternalX86DisablePaging64):\r
+    cli    \r
+    shl    $0x20,%rcx                     # rcx[32..47] <- Cs\r
+    lea    L1, %eax\r
     mov    %r8d, %esi \r
-    or     %rax, %rcx\r
+    or     %rax, %rcx                     # rcx[0..47] <- Cs:@F\r
     mov    %r9d, %edi \r
-    mov    0x28(%rsp), %eax\r
+    mov    0x28(%rsp), %eax               # eax <- New Stack\r
     push   %rcx\r
-    ret\r
-L1:
-    mov    %eax,%esp
-    mov    %cr0,%rax
-    btr    $0x1f,%eax
-    mov    %rax,%cr0
-    mov    $0xc0000080,%ecx
-    rdmsr  
-    and    $0xfe,%ah
-    wrmsr  
-    mov    %cr4,%rax
-    and    $0xdf,%al
-    mov    %rax,%cr4
-    push   %rdi
-    push   %rsi
-    callq  *%rdx
-    jmp    .
-
+    ret                                   # switch to compatibility mode\r
+L1:\r
+    mov    %eax,%esp                      # set up new stack\r
+    mov    %cr0,%rax\r
+    btr    $0x1f,%eax\r
+    mov    %rax,%cr0                      # disable paging\r
+\r
+    mov    %rdx,%rbx                      # save EntryPoint to rbx, for rdmsr will overwrite rdx\r
+    mov    $0xc0000080,%ecx\r
+    rdmsr  \r
+    and    $0xfe,%ah                      # clear LME\r
+    wrmsr  \r
+    mov    %cr4,%rax\r
+    and    $0xdf,%al                      # clear PAE\r
+    mov    %rax,%cr4\r
+    push   %rdi                           # push Context2\r
+    push   %rsi                           # push Context1\r
+    callq  *%rbx                          # transfer control to EntryPoint\r
+    jmp    .                              # no one should get here\r
+\r