remove unnecessary comments introduced by tools from MdePkg. The regular express...

[mirror_edk2.git] / MdePkg / Library / BaseLib / Ia32 / EnablePaging32.c

diff --git a/MdePkg/Library/BaseLib/Ia32/EnablePaging32.c b/MdePkg/Library/BaseLib/Ia32/EnablePaging32.c
index 146089cab62263fe78f7dd8f66f5229cc2856016..8d963e15d0c32fae26588ff8a5b2e266e6c58df2 100644 (file)
--- a/MdePkg/Library/BaseLib/Ia32/EnablePaging32.c
+++ b/MdePkg/Library/BaseLib/Ia32/EnablePaging32.c
@@ -1,7 +1,7 @@
 /** @file\r
   AsmEnablePaging32 function\r
 \r
-  Copyright (c) 2006, Intel Corporation<BR>\r
+  Copyright (c) 2006 - 2007, Intel Corporation<BR>\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
@@ -12,8 +12,44 @@
 \r
 **/\r
 \r
+\r
+#include <BaseLibInternals.h>\r
+\r
 #if _MSC_EXTENSIONS\r
 \r
+/**\r
+  Enables the 32-bit paging mode on the CPU.\r
+\r
+  Enables the 32-bit paging mode on the CPU. CR0, CR3, CR4, and the page tables\r
+  must be properly initialized prior to calling this service. This function\r
+  assumes the current execution mode is 32-bit protected mode. This function is\r
+  only available on IA-32. After the 32-bit paging mode is enabled, control is\r
+  transferred to the function specified by EntryPoint using the new stack\r
+  specified by NewStack and passing in the parameters specified by Context1 and\r
+  Context2. Context1 and Context2 are optional and may be NULL. The function\r
+  EntryPoint must never return.\r
+\r
+  There are a number of constraints that must be followed before calling this\r
+  function:\r
+  1)  Interrupts must be disabled.\r
+  2)  The caller must be in 32-bit protected mode with flat descriptors. This\r
+      means all descriptors must have a base of 0 and a limit of 4GB.\r
+  3)  CR0 and CR4 must be compatible with 32-bit protected mode with flat\r
+      descriptors.\r
+  4)  CR3 must point to valid page tables that will be used once the transition\r
+      is complete, and those page tables must guarantee that the pages for this\r
+      function and the stack are identity mapped.\r
+\r
+  @param  EntryPoint  A pointer to function to call with the new stack after\r
+                      paging is enabled.\r
+  @param  Context1    A pointer to the context to pass into the EntryPoint\r
+                      function as the first parameter after paging is enabled.\r
+  @param  Context2    A pointer to the context to pass into the EntryPoint\r
+                      function as the second parameter after paging is enabled.\r
+  @param  NewStack    A pointer to the new stack to use for the EntryPoint\r
+                      function after paging is enabled.\r
+\r
+**/\r
 __declspec (naked)\r
 VOID\r
 EFIAPI\r