Code Scrub for MdePkg.

[mirror_edk2.git] / MdePkg / Library / BaseLib / Ia32 / DisablePaging32.c

diff --git a/MdePkg/Library/BaseLib/Ia32/DisablePaging32.c b/MdePkg/Library/BaseLib/Ia32/DisablePaging32.c
index d462c01ff398ab8268bd6840a523c997c5e4b643..1ab21224ca67d0db481b19dbe287e914a5c79dde 100644 (file)
--- a/MdePkg/Library/BaseLib/Ia32/DisablePaging32.c
+++ b/MdePkg/Library/BaseLib/Ia32/DisablePaging32.c
@@ -19,6 +19,36 @@
 \r
 #if _MSC_EXTENSIONS\r
 \r
+/**\r
+  Disables the 32-bit paging mode on the CPU.\r
+\r
+  Disables the 32-bit paging mode on the CPU and returns to 32-bit protected\r
+  mode. This function assumes the current execution mode is 32-paged protected\r
+  mode. This function is only available on IA-32. After the 32-bit paging mode\r
+  is disabled, control is transferred to the function specified by EntryPoint\r
+  using the new stack specified by NewStack and passing in the parameters\r
+  specified by Context1 and Context2. Context1 and Context2 are optional and\r
+  may be NULL. The function 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 paged mode.\r
+  3)  CR0, CR3, and CR4 must be compatible with 32-bit paged mode.\r
+  4)  CR3 must point to valid page tables that guarantee that the pages for\r
+      this 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 disabled.\r
+  @param  Context1    A pointer to the context to pass into the EntryPoint\r
+                      function as the first parameter after paging is disabled.\r
+  @param  Context2    A pointer to the context to pass into the EntryPoint\r
+                      function as the second parameter after paging is\r
+                      disabled.\r
+  @param  NewStack    A pointer to the new stack to use for the EntryPoint\r
+                      function after paging is disabled.\r
+\r
+**/\r
 __declspec (naked)\r
 VOID\r
 EFIAPI\r