1 files changed, 33 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseLib/Ia32/EnablePaging32.c b/MdePkg/Library/BaseLib/Ia32/EnablePaging32.c
index 3cb290c..87e31ca 100644
--- a/MdePkg/Library/BaseLib/Ia32/EnablePaging32.c
+++ b/MdePkg/Library/BaseLib/Ia32/EnablePaging32.c
@@ -19,6 +19,39 @@
 
 #if _MSC_EXTENSIONS
 
+/**
+  Enables the 32-bit paging mode on the CPU.
+
+  Enables the 32-bit paging mode on the CPU. CR0, CR3, CR4, and the page tables
+  must be properly initialized prior to calling this service. This function
+  assumes the current execution mode is 32-bit protected mode. This function is
+  only available on IA-32. After the 32-bit paging mode is enabled, control is
+  transferred to the function specified by EntryPoint using the new stack
+  specified by NewStack and passing in the parameters specified by Context1 and
+  Context2. Context1 and Context2 are optional and may be NULL. The function
+  EntryPoint must never return.
+
+  There are a number of constraints that must be followed before calling this
+  function:
+  1)  Interrupts must be disabled.
+  2)  The caller must be in 32-bit protected mode with flat descriptors. This
+      means all descriptors must have a base of 0 and a limit of 4GB.
+  3)  CR0 and CR4 must be compatible with 32-bit protected mode with flat
+      descriptors.
+  4)  CR3 must point to valid page tables that will be used once the transition
+      is complete, and those page tables must guarantee that the pages for this
+      function and the stack are identity mapped.
+
+  @param  EntryPoint  A pointer to function to call with the new stack after
+                      paging is enabled.
+  @param  Context1    A pointer to the context to pass into the EntryPoint
+                      function as the first parameter after paging is enabled.
+  @param  Context2    A pointer to the context to pass into the EntryPoint
+                      function as the second parameter after paging is enabled.
+  @param  NewStack    A pointer to the new stack to use for the EntryPoint
+                      function after paging is enabled.
+
+**/
 __declspec (naked)
 VOID
 EFIAPI