UefiCpuPkg/MpInitLib: split wake up buffer into two parts

[mirror_edk2.git] / UefiCpuPkg / Library / MpInitLib / PeiMpLib.c

diff --git a/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c b/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c
index 70c2bc7323f6d05d418a8b823cab21f1c3e49de5..ad43bd33f5f820c0c00192c33b22966ce678f5d7 100644 (file)
--- a/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/PeiMpLib.c
@@ -187,6 +187,29 @@ GetWakeupBuffer (
   return (UINTN) -1;\r
 }\r
 \r
+/**\r
+  Get available EfiBootServicesCode memory below 4GB by specified size.\r
+\r
+  This buffer is required to safely transfer AP from real address mode to\r
+  protected mode or long mode, due to the fact that the buffer returned by\r
+  GetWakeupBuffer() may be marked as non-executable.\r
+\r
+  @param[in] BufferSize   Wakeup transition buffer size.\r
+\r
+  @retval other   Return wakeup transition buffer address below 4GB.\r
+  @retval 0       Cannot find free memory below 4GB.\r
+**/\r
+UINTN\r
+GetModeTransitionBuffer (\r
+  IN UINTN                BufferSize\r
+  )\r
+{\r
+  //\r
+  // PEI phase doesn't need to do such transition. So simply return 0.\r
+  //\r
+  return 0;\r
+}\r
+\r
 /**\r
   Checks APs status and updates APs status if needed.\r
 \r