From ef89b11ce6f93c96fbd1753a8006dd9c3da212e0 Mon Sep 17 00:00:00 2001
From: ReddestDream <reddestdream@gmail.com>
Date: Wed, 3 May 2017 00:13:28 -0400
Subject: [PATCH] CbSupportPei: prevent lower coreboot table from being
 overwritten

Exclude the bottom 4kb from being included in System Memory HoB

diff --git a/CorebootModulePkg/CbSupportPei/CbSupportPei.c b/CorebootModulePkg/CbSupportPei/CbSupportPei.c
index 262e6b9..d3c5723 100755
--- a/CorebootModulePkg/CbSupportPei/CbSupportPei.c
+++ b/CorebootModulePkg/CbSupportPei/CbSupportPei.c
@@ -261,8 +261,9 @@ CbPeiEntryPoint (
     EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
     EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE
     ),
-    (EFI_PHYSICAL_ADDRESS)(0),
-    (UINT64)(0xA0000)
+    // Lower 640KB, except for first 4KB where the lower coreboot pointer ("LBIO") resides
+    (EFI_PHYSICAL_ADDRESS)(0 + 0x1000),
+    (UINT64)(0xA0000 - 0x1000)
     );


--
2.14.0