Re: [edk2-devel] [PATCH] UefiCpuPkg/CpuDxe: Fix boot error

["Dong, Eric" <eric.dong@intel.com>]

Reviewed-by: Eric Dong <eric.dong@intel.com>

-----Original Message-----
From: Guo Dong <guo.dong@intel.com> 
Sent: Thursday, December 3, 2020 5:39 AM
To: devel@edk2.groups.io
Cc: Dong, Eric <eric.dong@intel.com>; Ni, Ray <ray.ni@intel.com>; lersek@redhat.com; Kumar, Rahul1 <rahul1.kumar@intel.com>
Subject: [edk2-devel] [PATCH] UefiCpuPkg/CpuDxe: Fix boot error

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3084

When DXE drivers are dispatched above 4GB memory and the system is already in 64bit mode, the address setCodeSelectorLongJump in stack will be override by parameter. so change to use 64bit address and jump to qword address.

Signed-off-by: Guo Dong <guo.dong@intel.com>
---
 UefiCpuPkg/CpuDxe/X64/CpuAsm.nasm | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/UefiCpuPkg/CpuDxe/X64/CpuAsm.nasm b/UefiCpuPkg/CpuDxe/X64/CpuAsm.nasm
index c3489bcc3e..6ad32b49f4 100644
--- a/UefiCpuPkg/CpuDxe/X64/CpuAsm.nasm
+++ b/UefiCpuPkg/CpuDxe/X64/CpuAsm.nasm
@@ -23,8 +23,8 @@ ASM_PFX(SetCodeSelector):
     sub     rsp, 0x10
     lea     rax, [setCodeSelectorLongJump]
     mov     [rsp], rax
-    mov     [rsp+4], cx
-    jmp     dword far [rsp]
+    mov     [rsp+8], cx
+    jmp     qword far [rsp]
 setCodeSelectorLongJump:
     add     rsp, 0x10
     ret
--
2.16.2.windows.1