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UefiCpuPkg: Update BFV searching algorithm in VTF0

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REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3870
The new algorithm searches FFS3 GUID first and then FFS2 GUID at
every 4KB address in the top 16MB just below 4GB.

Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Debkumar De <debkumar.de@intel.com>
Cc: Harry Han <harry.han@intel.com>
Cc: Catharine West <catharine.west@intel.com>
Reviewed-by: Min Xu <min.m.xu@intel.com>
Signed-off-by: Ted Kuo <ted.kuo@intel.com>
This commit is contained in:
Kuo, Ted
2022-03-17 16:38:32 +08:00
committed by mergify[bot]
parent ec30a4a0c3
commit 3ef2071927
10 changed files with 6 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
UefiCpuPkg/ResetVector/Vtf0/Ia32/SearchForBfvBase.asm
View File

@@ -2,7 +2,7 @@
; @file
; Search for the Boot Firmware Volume (BFV) base address
;
; Copyright (c) 2008 - 2009, Intel Corporation. All rights reserved.<BR>
; Copyright (c) 2008 - 2022, Intel Corporation. All rights reserved.<BR>
; SPDX-License-Identifier: BSD-2-Clause-Patent
;
;------------------------------------------------------------------------------
@@ -32,7 +32,6 @@ BITS 32
Flat32SearchForBfvBase:
xor eax, eax
mov ecx, 3 ; 3: FFS3 GUID, 2: FFS2 GUID, 1: Not Found
searchingForBfvHeaderLoop:
;
; We check for a firmware volume at every 4KB address in the top 16MB
@@ -40,21 +39,19 @@ searchingForBfvHeaderLoop:
;
sub eax, 0x1000
cmp eax, 0xff000000
jb searchingForBfvWithOtherFfsGuid
cmp ecx, 3
jne searchingForFfs2Guid
jb searchedForBfvHeaderButNotFound
;
; Check FFS3 GUID
;
cmp dword [eax + 0x10], FFS3_GUID_DWORD0
jne searchingForBfvHeaderLoop
jne searchingForFfs2Guid
cmp dword [eax + 0x14], FFS3_GUID_DWORD1
jne searchingForBfvHeaderLoop
jne searchingForFfs2Guid
cmp dword [eax + 0x18], FFS3_GUID_DWORD2
jne searchingForBfvHeaderLoop
jne searchingForFfs2Guid
cmp dword [eax + 0x1c], FFS3_GUID_DWORD3
jne searchingForBfvHeaderLoop
jne searchingForFfs2Guid
jmp checkingFvLength
searchingForFfs2Guid:
@@ -82,12 +79,6 @@ checkingFvLength:
jmp searchedForBfvHeaderAndItWasFound
searchingForBfvWithOtherFfsGuid:
xor eax, eax
dec ecx
cmp ecx, 1
jne searchingForBfvHeaderLoop
searchedForBfvHeaderButNotFound:
;
; Hang if the SEC entry point was not found