3 comments starting with "[Ray]".
;#define EFI_FIRMWARE_FILE_SYSTEM2_GUID \
; { 0x8c8ce578, 0x8a3d, 0x4f1c, { 0x99, 0x35, 0x89, 0x61, 0x85, 0xc3, 0x2d,
0xd3 } }
-%define FFS_GUID_DWORD0 0x8c8ce578
-%define FFS_GUID_DWORD1 0x4f1c8a3d
-%define FFS_GUID_DWORD2 0x61893599
-%define FFS_GUID_DWORD3 0xd32dc385
+%define FFS2_GUID_DWORD0 0x8c8ce578
+%define FFS2_GUID_DWORD1 0x4f1c8a3d
+%define FFS2_GUID_DWORD2 0x61893599
+%define FFS2_GUID_DWORD3 0xd32dc385
+
+;#define EFI_FIRMWARE_FILE_SYSTEM3_GUID \
+; { 0x8c8ce578, 0x3dcb, 0x4dca, { 0xbd, 0x6f, 0x1e, 0x96, 0x89, 0xe7, 0x34,
0x9a } }
+%define FFS3_GUID_DWORD0 0x5473c07a
+%define FFS3_GUID_DWORD1 0x4dca3dcb
+%define FFS3_GUID_DWORD2 0x961e6fbd
+%define FFS3_GUID_DWORD3 0x9a34e789
[Ray] 1. I am not sure if it's the best representation of GUID in NASM? I am
not the NASM expert. If there is no recommendation, I am ok with this.
BITS 32
@@ -25,6 +32,7 @@ BITS 32
Flat32SearchForBfvBase:
xor eax, eax
+ mov ecx, 2 ; 2: FFS3 GUID, 1: FFS2 GUID, 0: Not Found
[Ray] 2. Can you map ECX 2 to FFS2 GUID, ECX 3 to FFS3 GUID?
searchingForBfvHeaderLoop:
;
; We check for a firmware volume at every 4KB address in the top 16MB
@@ -32,20 +40,37 @@ searchingForBfvHeaderLoop:
;
sub eax, 0x1000
cmp eax, 0xff000000
- jb searchedForBfvHeaderButNotFound
+ jb searchingForBfvWithOtherFfsGuid
+ cmp ecx, 2
+ jne searchingForFfs2Guid
;
- ; Check FFS GUID
+ ; Check FFS3 GUID
;
- cmp dword [eax + 0x10], FFS_GUID_DWORD0
+ cmp dword [eax + 0x10], FFS3_GUID_DWORD0
jne searchingForBfvHeaderLoop
- cmp dword [eax + 0x14], FFS_GUID_DWORD1
+ cmp dword [eax + 0x14], FFS3_GUID_DWORD1
jne searchingForBfvHeaderLoop
- cmp dword [eax + 0x18], FFS_GUID_DWORD2
+ cmp dword [eax + 0x18], FFS3_GUID_DWORD2
jne searchingForBfvHeaderLoop
- cmp dword [eax + 0x1c], FFS_GUID_DWORD3
+ cmp dword [eax + 0x1c], FFS3_GUID_DWORD3
jne searchingForBfvHeaderLoop
+ jmp checkingFvLength
+searchingForFfs2Guid:
+ ;
+ ; Check FFS2 GUID
+ ;
+ cmp dword [eax + 0x10], FFS2_GUID_DWORD0
+ jne searchingForBfvHeaderLoop
+ cmp dword [eax + 0x14], FFS2_GUID_DWORD1
+ jne searchingForBfvHeaderLoop
+ cmp dword [eax + 0x18], FFS2_GUID_DWORD2
+ jne searchingForBfvHeaderLoop
+ cmp dword [eax + 0x1c], FFS2_GUID_DWORD3
+ jne searchingForBfvHeaderLoop
+
+checkingFvLength:
[Ray] 3. Why is this label added?
;
; Check FV Length
;
@@ -57,6 +82,12 @@ searchingForBfvHeaderLoop:
jmp searchedForBfvHeaderAndItWasFound
+searchingForBfvWithOtherFfsGuid:
+ xor eax, eax
+ dec ecx
+ cmp ecx, 0
+ jne searchingForBfvHeaderLoop
+
searchedForBfvHeaderButNotFound:
;
; Hang if the SEC entry point was not found
--
2.16.2.windows.1
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