diff options
Diffstat (limited to 'src/VBox/Devices/EFI/Firmware/UefiCpuPkg/ResetVector/Vtf0/Ia32/SearchForSecEntry.asm')
-rw-r--r-- | src/VBox/Devices/EFI/Firmware/UefiCpuPkg/ResetVector/Vtf0/Ia32/SearchForSecEntry.asm | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/src/VBox/Devices/EFI/Firmware/UefiCpuPkg/ResetVector/Vtf0/Ia32/SearchForSecEntry.asm b/src/VBox/Devices/EFI/Firmware/UefiCpuPkg/ResetVector/Vtf0/Ia32/SearchForSecEntry.asm new file mode 100644 index 00000000..53826507 --- /dev/null +++ b/src/VBox/Devices/EFI/Firmware/UefiCpuPkg/ResetVector/Vtf0/Ia32/SearchForSecEntry.asm @@ -0,0 +1,194 @@ +;------------------------------------------------------------------------------ +; @file +; Search for the SEC Core entry point +; +; Copyright (c) 2008 - 2011, Intel Corporation. All rights reserved.<BR> +; SPDX-License-Identifier: BSD-2-Clause-Patent +; +;------------------------------------------------------------------------------ + +BITS 32 + +%define EFI_FV_FILETYPE_SECURITY_CORE 0x03 + +; +; Modified: EAX, EBX, ECX, EDX +; Preserved: EDI, EBP, ESP +; +; @param[in] EBP Address of Boot Firmware Volume (BFV) +; @param[out] ESI SEC Core Entry Point Address +; +Flat32SearchForSecEntryPoint: + + ; + ; Initialize EBP and ESI to 0 + ; + xor ebx, ebx + mov esi, ebx + + ; + ; Pass over the BFV header + ; + mov eax, ebp + mov bx, [ebp + 0x30] + add eax, ebx + jc secEntryPointWasNotFound + + jmp searchingForFfsFileHeaderLoop + +moveForwardWhileSearchingForFfsFileHeaderLoop: + ; + ; Make forward progress in the search + ; + inc eax + jc secEntryPointWasNotFound + +searchingForFfsFileHeaderLoop: + test eax, eax + jz secEntryPointWasNotFound + + ; + ; Ensure 8 byte alignment + ; + add eax, 7 + jc secEntryPointWasNotFound + and al, 0xf8 + + ; + ; Look to see if there is an FFS file at eax + ; + mov bl, [eax + 0x17] + test bl, 0x20 + jz moveForwardWhileSearchingForFfsFileHeaderLoop + mov ecx, [eax + 0x14] + and ecx, 0x00ffffff + or ecx, ecx + jz moveForwardWhileSearchingForFfsFileHeaderLoop + add ecx, eax + jz jumpSinceWeFoundTheLastFfsFile + jc moveForwardWhileSearchingForFfsFileHeaderLoop +jumpSinceWeFoundTheLastFfsFile: + + ; + ; There seems to be a valid file at eax + ; + cmp byte [eax + 0x12], EFI_FV_FILETYPE_SECURITY_CORE ; Check File Type + jne readyToTryFfsFileAtEcx + +fileTypeIsSecCore: + OneTimeCall GetEntryPointOfFfsFile + test eax, eax + jnz doneSeachingForSecEntryPoint + +readyToTryFfsFileAtEcx: + ; + ; Try the next FFS file at ECX + ; + mov eax, ecx + jmp searchingForFfsFileHeaderLoop + +secEntryPointWasNotFound: + xor eax, eax + +doneSeachingForSecEntryPoint: + mov esi, eax + + test esi, esi + jnz secCoreEntryPointWasFound + +secCoreEntryPointWasNotFound: + ; + ; Hang if the SEC entry point was not found + ; + debugShowPostCode POSTCODE_SEC_NOT_FOUND + jz $ + +secCoreEntryPointWasFound: + debugShowPostCode POSTCODE_SEC_FOUND + + OneTimeCallRet Flat32SearchForSecEntryPoint + +%define EFI_SECTION_PE32 0x10 +%define EFI_SECTION_TE 0x12 + +; +; Input: +; EAX - Start of FFS file +; ECX - End of FFS file +; +; Output: +; EAX - Entry point of PE32 (or 0 if not found) +; +; Modified: +; EBX +; +GetEntryPointOfFfsFile: + test eax, eax + jz getEntryPointOfFfsFileErrorReturn + add eax, 0x18 ; EAX = Start of section + +getEntryPointOfFfsFileLoopForSections: + cmp eax, ecx + jae getEntryPointOfFfsFileErrorReturn + + cmp byte [eax + 3], EFI_SECTION_PE32 + je getEntryPointOfFfsFileFoundPe32Section + + cmp byte [eax + 3], EFI_SECTION_TE + je getEntryPointOfFfsFileFoundTeSection + + ; + ; The section type was not PE32 or TE, so move to next section + ; + mov ebx, dword [eax] + and ebx, 0x00ffffff + add eax, ebx + jc getEntryPointOfFfsFileErrorReturn + + ; + ; Ensure that FFS section is 32-bit aligned + ; + add eax, 3 + jc getEntryPointOfFfsFileErrorReturn + and al, 0xfc + jmp getEntryPointOfFfsFileLoopForSections + +getEntryPointOfFfsFileFoundPe32Section: + add eax, 4 ; EAX = Start of PE32 image + + cmp word [eax], 'MZ' + jne getEntryPointOfFfsFileErrorReturn + movzx ebx, word [eax + 0x3c] + add ebx, eax + + ; if (Hdr.Pe32->Signature == EFI_IMAGE_NT_SIGNATURE) + cmp dword [ebx], `PE\x00\x00` + jne getEntryPointOfFfsFileErrorReturn + + ; *EntryPoint = (VOID *)((UINTN)Pe32Data + + ; (UINTN)(Hdr.Pe32->OptionalHeader.AddressOfEntryPoint & 0x0ffffffff)); + add eax, [ebx + 0x4 + 0x14 + 0x10] + jmp getEntryPointOfFfsFileReturn + +getEntryPointOfFfsFileFoundTeSection: + add eax, 4 ; EAX = Start of TE image + mov ebx, eax + + ; if (Hdr.Te->Signature == EFI_TE_IMAGE_HEADER_SIGNATURE) + cmp word [ebx], 'VZ' + jne getEntryPointOfFfsFileErrorReturn + ; *EntryPoint = (VOID *)((UINTN)Pe32Data + + ; (UINTN)(Hdr.Te->AddressOfEntryPoint & 0x0ffffffff) + + ; sizeof(EFI_TE_IMAGE_HEADER) - Hdr.Te->StrippedSize); + add eax, [ebx + 0x8] + add eax, 0x28 + movzx ebx, word [ebx + 0x6] + sub eax, ebx + jmp getEntryPointOfFfsFileReturn + +getEntryPointOfFfsFileErrorReturn: + mov eax, 0 + +getEntryPointOfFfsFileReturn: + OneTimeCallRet GetEntryPointOfFfsFile + |