projects / mirror_edk2.git / blame
| Commit | Line | Data |
|---|---|---|
| f198e254 AP |
1 | ;------------------------------------------------------------------------------\r |
| 2 | ; @file\r | |
| 3 | ; Search for the Boot Firmware Volume (BFV) base address\r | |
| 4 | ;\r | |
| 5 | ; Copyright (c) 2008 - 2009, Intel Corporation. All rights reserved.<BR>\r | |
| 6 | ; Copyright (c) 2019, Citrix Systems, Inc.\r | |
| 7 | ;\r | |
| 8 | ; SPDX-License-Identifier: BSD-2-Clause-Patent\r | |
| 9 | ;\r | |
| 10 | ;------------------------------------------------------------------------------\r | |
| 11 | \r | |
| 12 | ;#define EFI_FIRMWARE_FILE_SYSTEM2_GUID \\r | |
| 13 | ; { 0x8c8ce578, 0x8a3d, 0x4f1c, { 0x99, 0x35, 0x89, 0x61, 0x85, 0xc3, 0x2d, 0xd3 } }\r | |
| 14 | %define FFS_GUID_DWORD0 0x8c8ce578\r | |
| 15 | %define FFS_GUID_DWORD1 0x4f1c8a3d\r | |
| 16 | %define FFS_GUID_DWORD2 0x61893599\r | |
| 17 | %define FFS_GUID_DWORD3 0xd32dc385\r | |
| 18 | \r | |
| 19 | BITS 32\r | |
| 20 | \r | |
| 21 | ;\r | |
| 22 | ; Modified: EAX, EBX, ECX\r | |
| 23 | ; Preserved: EDI, ESP\r | |
| 24 | ;\r | |
| 25 | ; @param[in] EAX Start search from here\r | |
| 26 | ; @param[out] EBP Address of Boot Firmware Volume (BFV)\r | |
| 27 | ;\r | |
| 28 | Flat32SearchForBfvBase:\r | |
| 29 | \r | |
| 30 | mov ecx, eax\r | |
| 31 | searchingForBfvHeaderLoop:\r | |
| 32 | ;\r | |
| 33 | ; We check for a firmware volume at every 4KB address in the 16MB\r | |
| 34 | ; just below where we started, ECX.\r | |
| 35 | ;\r | |
| 36 | sub eax, 0x1000\r | |
| 37 | mov ebx, ecx\r | |
| 38 | sub ebx, eax\r | |
| 39 | cmp ebx, 0x01000000\r | |
| 40 | ; if ECX-EAX > 16MB; jump notfound\r | |
| 41 | ja searchedForBfvHeaderButNotFound\r | |
| 42 | \r | |
| 43 | ;\r | |
| 44 | ; Check FFS GUID\r | |
| 45 | ;\r | |
| 46 | cmp dword [eax + 0x10], FFS_GUID_DWORD0\r | |
| 47 | jne searchingForBfvHeaderLoop\r | |
| 48 | cmp dword [eax + 0x14], FFS_GUID_DWORD1\r | |
| 49 | jne searchingForBfvHeaderLoop\r | |
| 50 | cmp dword [eax + 0x18], FFS_GUID_DWORD2\r | |
| 51 | jne searchingForBfvHeaderLoop\r | |
| 52 | cmp dword [eax + 0x1c], FFS_GUID_DWORD3\r | |
| 53 | jne searchingForBfvHeaderLoop\r | |
| 54 | \r | |
| 55 | ;\r | |
| 56 | ; Check FV Length\r | |
| 57 | ;\r | |
| 58 | cmp dword [eax + 0x24], 0\r | |
| 59 | jne searchingForBfvHeaderLoop\r | |
| 60 | mov ebx, eax\r | |
| 61 | add ebx, dword [eax + 0x20]\r | |
| 62 | cmp ebx, ecx\r | |
| 63 | jnz searchingForBfvHeaderLoop\r | |
| 64 | \r | |
| 65 | jmp searchedForBfvHeaderAndItWasFound\r | |
| 66 | \r | |
| 67 | searchedForBfvHeaderButNotFound:\r | |
| 68 | ;\r | |
| 69 | ; Hang if the SEC entry point was not found\r | |
| 70 | ;\r | |
| 71 | debugShowPostCode POSTCODE_BFV_NOT_FOUND\r | |
| 72 | \r | |
| 73 | ;\r | |
| 74 | ; 0xbfbfbfbf in the EAX & EBP registers helps signal what failed\r | |
| 75 | ; for debugging purposes.\r | |
| 76 | ;\r | |
| 77 | mov eax, 0xBFBFBFBF\r | |
| 78 | mov ebp, eax\r | |
| 79 | jmp $\r | |
| 80 | \r | |
| 81 | searchedForBfvHeaderAndItWasFound:\r | |
| 82 | mov ebp, eax\r | |
| 83 | \r | |
| 84 | debugShowPostCode POSTCODE_BFV_FOUND\r | |
| 85 | \r | |
| 86 | OneTimeCallRet Flat32SearchForBfvBase\r | |
| 87 | \r |