projects / mirror_edk2.git / blame
| Commit | Line | Data |
|---|---|---|
| a8c791c1 AP |
1 | ;------------------------------------------------------------------------------\r |
| 2 | ; @file\r | |
| 3 | ; An entry point use by Xen when a guest is started in PVH mode.\r | |
| 4 | ;\r | |
| 5 | ; Copyright (c) 2019, Citrix Systems, Inc.\r | |
| 6 | ;\r | |
| 7 | ; SPDX-License-Identifier: BSD-2-Clause-Patent\r | |
| 8 | ;\r | |
| 9 | ;------------------------------------------------------------------------------\r | |
| 10 | \r | |
| 11 | BITS 32\r | |
| 12 | \r | |
| 13 | xenPVHMain:\r | |
| 14 | ;\r | |
| 15 | ; 'BP' to indicate boot-strap processor\r | |
| 16 | ;\r | |
| 17 | mov di, 'BP'\r | |
| 18 | \r | |
| 93314ae5 AP |
19 | ;\r |
| 20 | ; Store "Start of day" struct pointer for later use\r | |
| 21 | ;\r | |
| 22 | mov dword[PVH_SPACE (0)], ebx\r | |
| 23 | mov dword[PVH_SPACE (4)], 'XPVH'\r | |
| 24 | \r | |
| f198e254 AP |
25 | ;\r |
| 26 | ; calculate delta between build-addr and run position\r | |
| 27 | ;\r | |
| 28 | mov esp, PVH_SPACE(16) ; create a temporary stack\r | |
| 29 | call .delta\r | |
| 30 | .delta:\r | |
| 31 | pop edx ; get addr of .delta\r | |
| 32 | sub edx, ADDR_OF(.delta) ; calculate delta\r | |
| 33 | \r | |
| 34 | ;\r | |
| 35 | ; Find address of GDT and gdtr and fix the later\r | |
| 36 | ;\r | |
| a8c791c1 | 37 | mov ebx, ADDR_OF(gdtr)\r |
| f198e254 AP |
38 | add ebx, edx ; add delta gdtr\r |
| 39 | mov eax, ADDR_OF(GDT_BASE)\r | |
| 40 | add eax, edx ; add delta to GDT_BASE\r | |
| 41 | mov dword[ebx + 2], eax ; fix GDT_BASE addr in gdtr\r | |
| a8c791c1 AP |
42 | lgdt [ebx]\r |
| 43 | \r | |
| 44 | mov eax, SEC_DEFAULT_CR0\r | |
| 45 | mov cr0, eax\r | |
| 46 | \r | |
| f198e254 AP |
47 | ;\r |
| 48 | ; push return addr to the stack, then return far\r | |
| 49 | ;\r | |
| 50 | push dword LINEAR_CODE_SEL ; segment to select\r | |
| 51 | mov eax, ADDR_OF(.jmpToNewCodeSeg) ; return addr\r | |
| 52 | add eax, edx ; add delta to return addr\r | |
| 53 | push eax\r | |
| 54 | retf\r | |
| a8c791c1 AP |
55 | .jmpToNewCodeSeg:\r |
| 56 | \r | |
| 57 | mov eax, SEC_DEFAULT_CR4\r | |
| 58 | mov cr4, eax\r | |
| 59 | \r | |
| 60 | mov ax, LINEAR_SEL\r | |
| 61 | mov ds, ax\r | |
| 62 | mov es, ax\r | |
| 63 | mov fs, ax\r | |
| 64 | mov gs, ax\r | |
| 65 | mov ss, ax\r | |
| 66 | \r | |
| f198e254 AP |
67 | ;\r |
| 68 | ; ESP will be used as initial value of the EAX register\r | |
| 69 | ; in Main.asm\r | |
| 70 | ;\r | |
| 71 | xor esp, esp\r | |
| 72 | \r | |
| 73 | ;\r | |
| 74 | ; parameter for Flat32SearchForBfvBase\r | |
| 75 | ;\r | |
| 29280c70 | 76 | mov eax, 0 ; ADDR_OF(fourGigabytes)\r |
| f198e254 AP |
77 | add eax, edx ; add delta\r |
| 78 | \r | |
| a8c791c1 AP |
79 | ;\r |
| 80 | ; Jump to the main routine of the pre-SEC code\r | |
| 81 | ; skiping the 16-bit part of the routine and\r | |
| 82 | ; into the 32-bit flat mode part\r | |
| 83 | ;\r | |
| 84 | OneTimeCallRet TransitionFromReal16To32BitFlat\r |