OvmfPkg/ResetVector: convert SEV-ES Reset Block structure to be GUIDed

[mirror_edk2.git] / OvmfPkg / ResetVector / Ia16 / ResetVectorVtf0.asm

;------------------------------------------------------------------------------\r
; @file\r
; First code executed by processor after resetting.\r
; Derived from UefiCpuPkg/ResetVector/Vtf0/Ia16/ResetVectorVtf0.asm\r
;\r
; Copyright (c) 2008 - 2014, Intel Corporation. All rights reserved.<BR>\r
; SPDX-License-Identifier: BSD-2-Clause-Patent\r
;\r
;------------------------------------------------------------------------------\r
\r
BITS    16\r
\r
ALIGN   16\r
\r
;\r
; Pad the image size to 4k when page tables are in VTF0\r
;\r
; If the VTF0 image has page tables built in, then we need to make\r
; sure the end of VTF0 is 4k above where the page tables end.\r
;\r
; This is required so the page tables will be 4k aligned when VTF0 is\r
; located just below 0x100000000 (4GB) in the firmware device.\r
;\r
%ifdef ALIGN_TOP_TO_4K_FOR_PAGING\r
    TIMES (0x1000 - ($ - EndOfPageTables) - 0x20) DB 0\r
%endif\r
\r
;\r
; Padding to ensure first guid starts at 0xffffffd0\r
;\r
TIMES (15 - ((guidedStructureEnd - guidedStructureStart + 15) % 16)) DB 0\r
\r
; GUIDed structure.  To traverse this you should first verify the\r
; presence of the table footer guid\r
; (96b582de-1fb2-45f7-baea-a366c55a082d) at 0xffffffd0.  If that\r
; is found, the two bytes at 0xffffffce are the entire table length.\r
;\r
; The table is composed of structures with the form:\r
;\r
; Data (arbitrary bytes identified by guid)\r
; length from start of data to end of guid (2 bytes)\r
; guid (16 bytes)\r
;\r
; so work back from the footer using the length to traverse until you\r
; either find the guid you're looking for or run off the beginning of\r
; the table.\r
;\r
guidedStructureStart:\r
\r
;\r
; SEV-ES Processor Reset support\r
;\r
; sevEsResetBlock:\r
;   For the initial boot of an AP under SEV-ES, the "reset" RIP must be\r
;   programmed to the RAM area defined by SEV_ES_AP_RESET_IP. The data\r
;   format is:\r
;\r
;   IP value [0:15]\r
;   CS segment base [31:16]\r
;\r
;   GUID (SEV-ES reset block): 00f771de-1a7e-4fcb-890e-68c77e2fb44e\r
;\r
;   A hypervisor reads the CS segement base and IP value. The CS segment base\r
;   value represents the high order 16-bits of the CS segment base, so the\r
;   hypervisor must left shift the value of the CS segement base by 16 bits to\r
;   form the full CS segment base for the CS segment register. It would then\r
;   program the EIP register with the IP value as read.\r
;\r
\r
sevEsResetBlockStart:\r
    DD      SEV_ES_AP_RESET_IP\r
    DW      sevEsResetBlockEnd - sevEsResetBlockStart\r
    DB      0xDE, 0x71, 0xF7, 0x00, 0x7E, 0x1A, 0xCB, 0x4F\r
    DB      0x89, 0x0E, 0x68, 0xC7, 0x7E, 0x2F, 0xB4, 0x4E\r
sevEsResetBlockEnd:\r
\r
;\r
; Table footer:\r
;\r
; length of whole table (16 bit word)\r
; GUID (table footer): 96b582de-1fb2-45f7-baea-a366c55a082d\r
;\r
    DW      guidedStructureEnd - guidedStructureStart\r
    DB      0xDE, 0x82, 0xB5, 0x96, 0xB2, 0x1F, 0xF7, 0x45\r
    DB      0xBA, 0xEA, 0xA3, 0x66, 0xC5, 0x5A, 0x08, 0x2D\r
\r
guidedStructureEnd:\r
\r
ALIGN   16\r
\r
applicationProcessorEntryPoint:\r
;\r
; Application Processors entry point\r
;\r
; GenFv generates code aligned on a 4k boundary which will jump to this\r
; location.  (0xffffffe0)  This allows the Local APIC Startup IPI to be\r
; used to wake up the application processors.\r
;\r
    jmp     EarlyApInitReal16\r
\r
ALIGN   8\r
\r
    DD      0\r
\r
;\r
; The VTF signature\r
;\r
; VTF-0 means that the VTF (Volume Top File) code does not require\r
; any fixups.\r
;\r
vtfSignature:\r
    DB      'V', 'T', 'F', 0\r
\r
ALIGN   16\r
\r
resetVector:\r
;\r
; Reset Vector\r
;\r
; This is where the processor will begin execution\r
;\r
    nop\r
    nop\r
    jmp     EarlyBspInitReal16\r
\r
ALIGN   16\r
\r
fourGigabytes:\r
\r