diff --git a/OvmfPkg/ResetVector/Ia16/ResetVectorVtf0.asm b/OvmfPkg/ResetVector/Ia16/ResetVectorVtf0.asm new file mode 100644 index 0000000000..980e0138e7 --- /dev/null +++ b/OvmfPkg/ResetVector/Ia16/ResetVectorVtf0.asm @@ -0,0 +1,100 @@ +;------------------------------------------------------------------------------ +; @file +; First code executed by processor after resetting. +; Derived from UefiCpuPkg/ResetVector/Vtf0/Ia16/ResetVectorVtf0.asm +; +; Copyright (c) 2008 - 2014, Intel Corporation. All rights reserved.
+; SPDX-License-Identifier: BSD-2-Clause-Patent +; +;------------------------------------------------------------------------------ + +BITS 16 + +ALIGN 16 + +; +; Pad the image size to 4k when page tables are in VTF0 +; +; If the VTF0 image has page tables built in, then we need to make +; sure the end of VTF0 is 4k above where the page tables end. +; +; This is required so the page tables will be 4k aligned when VTF0 is +; located just below 0x100000000 (4GB) in the firmware device. +; +%ifdef ALIGN_TOP_TO_4K_FOR_PAGING + TIMES (0x1000 - ($ - EndOfPageTables) - 0x20) DB 0 +%endif + +; +; SEV-ES Processor Reset support +; +; sevEsResetBlock: +; For the initial boot of an AP under SEV-ES, the "reset" RIP must be +; programmed to the RAM area defined by SEV_ES_AP_RESET_IP. A known offset +; and GUID will be used to locate this block in the firmware and extract +; the build time RIP value. The GUID must always be 48 bytes from the +; end of the firmware. +; +; 0xffffffca (-0x36) - IP value +; 0xffffffcc (-0x34) - CS segment base [31:16] +; 0xffffffce (-0x32) - Size of the SEV-ES reset block +; 0xffffffd0 (-0x30) - SEV-ES reset block GUID +; (00f771de-1a7e-4fcb-890e-68c77e2fb44e) +; +; A hypervisor reads the CS segement base and IP value. The CS segment base +; value represents the high order 16-bits of the CS segment base, so the +; hypervisor must left shift the value of the CS segement base by 16 bits to +; form the full CS segment base for the CS segment register. It would then +; program the EIP register with the IP value as read. +; + +TIMES (32 - (sevEsResetBlockEnd - sevEsResetBlockStart)) DB 0 + +sevEsResetBlockStart: + DD SEV_ES_AP_RESET_IP + DW sevEsResetBlockEnd - sevEsResetBlockStart + DB 0xDE, 0x71, 0xF7, 0x00, 0x7E, 0x1A, 0xCB, 0x4F + DB 0x89, 0x0E, 0x68, 0xC7, 0x7E, 0x2F, 0xB4, 0x4E +sevEsResetBlockEnd: + +ALIGN 16 + +applicationProcessorEntryPoint: +; +; Application Processors entry point +; +; GenFv generates code aligned on a 4k boundary which will jump to this +; location. (0xffffffe0) This allows the Local APIC Startup IPI to be +; used to wake up the application processors. +; + jmp EarlyApInitReal16 + +ALIGN 8 + + DD 0 + +; +; The VTF signature +; +; VTF-0 means that the VTF (Volume Top File) code does not require +; any fixups. +; +vtfSignature: + DB 'V', 'T', 'F', 0 + +ALIGN 16 + +resetVector: +; +; Reset Vector +; +; This is where the processor will begin execution +; + nop + nop + jmp EarlyBspInitReal16 + +ALIGN 16 + +fourGigabytes: + diff --git a/OvmfPkg/ResetVector/ResetVector.nasmb b/OvmfPkg/ResetVector/ResetVector.nasmb index 762661115d..4913b379a9 100644 --- a/OvmfPkg/ResetVector/ResetVector.nasmb +++ b/OvmfPkg/ResetVector/ResetVector.nasmb @@ -82,5 +82,6 @@ %include "Main.asm" + %define SEV_ES_AP_RESET_IP FixedPcdGet32 (PcdSevEsWorkAreaBase) %include "Ia16/ResetVectorVtf0.asm"