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Diffstat (limited to 'src/VBox/ValidationKit/bootsectors/bs3kit/bs3-mode-SwitchToLM64.asm')
| -rw-r--r-- | src/VBox/ValidationKit/bootsectors/bs3kit/bs3-mode-SwitchToLM64.asm | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-mode-SwitchToLM64.asm b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-mode-SwitchToLM64.asm new file mode 100644 index 00000000..2d314332 --- /dev/null +++ b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-mode-SwitchToLM64.asm @@ -0,0 +1,114 @@ +; $Id: bs3-mode-SwitchToLM64.asm $ +;; @file +; BS3Kit - Bs3SwitchToLM64 +; + +; +; Copyright (C) 2007-2022 Oracle and/or its affiliates. +; +; This file is part of VirtualBox base platform packages, as +; available from https://www.virtualbox.org. +; +; This program is free software; you can redistribute it and/or +; modify it under the terms of the GNU General Public License +; as published by the Free Software Foundation, in version 3 of the +; License. +; +; This program is distributed in the hope that it will be useful, but +; WITHOUT ANY WARRANTY; without even the implied warranty of +; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +; General Public License for more details. +; +; You should have received a copy of the GNU General Public License +; along with this program; if not, see <https://www.gnu.org/licenses>. +; +; The contents of this file may alternatively be used under the terms +; of the Common Development and Distribution License Version 1.0 +; (CDDL), a copy of it is provided in the "COPYING.CDDL" file included +; in the VirtualBox distribution, in which case the provisions of the +; CDDL are applicable instead of those of the GPL. +; +; You may elect to license modified versions of this file under the +; terms and conditions of either the GPL or the CDDL or both. +; +; SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 +; + +%include "bs3kit-template-header.mac" + + +;; +; Switch to 64-bit long mode from any other mode. +; +; @cproto BS3_DECL(void) Bs3SwitchToLM64(void); +; +; @uses Nothing (except possibly high 32-bit and/or upper 64-bit register parts). +; +; @remarks Obviously returns to 64-bit mode, even if the caller was in 16-bit +; or 32-bit mode. It doesn't not preserve the callers ring, but +; instead changes to ring-0. +; +; @remarks Does not require 20h of parameter scratch space in 64-bit mode. +; +BS3_GLOBAL_NAME_EX TMPL_NM(Bs3SwitchToLM64_Safe), function, 0 +BS3_PROC_BEGIN_MODE Bs3SwitchToLM64, BS3_PBC_NEAR +%ifdef TMPL_LM64 + ret + +%elifdef TMPL_CMN_LM + ; + ; Already in long mode, just switch to 64-bit. + ; + extern BS3_CMN_NM(Bs3SwitchTo64Bit) + jmp BS3_CMN_NM(Bs3SwitchTo64Bit) + +%else + ; + ; Switch to LM32 and then switch to 64-bits (IDT & TSS are the same for + ; LM16, LM32 and LM64, unlike the rest). + ; + ; (The long mode switching code is going via 32-bit protected mode, so + ; Bs3SwitchToLM32 contains the actual code for switching to avoid + ; unnecessary 32-bit -> 64-bit -> 32-bit trips.) + ; + %ifdef TMPL_16BIT + and esp, 0ffffh + push word [esp] ; copy return address. + and word [esp + 2], 0 ; clear upper return address + add dword [esp], BS3_ADDR_BS3TEXT16 ; Add base of return segment, completing 32-bit conversion. + %endif + extern TMPL_NM(Bs3SwitchToLM32) + call TMPL_NM(Bs3SwitchToLM32) + BS3_SET_BITS 32 + + extern _Bs3SwitchTo64Bit_c32 + jmp _Bs3SwitchTo64Bit_c32 +%endif +BS3_PROC_END_MODE Bs3SwitchToLM64 + + +%if TMPL_BITS == 16 +;; +; Custom far stub. +BS3_BEGIN_TEXT16_FARSTUBS +BS3_PROC_BEGIN_MODE Bs3SwitchToLM64, BS3_PBC_FAR + inc bp + push bp + mov bp, sp + + ; Call the real thing. + call TMPL_NM(Bs3SwitchToLM64) + BS3_SET_BITS 64 + + ; Jmp to common code for the tedious conversion. + %if BS3_MODE_IS_RM_OR_V86(TMPL_MODE) + extern _Bs3SwitchHlpConvRealModeRetfPopBpDecBpAndReturn_c64 + jmp _Bs3SwitchHlpConvRealModeRetfPopBpDecBpAndReturn_c64 + %else + extern _Bs3SwitchHlpConvProtModeRetfPopBpDecBpAndReturn_c64 + jmp _Bs3SwitchHlpConvProtModeRetfPopBpDecBpAndReturn_c64 + %endif + BS3_SET_BITS 16 +BS3_PROC_END_MODE Bs3SwitchToLM64 +%endif + |