diff options
Diffstat (limited to 'src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SwitchHlpConvProtModeRetfPopBpDecBpAndReturn.asm')
| -rw-r--r-- | src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SwitchHlpConvProtModeRetfPopBpDecBpAndReturn.asm | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SwitchHlpConvProtModeRetfPopBpDecBpAndReturn.asm b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SwitchHlpConvProtModeRetfPopBpDecBpAndReturn.asm new file mode 100644 index 00000000..223e95e6 --- /dev/null +++ b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SwitchHlpConvProtModeRetfPopBpDecBpAndReturn.asm @@ -0,0 +1,126 @@ +; $Id: bs3-cmn-SwitchHlpConvProtModeRetfPopBpDecBpAndReturn.asm $ +;; @file +; BS3Kit - Bs3SwitchToPP32 +; + +; +; Copyright (C) 2007-2023 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" + + +%if TMPL_BITS == 16 +BS3_EXTERN_CMN Bs3SelProtModeCodeToRealMode +%else +BS3_EXTERN_CMN Bs3SelFar32ToFlat32 +%endif + + +;; +; SwitchToXxx helper that converts a 16-bit protected mode far return +; into something suitable for the current mode and performs the return. +; +; The caller jmps to this routine. The stack holds an incremented BP (odd is +; far indicator) and a 16-bit far return address. +; +; @uses Nothing. +; @remarks 16-bit ASSUMES we're returning to protected mode!! +; +%if TMPL_BITS == 16 +BS3_BEGIN_TEXT16_FARSTUBS +%endif +BS3_PROC_BEGIN_CMN Bs3SwitchHlpConvProtModeRetfPopBpDecBpAndReturn, BS3_PBC_NEAR +%if TMPL_BITS == 16 + ; Convert the selector of the 16:16 protected mode return address to the + ; corresponding 16-bit real mode segment. + push ax + + mov ax, [bp + 2 + 2] + push ax + call Bs3SelProtModeCodeToRealMode ; This doesn't trash any registers (except AX). + add sp, 2 + mov [bp + 2 + 2], ax + + pop ax + + pop bp + dec bp + retf + +%elif TMPL_BITS == 32 + push eax + push ecx + push edx + + movzx eax, word [esp + 4*3 + 2] ; return offset + movzx edx, word [esp + 4*3 + 2 + 2] ; return selector + push eax + push edx + call Bs3SelFar32ToFlat32 + add esp, 8 + mov [esp + 4*3 + 2], eax + + pop edx + pop ecx + pop eax + pop bp + dec bp + ret +%else + push rax + push rcx + push rdx + push r8 + push r9 + push r10 + push r11 + + movzx ecx, word [rsp + 8*7 + 2] ; return offset + movzx edx, word [rsp + 8*7 + 2 + 2] ; return selector + sub rsp, 20h + call Bs3SelFar32ToFlat32 + add rsp, 20h + mov [rsp + 8*7 + 2], eax + + pop r11 + pop r10 + pop r9 + pop r8 + pop rdx + pop rcx + pop rax + mov bp, [rsp] + add rsp, 2h + dec bp + o32 ret +%endif +BS3_PROC_END_CMN Bs3SwitchHlpConvProtModeRetfPopBpDecBpAndReturn + |