diff options
Diffstat (limited to 'src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SelFlatCodeToProtFar16.asm')
| -rw-r--r-- | src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SelFlatCodeToProtFar16.asm | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SelFlatCodeToProtFar16.asm b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SelFlatCodeToProtFar16.asm new file mode 100644 index 00000000..e7734dcb --- /dev/null +++ b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SelFlatCodeToProtFar16.asm @@ -0,0 +1,128 @@ +; $Id: bs3-cmn-SelFlatCodeToProtFar16.asm $ +;; @file +; BS3Kit - Bs3SelFlatCodeToProtFar16. +; + +; +; 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 +; + + +;********************************************************************************************************************************* +;* Header Files * +;********************************************************************************************************************************* +%include "bs3kit-template-header.mac" + + +;********************************************************************************************************************************* +;* External Symbols * +;********************************************************************************************************************************* +BS3_EXTERN_CMN Bs3SelFlatCodeToRealMode +BS3_EXTERN_CMN Bs3SelRealModeCodeToProtMode +TMPL_BEGIN_TEXT + + +;; +; @cproto BS3_CMN_PROTO(uint32_t, Bs3SelRealModeCodeToProtMode,(uint32_t uFlatAddr), false); +; +; @uses Only return registers (ax:dx, eax, eax) +; +BS3_PROC_BEGIN_CMN Bs3SelFlatCodeToProtFar16, BS3_PBC_NEAR + BS3_CALL_CONV_PROLOG 1 + push xBP + mov xBP, xSP + + ; + ; Call Bs3SelFlatCodeToRealMode and then Bs3SelRealModeCodeToProtMode. + ; This avoid some code duplication. + ; +%if TMPL_BITS == 16 + push word [xBP + xCB + cbCurRetAddr + 2] + push word [xBP + xCB + cbCurRetAddr] + call Bs3SelFlatCodeToRealMode + add sp, 4h + + push ax ; save the offset as it will be the same. + + push dx + call Bs3SelRealModeCodeToProtMode + add sp, 2h + + mov dx, ax ; The protected mode selector. + pop ax ; The offset. + +%elif TMPL_BITS == 32 + push dword [xBP + xCB + cbCurRetAddr] + call Bs3SelFlatCodeToRealMode + add esp, 4h + + push eax ; save the result. + + shr eax, 16 + push eax + call Bs3SelRealModeCodeToProtMode + add esp, 4h + + mov [esp + 2], ax ; Update the selector before popping the result. + pop eax + +%elif TMPL_BITS == 64 + push xCX ; Preserve RCX to make the behaviour uniform. + sub xSP, 28h ; 20h bytes of calling convention scratch and 8 byte for saving the result. + + mov ecx, [xBP + xCB + cbCurRetAddr] ; move straight to parameter 0 register. + call Bs3SelFlatCodeToRealMode + + mov [xBP - xCB*2], eax ; Save the result. + + shr eax, 16 + mov ecx, eax ; Move straight to parameter 0 register. + call Bs3SelRealModeCodeToProtMode + + shl eax, 16 ; Shift prot mode selector into result position. + mov ax, [xBP - xCB*2] ; The segment offset from the previous call. + + add xSP, 28h + pop xCX +%else + %error "TMPL_BITS=" TMPL_BITS "!" +%endif + pop xBP + BS3_CALL_CONV_EPILOG 1 + BS3_HYBRID_RET +BS3_PROC_END_CMN Bs3SelFlatCodeToProtFar16 + + +; +; We may be using the near code in some critical code paths, so don't +; penalize it. +; +BS3_CMN_FAR_STUB Bs3SelFlatCodeToProtFar16, 4 + |