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Diffstat (limited to '')
-rw-r--r-- | src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SelFlatDataToRealMode.asm | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SelFlatDataToRealMode.asm b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SelFlatDataToRealMode.asm new file mode 100644 index 00000000..cb142e80 --- /dev/null +++ b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-SelFlatDataToRealMode.asm @@ -0,0 +1,104 @@ +; $Id: bs3-cmn-SelFlatDataToRealMode.asm $ +;; @file +; BS3Kit - Bs3SelFlatDataToRealMode +; + +; +; 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 * +;********************************************************************************************************************************* +%ifdef BS3_STRICT +BS3_EXTERN_CMN Bs3Panic +%endif +TMPL_BEGIN_TEXT +%if TMPL_BITS == 16 +CPU 8086 +%endif + + +;; +; @cproto BS3_CMN_PROTO_NOSB(uint32_t, Bs3SelFlatDataToRealMode,(uint32_t uFlatAddr)); +; +; @uses Only return registers (ax:dx, eax, eax) +; @remarks No 20h scratch area requirements. +; +BS3_PROC_BEGIN_CMN Bs3SelFlatDataToRealMode, BS3_PBC_NEAR ; Far stub generated by the makefile/bs3kit.h. + push xBP + mov xBP, xSP + + ; + ; Take the simplest approach possible (64KB tiled). + ; +%if TMPL_BITS == 16 + mov ax, cx ; save cx + mov dx, [xBP + xCB + cbCurRetAddr + 2] + %ifdef BS3_STRICT + cmp dx, _1M >> 16 + jb .address_ok + call Bs3Panic +.address_ok: + %endif + mov cl, 12 + shl dx, cl + mov ax, cx ; restore cx + + mov ax, [xBP + xCB + cbCurRetAddr] + +%else + %if TMPL_BITS == 32 + mov eax, [xBP + xCB + cbCurRetAddr] + %else + mov rax, rcx + %endif + %ifdef BS3_STRICT + cmp xAX, _1M + jb .address_ok + call Bs3Panic +.address_ok: + %endif + ror eax, 16 + shl ax, 12 + rol eax, 16 +%endif + + pop xBP + BS3_HYBRID_RET +BS3_PROC_END_CMN Bs3SelFlatDataToRealMode + |