/* $Id: bs3-cmn-RegCtxGetRspSsAsCurPtr.c $ */
/** @file
 * BS3Kit - Bs3RegCtxGetRspSsAsCurPtr
 */

/*
 * 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.h"


#undef Bs3RegCtxGetRspSsAsCurPtr
BS3_CMN_DEF(void BS3_FAR *, Bs3RegCtxGetRspSsAsCurPtr,(PBS3REGCTX pRegCtx))
{
    uint64_t uFlat;
    if (BS3_MODE_IS_RM_OR_V86(pRegCtx->bMode))
    {
#if ARCH_BITS == 16
        if (BS3_MODE_IS_RM_OR_V86(g_bBs3CurrentMode))
            return BS3_FP_MAKE(pRegCtx->ss, pRegCtx->rsp.u16);
#endif
        uFlat = ((uint32_t)pRegCtx->ss << 4) + pRegCtx->rsp.u16;
    }
    else if (!BS3_MODE_IS_64BIT_CODE(pRegCtx->bMode))
        uFlat = Bs3SelFar32ToFlat32(pRegCtx->rsp.u32, pRegCtx->ss);
    else
        uFlat = pRegCtx->rsp.u64;

#if ARCH_BITS == 16
    if (uFlat >= (BS3_MODE_IS_RM_OR_V86(g_bBs3CurrentMode) ? _1M : BS3_SEL_TILED_AREA_SIZE))
        return NULL;
    return BS3_FP_MAKE(Bs3Sel16HighFlatPtrToSelector((uint32_t)uFlat >> 16), (uint16_t)uFlat);
#else
    /* Typically no need to check limit in 32-bit mode, because 64-bit mode
       just repeats the first 4GB for the rest of the address space. */
    return (void *)(uintptr_t)uFlat;
#endif
}