1 files changed, 99 insertions, 0 deletions
diff --git a/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-c16-SwitchFromV86To16BitAndCallC.asm b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-c16-SwitchFromV86To16BitAndCallC.asm
new file mode 100644
index 00000000..b723178e
--- /dev/null
+++ b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-c16-SwitchFromV86To16BitAndCallC.asm
@@ -0,0 +1,99 @@
+; $Id: bs3-c16-SwitchFromV86To16BitAndCallC.asm $
+;; @file
+; BS3Kit - Bs3SwitchFromV86To16BitAndCallC
+;
+
+;
+; Copyright (C) 2007-2019 Oracle Corporation
+;
+; This file is part of VirtualBox Open Source Edition (OSE), as
+; available from http://www.virtualbox.org. This file is free software;
+; you can redistribute it and/or modify it under the terms of the GNU
+; General Public License (GPL) as published by the Free Software
+; Foundation, in version 2 as it comes in the "COPYING" file of the
+; VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+; hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+;
+; The contents of this file may alternatively be used under the terms
+; of the Common Development and Distribution License Version 1.0
+; (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+; VirtualBox OSE 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.
+;
+
+;*********************************************************************************************************************************
+;*  Header Files                                                                                                                 *
+;*********************************************************************************************************************************
+%include "bs3kit-template-header.mac"
+%if TMPL_BITS != 16
+ %error "16-bit only"
+%endif
+
+
+;*********************************************************************************************************************************
+;*  External Symbols                                                                                                             *
+;*********************************************************************************************************************************
+%ifdef BS3_STRICT
+BS3_EXTERN_DATA16 g_bBs3CurrentMode
+TMPL_BEGIN_TEXT
+BS3_EXTERN_CMN    Bs3Panic
+%endif
+BS3_EXTERN_CMN    Bs3SwitchTo16Bit
+BS3_EXTERN_CMN    Bs3SwitchTo16BitV86
+BS3_EXTERN_CMN    Bs3SelRealModeCodeToProtMode
+
+
+;;
+; @cproto   BS3_CMN_PROTO_STUB(int, Bs3SwitchFromV86To16BitAndCallC,(FPFNBS3FAR fpfnCall, unsigned cbParams, ...));
+;
+BS3_PROC_BEGIN_CMN Bs3SwitchFromV86To16BitAndCallC, BS3_PBC_HYBRID
+        inc     bp
+        push    bp
+        mov     bp, sp
+
+        ;
+        ; Push the arguments first.
+        ;
+        mov     ax, si                  ; save si
+        mov     si, [bp + 2 + cbCurRetAddr + 4]
+%ifdef BS3_STRICT
+        test    si, 1
+        jz      .cbParams_ok
+        call    Bs3Panic
+.cbParams_ok:
+        test    byte [g_bBs3CurrentMode], BS3_MODE_CODE_V86
+        jnz     .mode_ok
+        call    Bs3Panic
+.mode_ok:
+%endif
+
+.push_more:
+        push    word [bp + 2 + cbCurRetAddr + 4 + 2 + si - 2]
+        sub     si, 2
+        jnz     .push_more
+        mov     si, ax                  ; restore si
+
+        ;
+        ; Convert the code segment to a 16-bit prot mode selector
+        ;
+        push    word [bp + 2 + cbCurRetAddr + 2]
+        call    Bs3SelRealModeCodeToProtMode
+        mov     [bp + 2 + cbCurRetAddr + 2], ax
+        add     sp, 2
+
+        ;
+        ; Switch mode.
+        ;
+        call    Bs3SwitchTo16Bit
+        call far [bp + 2 + cbCurRetAddr]
+        call    Bs3SwitchTo16BitV86
+
+        mov     sp, bp
+        pop     bp
+        dec     bp
+        BS3_HYBRID_RET
+BS3_PROC_END_CMN   Bs3SwitchFromV86To16BitAndCallC
+