1 files changed, 103 insertions, 0 deletions
diff --git a/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-MemZero.asm b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-MemZero.asm
new file mode 100644
index 00000000..4e254020
--- /dev/null
+++ b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-MemZero.asm
@@ -0,0 +1,103 @@
+; $Id: bs3-cmn-MemZero.asm $
+;; @file
+; BS3Kit - Bs3MemZero.
+;
+
+;
+; 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"
+
+;;
+; @cproto   BS3_DECL(void) Bs3MemZero_c16(void BS3_FAR *pvDst, size_t cbDst);
+;
+BS3_PROC_BEGIN_CMN Bs3MemZero, BS3_PBC_HYBRID
+%ifdef RT_ARCH_AMD64
+        push    rdi
+
+        mov     rdi, rcx                ; rdi = pvDst
+        mov     rcx, rdx                ; rcx = cbDst
+        shr     rcx, 3                  ; calc qword count.
+        xor     eax, eax                ; rax = 0 (filler qword)
+        cld
+        rep stosq
+
+        mov     rcx, rdx                ; cbDst
+        and     rcx, 7                  ; calc trailing byte count.
+        rep stosb
+
+        pop     rdi
+        BS3_HYBRID_RET
+
+%elif ARCH_BITS == 16
+        push    bp
+        mov     bp, sp
+        push    di
+        push    es
+
+        mov     di, [bp + 2 + cbCurRetAddr]     ; pvDst.off
+        mov     dx, [bp + 2 + cbCurRetAddr + 2] ; pvDst.sel
+        mov     es, dx
+        mov     cx, [bp + 2 + cbCurRetAddr + 4] ; cbDst
+        shr     cx, 1                           ; calc dword count.
+        xor     ax, ax
+        rep stosw
+
+        mov     cx, [bp + 2 + cbCurRetAddr + 4] ; cbDst
+        and     cx, 1                           ; calc tailing byte count.
+        rep stosb
+
+        pop     es
+        pop     di
+        pop     bp
+        BS3_HYBRID_RET
+
+%elif ARCH_BITS == 32
+        push    edi
+
+        mov     edi, [esp + 8]          ; pvDst
+        mov     ecx, [esp + 8 + 4]      ; cbDst
+        shr     cx, 2                   ; calc dword count.
+        xor     eax, eax
+        rep stosd
+
+        mov     ecx, [esp + 8 + 4]      ; cbDst
+        and     ecx, 3                  ; calc tailing byte count.
+        rep stosb
+
+        pop     edi
+        BS3_HYBRID_RET
+
+%else
+ %error "Unknown bitness."
+%endif
+BS3_PROC_END_CMN   Bs3MemZero
+