1 files changed, 89 insertions, 0 deletions
diff --git a/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-MemCmp.asm b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-MemCmp.asm
new file mode 100644
index 00000000..86fd52f6
--- /dev/null
+++ b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-MemCmp.asm
@@ -0,0 +1,89 @@
+; $Id: bs3-cmn-MemCmp.asm $
+;; @file
+; BS3Kit - Bs3MemCmp.
+;
+
+;
+; 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.
+;
+
+%include "bs3kit-template-header.mac"
+
+;;
+; @cproto   BS3_CMN_PROTO_NOSB(int, Bs3MemCmp,(void const BS3_FAR *pv1, void const BS3_FAR *pv2, size_t cb));
+;
+BS3_PROC_BEGIN_CMN Bs3MemCmp, BS3_PBC_HYBRID
+TONLY16 CPU 8086
+        push    xBP
+        mov     xBP, xSP
+        push    xDI
+        push    xSI
+TNOT64  push    es
+TONLY16 push    ds
+        cld
+
+        ;
+        ; To save complexity and space, do straight forward byte compares.
+        ;
+%if TMPL_BITS == 16
+        mov     di, [bp + 2 + cbCurRetAddr]         ; pv1.off
+        mov     es, [bp + 2 + cbCurRetAddr + 2]     ; pv1.sel
+        mov     si, [bp + 2 + cbCurRetAddr + 4]     ; pv2.off
+        mov     ds, [bp + 2 + cbCurRetAddr + 6]     ; pv2.sel
+        mov     cx, [bp + 2 + cbCurRetAddr + 8]     ; cbDst
+        xor     ax, ax
+        repe cmpsb
+        je      .return
+
+        mov     al, [es:di - 1]
+        xor     dx, dx
+        mov     dl, [esi - 1]
+        sub     ax, dx
+
+%else
+ %if TMPL_BITS == 64
+        mov     rdi, rcx                            ; rdi = pv1
+        mov     rsi, rdx                            ; rdi = pv2
+        mov     rcx, r8                             ; rcx = cbDst
+ %else
+        mov     ax, ds
+        mov     es, ax                              ; paranoia
+        mov     edi, [ebp + 4 + cbCurRetAddr]       ; pv1
+        mov     esi, [ebp + 4 + cbCurRetAddr + 4]   ; pv2
+        mov     ecx, [ebp + 4 + cbCurRetAddr + 8]   ; cbDst
+ %endif
+        xor     eax, eax
+        repe cmpsb
+        je      .return
+
+        mov     al, [xDI - 1]
+        movzx   edx, byte [xSI - 1]
+        sub     eax, edx
+%endif
+
+.return:
+TONLY16 pop     ds
+TNOT64  pop     es
+        pop     xSI
+        pop     xDI
+        pop     xBP
+        BS3_HYBRID_RET
+BS3_PROC_END_CMN   Bs3MemCmp
+