1 files changed, 129 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/string/strncpy.asm b/src/VBox/Runtime/common/string/strncpy.asm
new file mode 100644
index 00000000..7b39cd1e
--- /dev/null
+++ b/src/VBox/Runtime/common/string/strncpy.asm
@@ -0,0 +1,129 @@
+; $Id: strncpy.asm $
+;; @file
+; IPRT - No-CRT strncpy - AMD64 & X86.
+;
+
+;
+; Copyright (C) 2006-2020 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 "iprt/asmdefs.mac"
+
+BEGINCODE
+
+;;
+; @param    pszDst   gcc: rdi  msc: rcx  x86:[esp+4]   wcall: eax
+; @param    pszSrc   gcc: rsi  msc: rdx  x86:[esp+8]   wcall: edx
+; @param    cbMax    gcc: rdx  msc: r8   x86:[esp+12]  wcall: ebx
+RT_NOCRT_BEGINPROC strncpy
+        ; input
+%ifdef RT_ARCH_AMD64
+ %ifdef ASM_CALL64_MSC
+  %define pszDst rcx
+  %define pszSrc rdx
+  %define cbMax  r8
+ %else
+  %define pszDst rdi
+  %define pszSrc rsi
+  %define cbMax  rdx
+ %endif
+        mov     r9, pszDst
+%else
+ %ifdef ASM_CALL32_WATCOM
+  mov   ecx, eax
+  %define pszDst ecx
+  %define pszSrc edx
+  %define cbMax  ebx
+ %else
+        mov     ecx, [esp + 4]
+        mov     edx, [esp + 8]
+        push    ebx
+        mov     ebx, [esp + 12 + 4]
+  %define pszDst ecx
+  %define pszSrc edx
+  %define cbMax  ebx
+ %endif
+        push    pszDst
+%endif
+
+        ;
+        ; The rolled out loop.
+        ;
+.next:
+        cmp     cbMax, 4
+        jb      .simple_intro
+
+        mov     al, [pszSrc]
+        mov     [pszDst], al
+        test    al, al
+        jz      .done
+
+        mov     al, [pszSrc + 1]
+        mov     [pszDst + 1], al
+        test    al, al
+        jz      .done
+
+        mov     al, [pszSrc + 2]
+        mov     [pszDst + 2], al
+        test    al, al
+        jz      .done
+
+        mov     al, [pszSrc + 3]
+        mov     [pszDst + 3], al
+        test    al, al
+        jz      .done
+
+        add     pszDst, 4
+        add     pszSrc, 4
+        sub     cbMax,  4
+        jmp     .next
+
+        ;
+        ; Char by char.
+        ;
+.simple_intro:
+        test    cbMax, cbMax
+        jz      .done
+
+.simple_next:
+        mov     al, [pszSrc]
+        mov     [pszDst], al
+        test    al, al
+        jz      .done
+
+        dec     cbMax
+        jz      .done
+
+        inc     pszSrc
+        inc     pszDst
+        jmp     .simple_next
+
+.done:
+%ifdef RT_ARCH_AMD64
+        mov     rax, r9
+%else
+ %ifndef ASM_CALL32_WATCOM
+        pop     ebx
+ %endif
+        pop     eax
+%endif
+        ret
+ENDPROC RT_NOCRT(strncpy)
+