diff options
Diffstat (limited to 'src/VBox/Devices/BiosCommonCode/__U8RS.asm')
| -rw-r--r-- | src/VBox/Devices/BiosCommonCode/__U8RS.asm | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/src/VBox/Devices/BiosCommonCode/__U8RS.asm b/src/VBox/Devices/BiosCommonCode/__U8RS.asm new file mode 100644 index 00000000..67c02d47 --- /dev/null +++ b/src/VBox/Devices/BiosCommonCode/__U8RS.asm @@ -0,0 +1,54 @@ +; $Id: __U8RS.asm $ +;; @file +; Compiler support routines. +; + +; +; Copyright (C) 2012-2019 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. +; + + +;******************************************************************************* +;* Exported Symbols * +;******************************************************************************* +public __U8RS + + + .8086 + +_TEXT segment public 'CODE' use16 + assume cs:_TEXT + +;; +; 64-bit unsigned right shift. +; +; @param ax:bx:cx:dx Value. (AX is the most significant, DX the least) +; @param si Shift count. +; @returns ax:bx:cx:dx Shifted value. +; si is zeroed +; +__U8RS: + + test si, si + jz u8rs_quit +u8rs_rot: + shr ax, 1 + rcr bx, 1 + rcr cx, 1 + rcr dx, 1 + dec si + jnz u8rs_rot +u8rs_quit: + ret + +_TEXT ends + end + |