; $Id$

;; @file

; Compiler support routines.

;

;

; Copyright (C) 2012 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 __U4D

public __U4M

ifndef VBOX_PC_BIOS

public __I4D

public __I4M

endif

public _fmemset_

public _fmemcpy_

.386p

_TEXT segment public 'CODE' use16

assume cs:_TEXT

;;

; 32-bit unsigned division.

;

; @param dx:ax Dividend.

; @param cx:bx Divisor.

; @returns dx:ax Quotient.

; cx:bx Reminder.

;

__U4D:

pushf

push eax

push edx

push ecx

rol eax, 16

mov ax, dx

ror eax, 16

xor edx, edx

shr ecx, 16

mov cx, bx

div ecx ; eax:edx / ecx -> eax=quotient, edx=reminder.

mov bx, dx

pop ecx

shr edx, 16

mov cx, dx

pop edx

ror eax, 16

mov dx, ax

add sp, 2

pop ax

rol eax, 16

popf

ret

ifndef VBOX_PC_BIOS

;;

; 32-bit signed division.

;

; @param dx:ax Dividend.

; @param cx:bx Divisor.

; @returns dx:ax Quotient.

; cx:bx Reminder.

;

__I4D:

pushf

push eax

push edx

push ecx

rol eax, 16

mov ax, dx

ror eax, 16

xor edx, edx

shr ecx, 16

mov cx, bx

idiv ecx ; eax:edx / ecx -> eax=quotient, edx=reminder.

mov bx, dx

pop ecx

shr edx, 16

mov cx, dx

pop edx

ror eax, 16

mov dx, ax

add sp, 2

pop ax

rol eax, 16

popf

ret

endif ; VBOX_PC_BIOS

;;

; 32-bit unsigned multiplication.

;

; @param dx:ax Factor 1.

; @param cx:bx Factor 2.

; @returns dx:ax Result.

;

__U4M:

pushf

push eax

push edx

push ecx

rol eax, 16

mov ax, dx

ror eax, 16

xor edx, edx

shr ecx, 16

mov cx, bx

mul ecx ; eax * ecx -> edx:eax

pop ecx

pop edx

ror eax, 16

mov dx, ax

add sp, 2

pop ax

rol eax, 16

popf

ret

ifndef VBOX_PC_BIOS

;;

; 32-bit unsigned multiplication.

; memset taking a far pointer.

;

; @param dx:ax Factor 1.

; @param cx:bx Factor 2.

; @returns dx:ax Result.

; cx, es may be modified; di is preserved

;

__I4M:

pushf

push eax

push edx

push ecx

push ebx

rol eax, 16

mov ax, dx

ror eax, 16

xor edx, edx

shr ecx, 16

mov cx, bx

imul ecx ; eax * ecx -> edx:eax

pop ebx

pop ecx

pop edx

ror eax, 16

mov dx, ax

add sp, 2

pop ax

rol eax, 16

popf

ret

endif ; VBOX_PC_BIOS

;;

; memset taking a far pointer.

;

; cx, es may be modified; di is preserved

;

; @returns dx:ax unchanged.

; @param dx:ax Pointer to the memory.

; @param bl The fill value.

; @param cx The number of bytes to fill.

;

_fmemset_:

push di

mov es, dx

mov di, ax

xchg al, bl

rep stosb

xchg al, bl

pop di

ret

;;

; memset taking far pointers.

;

; cx, es may be modified; si, di are preserved

;

; @returns dx:ax unchanged.

; @param dx:ax Pointer to the destination memory.

; @param cx:bx Pointer to the source memory.

; @param sp+2 The number of bytes to copy (dw).

;

_fmemcpy_:

push bp

mov bp, sp

push di

push ds

push si

mov es, dx

mov di, ax

mov ds, cx

mov si, bx

mov cx, [bp + 4]

rep movsb

pop si

pop ds

pop di

leave

ret

_TEXT ends

end