; $Id$

;; @file

; MMRamGCA - Guest Context Ram access Assembly Routines.

;

;

; Copyright (C) 2006-2007 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.

;

;*******************************************************************************

;* Header Files *

;*******************************************************************************

%include "VBox/asmdefs.mac"

%include "VBox/err.mac"

%include "iprt/err.mac"

%include "VBox/x86.mac"

BEGINCODE

;;

; Read data in guest context, CDECL calling conv.

; VMMRCDECL(int) MMGCRamRead(void *pDst, void *pSrc, size_t cb);

; MMRamGC page fault handler must be installed prior this call for safe operation.

;

; @returns eax=0 if data read, other code - invalid access, #PF was generated.

; @param [esp + 04h] Param 1 - Pointer where to store result data (pDst).

; @param [esp + 08h] Param 2 - Pointer of data to read (pSrc).

; @param [esp + 0ch] Param 3 - Size of data to read, only 1/2/4/8 is valid.

; @uses eax, ecx, edx

;

; @remark Data is saved to destination (Param 1) even if read error occurred!

;

align 16

BEGINPROC MMGCRamReadNoTrapHandler

mov eax, [esp + 0ch] ; eax = size of data to read

cmp eax, byte 8 ; yes, it's slow, validate input

ja ramread_InvalidSize

mov edx, [esp + 04h] ; edx = result address

mov ecx, [esp + 08h] ; ecx = data address

jmp [ramread_table + eax*4]

ramread_byte:

xor eax, eax ; rc = VINF_SUCCESS by default

mov cl, [ecx] ; read data

mov [edx], cl ; save data

ret

ramread_word:

xor eax, eax ; rc = VINF_SUCCESS by default

mov cx, [ecx] ; read data

mov [edx], cx ; save data

ret

ramread_dword:

xor eax, eax ; rc = VINF_SUCCESS by default

mov ecx, [ecx] ; read data

mov [edx], ecx ; save data

ret

ramread_qword:

mov eax, [ecx] ; read data

mov [edx], eax ; save data

mov eax, [ecx+4] ; read data

mov [edx+4], eax ; save data

xor eax, eax ; rc = VINF_SUCCESS by default

ret

; Read error - we will be here after our page fault handler.

GLOBALNAME MMGCRamRead_Error

mov eax, VERR_ACCESS_DENIED

ret

; Invalid data size

ramread_InvalidSize:

mov eax, VERR_INVALID_PARAMETER

ret

; Jump table

ramread_table:

DD ramread_InvalidSize

DD ramread_byte

DD ramread_word

DD ramread_InvalidSize

DD ramread_dword

DD ramread_InvalidSize

DD ramread_InvalidSize

DD ramread_InvalidSize

DD ramread_qword

ENDPROC MMGCRamReadNoTrapHandler

;;

; Write data in guest context, CDECL calling conv.

; VMMRCDECL(int) MMGCRamWrite(void *pDst, void *pSrc, size_t cb);

;

; @returns eax=0 if data written, other code - invalid access, #PF was generated.

; @param [esp + 04h] Param 1 - Pointer where to write data (pDst).

; @param [esp + 08h] Param 2 - Pointer of data to write (pSrc).

; @param [esp + 0ch] Param 3 - Size of data to write, only 1/2/4 is valid.

; @uses eax, ecx, edx

;

align 16

BEGINPROC MMGCRamWriteNoTrapHandler

mov eax, [esp + 0ch] ; eax = size of data to write

cmp eax, byte 4 ; yes, it's slow, validate input

ja ramwrite_InvalidSize

mov edx, [esp + 04h] ; edx = write address

mov ecx, [esp + 08h] ; ecx = data address

jmp [ramwrite_table + eax*4]

ramwrite_byte:

xor eax, eax ; rc = VINF_SUCCESS by default

mov cl, [ecx] ; read data

mov [edx], cl ; write data

ret

ramwrite_word:

xor eax, eax ; rc = VINF_SUCCESS by default

mov cx, [ecx] ; read data

mov [edx], cx ; write data

ret

ramwrite_dword:

xor eax, eax ; rc = VINF_SUCCESS by default

mov ecx, [ecx] ; read data

mov [edx], ecx ; write data

ret

; Write error - we will be here after our page fault handler.

GLOBALNAME MMGCRamWrite_Error

mov eax, VERR_ACCESS_DENIED

ret

; Invalid data size

ramwrite_InvalidSize:

mov eax, VERR_INVALID_PARAMETER

ret

; Jump table

ramwrite_table:

DD ramwrite_InvalidSize

DD ramwrite_byte

DD ramwrite_word

DD ramwrite_InvalidSize

DD ramwrite_dword

ENDPROC MMGCRamWriteNoTrapHandler