; $Id: bs3-mode-DiskRead.asm 106061 2024-09-16 14:03:52Z vboxsync $ ;; @file ; BS3Kit - Bs3DiskRead ; ; ; Copyright (C) 2021-2024 Oracle and/or its affiliates. ; ; This file is part of VirtualBox base platform packages, as ; available from https://www.virtualbox.org. ; ; This program is free software; you can redistribute it and/or ; modify it under the terms of the GNU General Public License ; as published by the Free Software Foundation, in version 3 of the ; License. ; ; This program is distributed in the hope that it will be useful, but ; WITHOUT ANY WARRANTY; without even the implied warranty of ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU ; General Public License for more details. ; ; You should have received a copy of the GNU General Public License ; along with this program; if not, see . ; ; The contents of this file may alternatively be used under the terms ; of the Common Development and Distribution License Version 1.0 ; (CDDL), a copy of it is provided in the "COPYING.CDDL" file included ; in the VirtualBox 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. ; ; SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 ; ;********************************************************************************************************************************* ;* Header Files * ;********************************************************************************************************************************* %include "bs3kit-template-header.mac" ;********************************************************************************************************************************* ;* External symbols * ;********************************************************************************************************************************* TMPL_BEGIN_TEXT extern TMPL_NM(Bs3SwitchToRM) BS3_BEGIN_TEXT16 extern RT_CONCAT3(_Bs3SwitchTo,TMPL_MODE_UNAME,_Safe_rm) BS3_EXTERN_DATA16 g_aBs3RmIvtOriginal %ifdef TMPL_16BIT BS3_EXTERN_CMN Bs3SelProtFar16DataToRealMode %else BS3_EXTERN_CMN Bs3SelFlatDataToRealMode %endif ;; ; Performs a int 13h function 2 call. ; ; @cproto BS3_MODE_PROTO_STUB(uint8_t, Bs3DiskRead,(uint8_t bDrive, uint16_t uCylinder, uint8_t uHead, uint8_t uSector, ; uint8_t cSectors, void RT_FAR *pvBuf)); ; ; @returns Register value (ax/eax). Zero on success, non-zero on failure. ; ; @uses No GPRs (only return full register(s)). In 64-bit mode DS and ES is trashed. ; ; @remarks ASSUMES we're in ring-0 when not in some kind of real mode. ; @remarks ASSUMES we're on a 16-bit suitable stack. ; TMPL_BEGIN_TEXT BS3_PROC_BEGIN_MODE Bs3DiskRead, BS3_PBC_HYBRID push xBP mov xBP, xSP ;; @todo does not work on 286 and earlier! sPUSHF cli push sBX push sCX push sDX push sSI push sDI %ifndef TMPL_64BIT push ds push es %endif ; Load/Save parameters. %define a_bDrive [xBP + xCB + cbCurRetAddr + xCB*0] %define a_uCylinder [xBP + xCB + cbCurRetAddr + xCB*1] %define a_uCylinderHi [xBP + xCB + cbCurRetAddr + xCB*1 + 1] %define a_uHead [xBP + xCB + cbCurRetAddr + xCB*2] %define a_uSector [xBP + xCB + cbCurRetAddr + xCB*3] %define a_cSectors [xBP + xCB + cbCurRetAddr + xCB*4] %define a_pvBuf [xBP + xCB + cbCurRetAddr + xCB*5] %define a_pvBufSel [xBP + xCB + cbCurRetAddr + xCB*5 + 2] %ifdef TMPL_64BIT mov a_bDrive, rcx ; save bDrive mov a_uCylinder, rdx ; save uCylinder mov a_uHead, r8 ; save uHead mov a_uSector, r9 ; save uSector movzx edx, cl ; dl = drive %else mov dl, a_bDrive ; dl = drive %endif ; ; Convert buffer pointer if not in real mode. ; Note! We clean the stack up in the epilogue. ; %ifdef TMPL_64BIT sub rsp, 20h mov rcx, a_pvBuf call Bs3SelFlatDataToRealMode mov a_pvBuf, rax %elifdef TMPL_32BIT mov ecx, a_pvBuf push ecx call Bs3SelFlatDataToRealMode mov a_pvBuf, eax %elif !BS3_MODE_IS_RM_OR_V86(TMPL_MODE) push word a_pvBufSel push word a_pvBuf call Bs3SelProtFar16DataToRealMode mov a_pvBuf, ax mov a_pvBufSel, dx %endif ; ; Set up the BIOS call parameters. ; mov ah, 02h ; read mov al, a_cSectors mov dh, a_uHead mov dl, a_bDrive ; For 63.5MB support the entire CL is the sector number, so just treat floppies special. cmp dl, 4 ; ASSUMES the first 4 drive are potentially BIG floppies. jb .floppy mov cx, a_uCylinder xchg ch, cl shl cl, 6 or cl, a_uSector jmp .setup_addr .floppy: mov ch, a_uCylinder mov cl, a_uSector .setup_addr: mov bx, a_pvBuf mov di, a_pvBufSel ; ; Switch to real mode, first we just to the 16-bit text segment. ; This preserve all 32-bit register values. ; %if TMPL_MODE != BS3_MODE_RM %ifndef TMPL_16BIT jmp .to_text16 BS3_BEGIN_TEXT16 .to_text16: BS3_SET_BITS TMPL_BITS %endif call TMPL_NM(Bs3SwitchToRM) BS3_SET_BITS 16 %endif ; ; Make the call. ; mov es, di ; pushf ; sti int 13h ; popf ; ; Switch back. ; %if TMPL_MODE != BS3_MODE_RM call RT_CONCAT3(_Bs3SwitchTo,TMPL_MODE_UNAME,_Safe_rm) BS3_SET_BITS TMPL_BITS %ifndef TMPL_16BIT jmp .from_text16 TMPL_BEGIN_TEXT .from_text16: %endif %endif hlt ; ; Check that we didn't failed. ; jc .failed_return_ah test ah, ah jnz .failed_return_ah %ifdef BS3_STRICT cmp al, a_cSectors je .next int3 .next: %endif ; ; Return success ; mov al, 0 .return: %ifndef TMPL_64BIT lea xSP, [xBP - sCB * 6 - xCB*2] pop es pop ds %else lea xSP, [xBP - sCB * 6] %endif pop sDI pop sSI pop sDX pop sCX pop sBX sPOPF leave BS3_HYBRID_RET ; ; Failed. ; .failed_return_ah: mov al, ah cmp al, 0 jne .return dec al jmp .return BS3_PROC_END_MODE Bs3DiskRead