; $Id: bs3-mode-DiskQueryGeometry.asm 102150 2023-11-20 11:14:18Z vboxsync $ ;; @file ; BS3Kit - Bs3BiosInt15hE820 ; ; ; Copyright (C) 2021-2023 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" ;********************************************************************************************************************************* ;* Defined Constants And Macros * ;********************************************************************************************************************************* ;; Signature: 'SMAP' %define INT15_E820_SIGNATURE 0534d4150h ;********************************************************************************************************************************* ;* 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 ;; ; Performs a int 13h function 8 call. ; ; @cproto BS3_MODE_PROTO_STUB(uint8_t, Bs3DiskQueryGeometry,(uint8_t bDrive, uint16_t *puMaxCylinder, ; uint8_t *puMaxHead, uint8_t *puMaxSector)); ; ; @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 Bs3DiskQueryGeometry, 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_puMaxCylinder [xBP + xCB + cbCurRetAddr + xCB + sCB*0] %define a_pMaxHead [xBP + xCB + cbCurRetAddr + xCB + sCB*1] %define a_puMaxSector [xBP + xCB + cbCurRetAddr + xCB + sCB*2] %ifdef TMPL_64BIT mov a_bDrive, rcx ; save bDrive mov a_puMaxCylinder, rdx ; save pcCylinders mov a_pMaxHead, r8 ; save pcHeads mov a_puMaxSector, r9 ; save pcSectors movzx edx, cl ; dl = drive %else mov dl, a_bDrive ; dl = drive %endif ; ; 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 ; Ralf Brown suggest setting es:di to NULL before the call. This is also helpful ; wrt to IVT manipulation (next step). xor di, di mov es, di ; ; Save current and restore the original IVT[13h] entry. ; mov si, seg g_aBs3RmIvtOriginal mov ds, si mov si, g_aBs3RmIvtOriginal push word [es:13h * 4] mov ax, [si + 13h * 4] mov [es:13h * 4], ax push word [es:13h * 4 + 2] mov ax, [si + 13h * 4 + 2] mov [es:13h * 4 + 2], ax ; ; Make the call. ; mov ax, 0800h ; ah=08h xor di, di ; ralf brown suggestion to guard against bios bugs. mov es, di int 13h ; ; Restore the modified IVT[13h] entry. ; Must not touch EFLAGS.CF! ; push word 0 pop ds pop word [ds:13h * 4 + 2] pop word [ds:13h * 4] ; ; 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 ; ; Check that we didn't failed. ; jc .failed_return_ah ; ; Save the return values. ; CL[7:6]:CH = max cylinders. ; DH = max heads ; CL[5:0] = max sectors ; Other stuff we don't care about: ; AH = 0 ; AL = undefined/zero ; BL = drive type ; DL = max drives. ; ES:DI = driver parameter table for floppies. ; %ifdef TMPL_16BIT les di, a_pMaxHead mov [es:di], dh les di, a_puMaxSector mov al, 3fh and al, cl mov [es:di], al les di, a_puMaxCylinder shr cl, 6 xchg cl, ch mov [es:di], cx %else mov xDI, a_pMaxHead mov [xDI], dh mov xDI, a_puMaxSector mov al, 3fh and al, cl mov [xDI], al mov xDI, a_puMaxCylinder shr cl, 6 xchg cl, ch mov [xDI], cx %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 Bs3DiskQueryGeometry