/*

	FIPS - the First nondestructive Interactive Partition Splitting program



	Module disk_io.cpp



	RCS - Header:

	$Header: c:/daten/fips/source/main/RCS/disk_io.cpp 1.4 1995/01/19 00:00:51 schaefer Exp schaefer $



	Copyright (C) 1993 Arno Schaefer



	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; either version 2 of the License, or

	(at your option) any later version.



	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, write to the Free Software

	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.





	Report problems and direct all questions to:



	schaefer@rbg.informatik.th-darmstadt.de

*/



#include "disk_io.h"

#include <dos.h>

#include <bios.h>



#define DISK_INT 0x13



#define RESET_DISK 0

#define READ_SECTOR 2

#define WRITE_SECTOR 3

#define VERIFY_SECTOR 4

#define GET_DRIVE_PARAMS 8

#define GET_DISK_TYPE 0x15





/* ----------------------------------------------------------------------- */

/* Bios call to get the number of drives attached                          */

/* ----------------------------------------------------------------------- */



int get_no_of_drives (void)

{

	union REGS regs;



	regs.h.ah = GET_DRIVE_PARAMS;

	regs.h.dl = 0x80;

	int86 (DISK_INT, &regs, &regs);



	if (regs.h.ah != 0) return (1); // will be checked again

	return (regs.h.dl);

}





/* ----------------------------------------------------------------------- */

/* Calculates physical sector number (Head, Cylinder, Sector).             */

/* Log_sector is absolute logical sector number (0 = master boot record).  */

/* ----------------------------------------------------------------------- */



physical_sector_no::physical_sector_no

(

	dword logical_sector,

	const drive_geometry &geometry

)

{

	cylinder =

		logical_sector

		/ (geometry.heads * geometry.sectors);



	head =

	(

		logical_sector

		- (cylinder * geometry.heads * geometry.sectors)

	)

	/ geometry.sectors;



	sector =

		logical_sector

		- (cylinder * geometry.heads * geometry.sectors)

		- (head * geometry.sectors)

		+ 1;

}





/* ----------------------------------------------------------------------- */

/* Bios call get_drive_geometry, returns error status in var errorcode     */

/* ----------------------------------------------------------------------- */



void physical_drive::get_geometry (void)

{

	union REGS regs;



	regs.h.ah = GET_DRIVE_PARAMS;

	regs.h.dl = number;

	int86 (DISK_INT, &regs, &regs);



	if ((errorcode = regs.h.ah) != 0) return;



	geometry.heads = (dword) regs.h.dh + 1;

	geometry.sectors = (dword) regs.h.cl & 0x3f;

	geometry.cylinders =

	(

		(dword) regs.h.ch

		| (((dword) regs.h.cl << 2) & 0x300)

	) + 1;

}





/* ----------------------------------------------------------------------- */

/* Bios call reset_drive, returns error status in var errorcode            */

/* ----------------------------------------------------------------------- */



void physical_drive::reset (void)

{

	union REGS regs;



	regs.h.ah = RESET_DISK;

	regs.h.dl = number;

	int86 (DISK_INT, &regs, &regs);



	errorcode = regs.h.ah;

}





/* ----------------------------------------------------------------------- */

/* Initialization physical_drive, requires drive number.                   */

/* Calls get_drive_geometry, errorcode contains return status              */

/* ----------------------------------------------------------------------- */



physical_drive::physical_drive (int number)

{

	physical_drive::number = number;

	get_geometry ();

};





/* ----------------------------------------------------------------------- */

/* Initialization physical_drive with physical_drive object                */

/* ----------------------------------------------------------------------- */



physical_drive::physical_drive (physical_drive &pd)

{

	number = pd.number;

	errorcode = pd.errorcode;

	geometry = pd.geometry;

}





/* ----------------------------------------------------------------------- */

/* Assignment operator for physical drive                                  */

/* ----------------------------------------------------------------------- */



void physical_drive::operator= (physical_drive &pd)

{

	number = pd.number;

	errorcode = pd.errorcode;

	geometry = pd.geometry;

}





/* ----------------------------------------------------------------------- */

/* Read sector                                                             */

/* ----------------------------------------------------------------------- */



int physical_drive::read_sector (struct sector *sector, dword sector_number)

{

	physical_sector_no p (sector_number, geometry);



	boolean done = false;



	for (int i=0; i<3; i++)

	{

		if (biosdisk

		(

			READ_SECTOR,

			number,

			p.head,

			p.cylinder,

			p.sector,

			1,

			sector->data

		) == 0)

		{

			done=true;

			break;

		}



		reset ();

	}



	if (!done) return (-1);

	return 0;

}





/* ----------------------------------------------------------------------- */

/* Write sector with verify                                                */

/* ----------------------------------------------------------------------- */



int physical_drive::write_sector (struct sector *sector, dword sector_number)

{

	physical_sector_no p (sector_number,geometry);



	boolean done = false;



	for (int i=0; i<3; i++)

	{

		if (biosdisk

		(

			WRITE_SECTOR,

			number,

			p.head,

			p.cylinder,

			p.sector,

			1,

			sector->data

		) == 0)

		{

			done=true;

			break;

		}



		reset ();

	}



	if (!done) return (-1);



	if (biosdisk

	(

		VERIFY_SECTOR,

		number,

		p.head,

		p.cylinder,

		p.sector,

		1,

		sector->data



	) != 0) return (-1);



	return 0;

}





/* ----------------------------------------------------------------------- */

/* Bios call get_disk_type - returns 0 if drive not present.               */

/* Valid drive numbers: 0 - 255, result: 1 - floppy without disk change    */

/* detection, 2 - floppy with disk change detection, 3 - harddisk          */

/* ----------------------------------------------------------------------- */



int get_disk_type (int drive_number)

{

	union REGS regs;



	regs.h.ah = GET_DISK_TYPE;

	regs.h.dl = drive_number;

	int86 (DISK_INT, &regs, &regs);



	if (regs.x.cflag) return 0;

	return (regs.h.ah);                     // disk type

}