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/*
* Copyright (c) 1996, 1998 University of Utah and the Flux Group.
* All rights reserved.
*
* This file is part of the Flux OSKit. The OSKit is free software, also known
* as "open source;" you can redistribute it and/or modify it under the terms
* of the GNU General Public License (GPL), version 2, as published by the Free
* Software Foundation (FSF). To explore alternate licensing terms, contact
* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
*
* The OSKit 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 GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
/*
* Mach Operating System
* Copyright (c) 1991,1990 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
/*
* This is the layer of the partitioning code that searches for a
* specific partitioning scheme (potentially nested inside annother
* partitioning scheme).
*
* This file contains the partition code that searches for a PC BIOS label.
* It won't work on big-endian (RISC) machines, as PCs are little-endian.
*/
#include <sys/types.h>
#include <stdio.h>
#include <oskit/diskpart/diskpart.h>
#include <oskit/diskpart/pcbios.h>
/* Parts of the following code is derived from the SCSI/IDE Mach drivers */
int
diskpart_get_dos(struct diskpart *array, char *buff, int start,
void *driver_info, int (*bottom_read_fun)(),
int max_part)
{
bios_label_t *table; /* DOS partition table in the boot sector */
struct bios_partition_info *entry; /* entry in the partition table */
int count, i, j;
int ext = -1, mystart = start, mybase;
int first = 1;
/*
* Note: start is added, although a start != 0 is meaningless
* to DOS and anything else...
*/
/* check the boot sector for a partition table. Always in sector 0 */
diskpart_check_read((*bottom_read_fun)(driver_info, start, buff));
/* Check for valid partition table. */
table = (bios_label_t *)&buff[BIOS_LABEL_BYTE_OFFSET];
if (table->magic != BIOS_LABEL_MAGIC) {
return(0); /* didn't add any partitions */
}
count = min(4,max_part); /* always 4 (primary) partitions */
j = 0;
for (i = 0, entry = (struct bios_partition_info *)table->partitions;
i < 4 ; entry++,i++)
if (entry->n_sectors != 0) j++; /* count non-empty partition */
if (j == 0) return(0); /* all are empty -- didn't find it */
/* fill the next 4 entries in the array */
for (i = 0, entry = (struct bios_partition_info *)table->partitions;
i < count; i++, entry++) {
diskpart_fill_entry(&array[i], entry->offset, entry->n_sectors,
NULL, 0, DISKPART_NONE, entry->systid);
if ((entry->systid == DOS_EXTENDED) && (ext < 0)) {
mystart += entry->offset;
ext = i;
}
}
/*
* If there is an extended partition, find all the logical partitions
* note: logical start at '5' (extended is one of the numbered 1-4)
*/
/*
* Logical partitions 'should' be nested inside the primary, but
* then it would be impossible to NAME a disklabel inside a logical
* partition, which would be nice to do
*/
while (ext >= 0) {
entry = &(((struct bios_partition_info *)
table->partitions)[ext]);
/* read the EXTENDED partition table */
if (first) {
mybase = mystart;
first = 0;
} else {
mybase = mystart + entry->offset;
}
diskpart_check_read((*bottom_read_fun)(driver_info,
mybase, buff));
if (table->magic != BIOS_LABEL_MAGIC) {
return(count); /*don't add any more partitions*/
}
/* just in case more than one partition is there...*/
/* search the EXTENDED partition table */
for (j = 0, ext = -1,
entry = (struct bios_partition_info *)
table->partitions;
j < 4; j++, entry++) {
if (entry->systid && (entry->systid!=DOS_EXTENDED)) {
if (count < max_part) {
diskpart_fill_entry(&array[count],
mybase + entry->offset,
entry->n_sectors, NULL, 0, DISKPART_NONE,
entry->systid);
count++; }
else {
return(count);
}
} else if ((ext < 0) &&
(entry->systid == DOS_EXTENDED)) {
ext = j;
/* recursivly search the chain here */
}
}
}
return(count); /* number dos partitions found */
}
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