73 lines
2.0 KiB
C
73 lines
2.0 KiB
C
/* Copyright 2021 Alain Knaff.
|
|
* This file is part of mtools.
|
|
*
|
|
* Mtools 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 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* Mtools 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 Mtools. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include "sysincludes.h"
|
|
#include "llong.h"
|
|
#include "device.h"
|
|
|
|
int check_if_sectors_fit(uint32_t tot_sectors,
|
|
mt_off_t maxBytes,
|
|
uint32_t sectorSize,
|
|
char *errmsg)
|
|
{
|
|
if(!maxBytes)
|
|
return 0; /* Maxbytes = 0 => no checking */
|
|
if(tot_sectors > (smt_off_t) maxBytes / (smt_off_t) sectorSize) {
|
|
sprintf(errmsg,
|
|
"%d sectors too large for this platform\n",
|
|
tot_sectors);
|
|
return -1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Calculate number of total sectors on device if needed, and check that
|
|
* they fit into
|
|
*/
|
|
int chs_to_totsectors(struct device *dev, char *errmsg)
|
|
{
|
|
uint32_t sect_per_track, tot_sectors;
|
|
|
|
if(dev->tot_sectors)
|
|
return 0;
|
|
|
|
if(!dev->heads || !dev->sectors || !dev->tracks)
|
|
return 0; /* not fully specified => we cannot do
|
|
anything anyways */
|
|
|
|
/* Cannot overflow as both dev->heads and dev->sectors are 16
|
|
* bit quantities, whose product will be put into a 32 bit
|
|
* field */
|
|
sect_per_track = dev->heads * dev->sectors;
|
|
|
|
if(dev->tracks > UINT32_MAX / sect_per_track) {
|
|
/* Would not fit in 32 bits */
|
|
|
|
if(errmsg)
|
|
sprintf(errmsg,
|
|
"Number of sectors larger than 2^32\n");
|
|
return -1;
|
|
}
|
|
|
|
tot_sectors = dev->tracks * sect_per_track;
|
|
if(tot_sectors > dev->hidden % sect_per_track)
|
|
tot_sectors -= dev->hidden % sect_per_track;
|
|
dev->tot_sectors = tot_sectors;
|
|
return 0;
|
|
}
|