1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
/* 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;
}
|
