minix/commands/i386/mtools-3.9.7/init.c
2005-04-21 14:53:53 +00:00

414 lines
8.8 KiB
C
Executable file

/*
* Initialize an MSDOS diskette. Read the boot sector, and switch to the
* proper floppy disk device to match the format on the disk. Sets a bunch
* of global variables. Returns 0 on success, or 1 on failure.
*/
#include "sysincludes.h"
#include "msdos.h"
#include "stream.h"
#include "mtools.h"
#include "fsP.h"
#include "plain_io.h"
#include "floppyd_io.h"
#include "xdf_io.h"
#include "buffer.h"
extern int errno;
#ifndef OS_Minix /* Minix is memory starved. */
#define FULL_CYL
#endif
unsigned int num_clus; /* total number of cluster */
/*
* Read the boot sector. We glean the disk parameters from this sector.
*/
static int read_boot(Stream_t *Stream, struct bootsector * boot, int size)
{
/* read the first sector, or part of it */
if(!size)
size = BOOTSIZE;
if(size > 1024)
size = 1024;
if (force_read(Stream, (char *) boot, 0, size) != size)
return -1;
return 0;
}
static int fs_flush(Stream_t *Stream)
{
DeclareThis(Fs_t);
fat_write(This);
return 0;
}
Class_t FsClass = {
read_pass_through, /* read */
write_pass_through, /* write */
fs_flush,
fs_free, /* free */
0, /* set geometry */
get_data_pass_through,
0 /* pre allocate */
};
static int get_media_type(Stream_t *St, struct bootsector *boot)
{
int media;
media = boot->descr;
if(media < 0xf0){
char temp[512];
/* old DOS disk. Media descriptor in the first FAT byte */
/* old DOS disk always have 512-byte sectors */
if (force_read(St,temp,(mt_off_t) 512,512) == 512)
media = (unsigned char) temp[0];
else
media = 0;
} else
media += 0x100;
return media;
}
Stream_t *GetFs(Stream_t *Fs)
{
while(Fs && Fs->Class != &FsClass)
Fs = Fs->Next;
return Fs;
}
Stream_t *find_device(char *drive, int mode, struct device *out_dev,
struct bootsector *boot,
char *name, int *media, mt_size_t *maxSize)
{
char errmsg[200];
Stream_t *Stream;
struct device *dev;
int r;
#ifdef OS_Minix
static char *devname;
struct device onedevice[2];
struct stat stbuf;
free(devname);
devname = safe_malloc((9 + strlen(drive)) * sizeof(devname[0]));
strcpy(devname, "/dev/dosX");
if (isupper(drive[0]) && drive[1] == 0) {
/* single letter device name, use /dev/dos$drive */
devname[8]= drive[0];
} else
if (strchr(drive, '/') == NULL) {
/* a simple name, use /dev/$drive */
strcpy(devname+5, drive);
} else {
/* a pathname, use as is. */
strcpy(devname, drive);
}
if (stat(devname, &stbuf) != -1) {
memset(onedevice, 0, sizeof(onedevice));
onedevice[0].name = devname;
onedevice[0].drive = drive;
onedevice[1].name = NULL;
onedevice[1].drive = NULL;
dev = onedevice;
} else {
dev = devices;
}
#else
dev = devices;
#endif
Stream = NULL;
sprintf(errmsg, "Drive '%s:' not supported", drive);
/* open the device */
for (; dev->name; dev++) {
FREE(&Stream);
if (strcmp(dev->drive, drive) != 0)
continue;
*out_dev = *dev;
expand(dev->name,name);
#ifdef USING_NEW_VOLD
strcpy(name, getVoldName(dev, name));
#endif
Stream = 0;
#ifdef USE_XDF
Stream = XdfOpen(out_dev, name, mode, errmsg, 0);
if(Stream) {
out_dev->use_2m = 0x7f;
if(maxSize)
*maxSize = max_off_t_31;
}
#endif
#ifdef USE_FLOPPYD
if(!Stream) {
Stream = FloppydOpen(out_dev, dev, name, mode, errmsg, 0, 1);
if(Stream && maxSize)
*maxSize = max_off_t_31;
}
#endif
if (!Stream)
Stream = SimpleFileOpen(out_dev, dev, name, mode,
errmsg, 0, 1, maxSize);
if( !Stream)
continue;
/* read the boot sector */
if ((r=read_boot(Stream, boot, out_dev->blocksize)) < 0){
sprintf(errmsg,
"init %s: could not read boot sector",
drive);
continue;
}
if((*media= get_media_type(Stream, boot)) <= 0xf0 ){
if (boot->jump[2]=='L')
sprintf(errmsg,
"diskette %s: is Linux LILO, not DOS",
drive);
else
sprintf(errmsg,"init %s: non DOS media", drive);
continue;
}
/* set new parameters, if needed */
errno = 0;
if(SET_GEOM(Stream, out_dev, dev, *media, boot)){
if(errno)
#ifdef HAVE_SNPRINTF
snprintf(errmsg, 199,
"Can't set disk parameters for %s: %s",
drive, strerror(errno));
#else
sprintf(errmsg,
"Can't set disk parameters for %s: %s",
drive, strerror(errno));
#endif
else
sprintf(errmsg,
"Can't set disk parameters for %s",
drive);
continue;
}
break;
}
/* print error msg if needed */
if ( dev->drive == 0 ){
FREE(&Stream);
fprintf(stderr,"%s\n",errmsg);
return NULL;
}
#ifdef OS_Minix
/* Minix can lseek up to 4G. */
if (maxSize) *maxSize = 0xFFFFFFFFUL;
#endif
return Stream;
}
Stream_t *fs_init(char *drive, int mode)
{
int blocksize;
int media,i;
int nhs;
int disk_size = 0; /* In case we don't happen to set this below */
size_t tot_sectors;
char name[EXPAND_BUF];
int cylinder_size;
struct device dev;
mt_size_t maxSize;
struct bootsector boot0;
#define boot (&boot0)
Fs_t *This;
This = New(Fs_t);
if (!This)
return NULL;
This->Direct = NULL;
This->Next = NULL;
This->refs = 1;
This->Buffer = 0;
This->Class = &FsClass;
This->preallocatedClusters = 0;
This->lastFatSectorNr = 0;
This->lastFatAccessMode = 0;
This->lastFatSectorData = 0;
This->drive = drive;
This->last = 0;
This->Direct = find_device(drive, mode, &dev, &boot0, name, &media,
&maxSize);
if(!This->Direct)
return NULL;
This->sector_size = WORD(secsiz);
if(This->sector_size > MAX_SECTOR){
fprintf(stderr,"init %s: sector size too big\n", drive);
return NULL;
}
i = log_2(This->sector_size);
if(i == 24) {
fprintf(stderr,
"init %c: sector size (%d) not a small power of two\n",
drive, This->sector_size);
return NULL;
}
This->sectorShift = i;
This->sectorMask = This->sector_size - 1;
cylinder_size = dev.heads * dev.sectors;
if (!tot_sectors) tot_sectors = dev.tracks * cylinder_size;
This->serialized = 0;
if ((media & ~7) == 0xf8){
i = media & 3;
This->cluster_size = old_dos[i].cluster_size;
tot_sectors = cylinder_size * old_dos[i].tracks;
This->fat_start = 1;
This->fat_len = old_dos[i].fat_len;
This->dir_len = old_dos[i].dir_len;
This->num_fat = 2;
This->sector_size = 512;
This->sectorShift = 9;
This->sectorMask = 511;
This->fat_bits = 12;
nhs = 0;
} else {
struct label_blk_t *labelBlock;
/*
* all numbers are in sectors, except num_clus
* (which is in clusters)
*/
tot_sectors = WORD(psect);
if(!tot_sectors) {
tot_sectors = DWORD(bigsect);
nhs = DWORD(nhs);
} else
nhs = WORD(nhs);
This->cluster_size = boot0.clsiz;
This->fat_start = WORD(nrsvsect);
This->fat_len = WORD(fatlen);
This->dir_len = WORD(dirents) * MDIR_SIZE / This->sector_size;
This->num_fat = boot0.nfat;
if (This->fat_len) {
labelBlock = &boot0.ext.old.labelBlock;
} else {
labelBlock = &boot0.ext.fat32.labelBlock;
}
if(labelBlock->dos4 == 0x29) {
This->serialized = 1;
This->serial_number = _DWORD(labelBlock->serial);
}
}
if (tot_sectors >= (maxSize >> This->sectorShift)) {
fprintf(stderr, "Big disks not supported on this architecture\n");
exit(1);
}
#ifndef OS_Minix /* Strange check, MS-DOS isn't that picky. */
if(!mtools_skip_check && (tot_sectors % dev.sectors)){
fprintf(stderr,
"Total number of sectors not a multiple of"
" sectors per track!\n");
fprintf(stderr,
"Add mtools_skip_check=1 to your .mtoolsrc file "
"to skip this test\n");
exit(1);
}
#endif
/* full cylinder buffering */
#ifdef FULL_CYL
disk_size = (dev.tracks) ? cylinder_size : 512;
#else /* FULL_CYL */
disk_size = (dev.tracks) ? dev.sectors : 512;
#endif /* FULL_CYL */
#if (defined OS_sysv4 && !defined OS_solaris)
/*
* The driver in Dell's SVR4 v2.01 is unreliable with large writes.
*/
disk_size = 0;
#endif /* (defined sysv4 && !defined(solaris)) */
#ifdef OS_linux
disk_size = cylinder_size;
#endif
#if 1
if(disk_size > 256) {
disk_size = dev.sectors;
if(dev.sectors % 2)
disk_size <<= 1;
}
#endif
if (disk_size % 2)
disk_size *= 2;
if(!dev.blocksize || dev.blocksize < This->sector_size)
blocksize = This->sector_size;
else
blocksize = dev.blocksize;
if (disk_size)
This->Next = buf_init(This->Direct,
8 * disk_size * blocksize,
disk_size * blocksize,
This->sector_size);
else
This->Next = This->Direct;
if (This->Next == NULL) {
perror("init: allocate buffer");
This->Next = This->Direct;
}
/* read the FAT sectors */
if(fat_read(This, &boot0, dev.fat_bits, tot_sectors, dev.use_2m&0x7f)){
This->num_fat = 1;
FREE(&This->Next);
Free(This->Next);
return NULL;
}
return (Stream_t *) This;
}
char *getDrive(Stream_t *Stream)
{
DeclareThis(Fs_t);
if(This->Class != &FsClass)
return getDrive(GetFs(Stream));
else
return This->drive;
}
int fsPreallocateClusters(Fs_t *Fs, long size)
{
if(size > 0 && getfreeMinClusters((Stream_t *)Fs, size) != 1)
return -1;
Fs->preallocatedClusters += size;
return 0;
}