17dd7cddfSDavid du Colombier #include <u.h>
27dd7cddfSDavid du Colombier #include <libc.h>
37dd7cddfSDavid du Colombier #include <bio.h>
47dd7cddfSDavid du Colombier #include <ctype.h>
57dd7cddfSDavid du Colombier #include <disk.h>
67dd7cddfSDavid du Colombier
77dd7cddfSDavid du Colombier static Disk*
mkwidth(Disk * disk)87dd7cddfSDavid du Colombier mkwidth(Disk *disk)
97dd7cddfSDavid du Colombier {
107dd7cddfSDavid du Colombier char buf[40];
117dd7cddfSDavid du Colombier
12*8673b4daSDavid du Colombier snprint(buf, sizeof buf, "%lld", disk->size);
137dd7cddfSDavid du Colombier disk->width = strlen(buf);
147dd7cddfSDavid du Colombier return disk;
157dd7cddfSDavid du Colombier }
167dd7cddfSDavid du Colombier
177dd7cddfSDavid du Colombier /*
187dd7cddfSDavid du Colombier * Discover the disk geometry by various sleazeful means.
197dd7cddfSDavid du Colombier *
207dd7cddfSDavid du Colombier * First, if there is a partition table in sector 0,
217dd7cddfSDavid du Colombier * see if all the partitions have the same end head
227dd7cddfSDavid du Colombier * and sector; if so, we'll assume that that's the
237dd7cddfSDavid du Colombier * right count.
247dd7cddfSDavid du Colombier *
257dd7cddfSDavid du Colombier * If that fails, we'll try looking at the geometry that the ATA
267dd7cddfSDavid du Colombier * driver supplied, if any, and translate that as a
277dd7cddfSDavid du Colombier * BIOS might.
287dd7cddfSDavid du Colombier *
297dd7cddfSDavid du Colombier * If that too fails, which should only happen on a SCSI
307dd7cddfSDavid du Colombier * disk with no currently defined partitions, we'll try
317dd7cddfSDavid du Colombier * various common (h, s) pairs used by BIOSes when faking
327dd7cddfSDavid du Colombier * the geometries.
337dd7cddfSDavid du Colombier */
347dd7cddfSDavid du Colombier typedef struct Table Table;
357dd7cddfSDavid du Colombier typedef struct Tentry Tentry;
367dd7cddfSDavid du Colombier struct Tentry {
377dd7cddfSDavid du Colombier uchar active; /* active flag */
387dd7cddfSDavid du Colombier uchar starth; /* starting head */
397dd7cddfSDavid du Colombier uchar starts; /* starting sector */
407dd7cddfSDavid du Colombier uchar startc; /* starting cylinder */
417dd7cddfSDavid du Colombier uchar type; /* partition type */
427dd7cddfSDavid du Colombier uchar endh; /* ending head */
437dd7cddfSDavid du Colombier uchar ends; /* ending sector */
447dd7cddfSDavid du Colombier uchar endc; /* ending cylinder */
457dd7cddfSDavid du Colombier uchar xlba[4]; /* starting LBA from beginning of disc */
467dd7cddfSDavid du Colombier uchar xsize[4]; /* size in sectors */
477dd7cddfSDavid du Colombier };
487dd7cddfSDavid du Colombier enum {
497dd7cddfSDavid du Colombier Toffset = 446, /* offset of partition table in sector */
507dd7cddfSDavid du Colombier Magic0 = 0x55,
517dd7cddfSDavid du Colombier Magic1 = 0xAA,
527dd7cddfSDavid du Colombier NTentry = 4,
537dd7cddfSDavid du Colombier };
547dd7cddfSDavid du Colombier struct Table {
557dd7cddfSDavid du Colombier Tentry entry[NTentry];
567dd7cddfSDavid du Colombier uchar magic[2];
577dd7cddfSDavid du Colombier };
587dd7cddfSDavid du Colombier static int
partitiongeometry(Disk * disk)597dd7cddfSDavid du Colombier partitiongeometry(Disk *disk)
607dd7cddfSDavid du Colombier {
613ff48bf5SDavid du Colombier char *rawname;
623ff48bf5SDavid du Colombier int i, h, rawfd, s;
637dd7cddfSDavid du Colombier uchar buf[512];
647dd7cddfSDavid du Colombier Table *t;
657dd7cddfSDavid du Colombier
66f6b7ac0fSDavid du Colombier if(disk->c == 0 || disk->h == 0 || disk->s == 0)
67f6b7ac0fSDavid du Colombier return -1;
68f6b7ac0fSDavid du Colombier
697dd7cddfSDavid du Colombier t = (Table*)(buf + Toffset);
703ff48bf5SDavid du Colombier
713ff48bf5SDavid du Colombier /*
723ff48bf5SDavid du Colombier * look for an MBR first in the /dev/sdXX/data partition, otherwise
733ff48bf5SDavid du Colombier * attempt to fall back on the current partition.
743ff48bf5SDavid du Colombier */
753ff48bf5SDavid du Colombier rawname = malloc(strlen(disk->prefix) + 5); /* prefix + "data" + nul */
763ff48bf5SDavid du Colombier if(rawname == nil)
777dd7cddfSDavid du Colombier return -1;
787dd7cddfSDavid du Colombier
793ff48bf5SDavid du Colombier strcpy(rawname, disk->prefix);
803ff48bf5SDavid du Colombier strcat(rawname, "data");
813ff48bf5SDavid du Colombier rawfd = open(rawname, OREAD);
823ff48bf5SDavid du Colombier free(rawname);
833ff48bf5SDavid du Colombier if(rawfd >= 0
843ff48bf5SDavid du Colombier && seek(rawfd, 0, 0) >= 0
853ff48bf5SDavid du Colombier && readn(rawfd, buf, 512) == 512
863ff48bf5SDavid du Colombier && t->magic[0] == Magic0
873ff48bf5SDavid du Colombier && t->magic[1] == Magic1) {
883ff48bf5SDavid du Colombier close(rawfd);
893ff48bf5SDavid du Colombier } else {
903ff48bf5SDavid du Colombier if(rawfd >= 0)
913ff48bf5SDavid du Colombier close(rawfd);
923ff48bf5SDavid du Colombier if(seek(disk->fd, 0, 0) < 0
933ff48bf5SDavid du Colombier || readn(disk->fd, buf, 512) != 512
943ff48bf5SDavid du Colombier || t->magic[0] != Magic0
953ff48bf5SDavid du Colombier || t->magic[1] != Magic1) {
963ff48bf5SDavid du Colombier return -1;
973ff48bf5SDavid du Colombier }
983ff48bf5SDavid du Colombier }
993ff48bf5SDavid du Colombier
1007dd7cddfSDavid du Colombier h = s = -1;
1017dd7cddfSDavid du Colombier for(i=0; i<NTentry; i++) {
1027dd7cddfSDavid du Colombier if(t->entry[i].type == 0)
1037dd7cddfSDavid du Colombier continue;
1047dd7cddfSDavid du Colombier
1057dd7cddfSDavid du Colombier t->entry[i].ends &= 63;
1067dd7cddfSDavid du Colombier if(h == -1) {
1077dd7cddfSDavid du Colombier h = t->entry[i].endh;
1087dd7cddfSDavid du Colombier s = t->entry[i].ends;
1097dd7cddfSDavid du Colombier } else {
1107dd7cddfSDavid du Colombier /*
1117dd7cddfSDavid du Colombier * Only accept the partition info if every
1127dd7cddfSDavid du Colombier * partition is consistent.
1137dd7cddfSDavid du Colombier */
1147dd7cddfSDavid du Colombier if(h != t->entry[i].endh || s != t->entry[i].ends)
1157dd7cddfSDavid du Colombier return -1;
1167dd7cddfSDavid du Colombier }
1177dd7cddfSDavid du Colombier }
1187dd7cddfSDavid du Colombier
1197dd7cddfSDavid du Colombier if(h == -1)
1207dd7cddfSDavid du Colombier return -1;
1217dd7cddfSDavid du Colombier
1227dd7cddfSDavid du Colombier disk->h = h+1; /* heads count from 0 */
1237dd7cddfSDavid du Colombier disk->s = s; /* sectors count from 1 */
1247dd7cddfSDavid du Colombier disk->c = disk->secs / (disk->h*disk->s);
1257dd7cddfSDavid du Colombier disk->chssrc = Gpart;
1267dd7cddfSDavid du Colombier return 0;
1277dd7cddfSDavid du Colombier }
1287dd7cddfSDavid du Colombier
1297dd7cddfSDavid du Colombier /*
1307dd7cddfSDavid du Colombier * If there is ATA geometry, use it, perhaps massaged.
1317dd7cddfSDavid du Colombier */
1327dd7cddfSDavid du Colombier static int
drivergeometry(Disk * disk)1337dd7cddfSDavid du Colombier drivergeometry(Disk *disk)
1347dd7cddfSDavid du Colombier {
1357dd7cddfSDavid du Colombier int m;
1367dd7cddfSDavid du Colombier
1377dd7cddfSDavid du Colombier if(disk->c == 0 || disk->h == 0 || disk->s == 0)
1387dd7cddfSDavid du Colombier return -1;
1397dd7cddfSDavid du Colombier
1407dd7cddfSDavid du Colombier disk->chssrc = Gdisk;
1417dd7cddfSDavid du Colombier if(disk->c < 1024)
1427dd7cddfSDavid du Colombier return 0;
1437dd7cddfSDavid du Colombier
1447dd7cddfSDavid du Colombier switch(disk->h) {
1457dd7cddfSDavid du Colombier case 15:
1467dd7cddfSDavid du Colombier disk->h = 255;
1477dd7cddfSDavid du Colombier disk->c /= 17;
1487dd7cddfSDavid du Colombier return 0;
1497dd7cddfSDavid du Colombier
1507dd7cddfSDavid du Colombier default:
1517dd7cddfSDavid du Colombier for(m = 2; m*disk->h < 256; m *= 2) {
1527dd7cddfSDavid du Colombier if(disk->c/m < 1024) {
1537dd7cddfSDavid du Colombier disk->c /= m;
1547dd7cddfSDavid du Colombier disk->h *= m;
1557dd7cddfSDavid du Colombier return 0;
1567dd7cddfSDavid du Colombier }
1577dd7cddfSDavid du Colombier }
1587dd7cddfSDavid du Colombier
1597dd7cddfSDavid du Colombier /* set to 255, 63 and be done with it */
1607dd7cddfSDavid du Colombier disk->h = 255;
1617dd7cddfSDavid du Colombier disk->s = 63;
1627dd7cddfSDavid du Colombier disk->c = disk->secs / (disk->h * disk->s);
1637dd7cddfSDavid du Colombier return 0;
1647dd7cddfSDavid du Colombier }
1657dd7cddfSDavid du Colombier }
1667dd7cddfSDavid du Colombier
1677dd7cddfSDavid du Colombier /*
1687dd7cddfSDavid du Colombier * There's no ATA geometry and no partitions.
1697dd7cddfSDavid du Colombier * Our guess is as good as anyone's.
1707dd7cddfSDavid du Colombier */
1717dd7cddfSDavid du Colombier static struct {
1727dd7cddfSDavid du Colombier int h;
1737dd7cddfSDavid du Colombier int s;
1747dd7cddfSDavid du Colombier } guess[] = {
1757dd7cddfSDavid du Colombier 64, 32,
1767dd7cddfSDavid du Colombier 64, 63,
1777dd7cddfSDavid du Colombier 128, 63,
1787dd7cddfSDavid du Colombier 255, 63,
1797dd7cddfSDavid du Colombier };
1807dd7cddfSDavid du Colombier static int
guessgeometry(Disk * disk)1817dd7cddfSDavid du Colombier guessgeometry(Disk *disk)
1827dd7cddfSDavid du Colombier {
1837dd7cddfSDavid du Colombier int i;
1847dd7cddfSDavid du Colombier long c;
1857dd7cddfSDavid du Colombier
1867dd7cddfSDavid du Colombier disk->chssrc = Gguess;
1877dd7cddfSDavid du Colombier c = 1024;
1887dd7cddfSDavid du Colombier for(i=0; i<nelem(guess); i++)
1897dd7cddfSDavid du Colombier if(c*guess[i].h*guess[i].s >= disk->secs) {
1907dd7cddfSDavid du Colombier disk->h = guess[i].h;
1917dd7cddfSDavid du Colombier disk->s = guess[i].s;
1927dd7cddfSDavid du Colombier disk->c = disk->secs / (disk->h * disk->s);
1937dd7cddfSDavid du Colombier return 0;
1947dd7cddfSDavid du Colombier }
1957dd7cddfSDavid du Colombier
1967dd7cddfSDavid du Colombier /* use maximum values */
1977dd7cddfSDavid du Colombier disk->h = 255;
1987dd7cddfSDavid du Colombier disk->s = 63;
1997dd7cddfSDavid du Colombier disk->c = disk->secs / (disk->h * disk->s);
2007dd7cddfSDavid du Colombier return 0;
2017dd7cddfSDavid du Colombier }
2027dd7cddfSDavid du Colombier
2037dd7cddfSDavid du Colombier static void
findgeometry(Disk * disk)2047dd7cddfSDavid du Colombier findgeometry(Disk *disk)
2057dd7cddfSDavid du Colombier {
2067dd7cddfSDavid du Colombier if(partitiongeometry(disk) < 0
2077dd7cddfSDavid du Colombier && drivergeometry(disk) < 0
2087dd7cddfSDavid du Colombier && guessgeometry(disk) < 0) { /* can't happen */
2097dd7cddfSDavid du Colombier print("we're completely confused about your disk; sorry\n");
2107dd7cddfSDavid du Colombier assert(0);
2117dd7cddfSDavid du Colombier }
2127dd7cddfSDavid du Colombier }
2137dd7cddfSDavid du Colombier
2147dd7cddfSDavid du Colombier static Disk*
openfile(Disk * disk)2157dd7cddfSDavid du Colombier openfile(Disk *disk)
2167dd7cddfSDavid du Colombier {
2179a747e4fSDavid du Colombier Dir *d;
2187dd7cddfSDavid du Colombier
2199a747e4fSDavid du Colombier if((d = dirfstat(disk->fd)) == nil){
2207dd7cddfSDavid du Colombier free(disk);
2217dd7cddfSDavid du Colombier return nil;
2227dd7cddfSDavid du Colombier }
2237dd7cddfSDavid du Colombier
2247dd7cddfSDavid du Colombier disk->secsize = 512;
2259a747e4fSDavid du Colombier disk->size = d->length;
2267dd7cddfSDavid du Colombier disk->secs = disk->size / disk->secsize;
2277dd7cddfSDavid du Colombier disk->offset = 0;
2289a747e4fSDavid du Colombier free(d);
2297dd7cddfSDavid du Colombier
2307dd7cddfSDavid du Colombier findgeometry(disk);
2317dd7cddfSDavid du Colombier return mkwidth(disk);
2327dd7cddfSDavid du Colombier }
2337dd7cddfSDavid du Colombier
2347dd7cddfSDavid du Colombier static Disk*
opensd(Disk * disk)2357dd7cddfSDavid du Colombier opensd(Disk *disk)
2367dd7cddfSDavid du Colombier {
2377dd7cddfSDavid du Colombier Biobuf b;
2387dd7cddfSDavid du Colombier char *p, *f[10];
2397dd7cddfSDavid du Colombier int nf;
2407dd7cddfSDavid du Colombier
2417dd7cddfSDavid du Colombier Binit(&b, disk->ctlfd, OREAD);
2427dd7cddfSDavid du Colombier while(p = Brdline(&b, '\n')) {
2437dd7cddfSDavid du Colombier p[Blinelen(&b)-1] = '\0';
2447dd7cddfSDavid du Colombier nf = tokenize(p, f, nelem(f));
2457dd7cddfSDavid du Colombier if(nf >= 3 && strcmp(f[0], "geometry") == 0) {
2467dd7cddfSDavid du Colombier disk->secsize = strtoll(f[2], 0, 0);
2477dd7cddfSDavid du Colombier if(nf >= 6) {
2487dd7cddfSDavid du Colombier disk->c = strtol(f[3], 0, 0);
2497dd7cddfSDavid du Colombier disk->h = strtol(f[4], 0, 0);
2507dd7cddfSDavid du Colombier disk->s = strtol(f[5], 0, 0);
2517dd7cddfSDavid du Colombier }
2527dd7cddfSDavid du Colombier }
2537dd7cddfSDavid du Colombier if(nf >= 4 && strcmp(f[0], "part") == 0 && strcmp(f[1], disk->part) == 0) {
2547dd7cddfSDavid du Colombier disk->offset = strtoll(f[2], 0, 0);
2557dd7cddfSDavid du Colombier disk->secs = strtoll(f[3], 0, 0) - disk->offset;
2567dd7cddfSDavid du Colombier }
2577dd7cddfSDavid du Colombier }
2587dd7cddfSDavid du Colombier
2597dd7cddfSDavid du Colombier
2607dd7cddfSDavid du Colombier disk->size = disk->secs * disk->secsize;
2617dd7cddfSDavid du Colombier if(disk->size <= 0) {
2627dd7cddfSDavid du Colombier strcpy(disk->part, "");
2637dd7cddfSDavid du Colombier disk->type = Tfile;
2647dd7cddfSDavid du Colombier return openfile(disk);
2657dd7cddfSDavid du Colombier }
2667dd7cddfSDavid du Colombier
2677dd7cddfSDavid du Colombier findgeometry(disk);
2687dd7cddfSDavid du Colombier return mkwidth(disk);
2697dd7cddfSDavid du Colombier }
2707dd7cddfSDavid du Colombier
2717dd7cddfSDavid du Colombier Disk*
opendisk(char * disk,int rdonly,int noctl)2727dd7cddfSDavid du Colombier opendisk(char *disk, int rdonly, int noctl)
2737dd7cddfSDavid du Colombier {
2747dd7cddfSDavid du Colombier char *p, *q;
2757dd7cddfSDavid du Colombier Disk *d;
2767dd7cddfSDavid du Colombier
277766ccd67SDavid du Colombier d = mallocz(sizeof(*d), 1);
27859cc4ca5SDavid du Colombier if(d == nil)
27959cc4ca5SDavid du Colombier return nil;
28059cc4ca5SDavid du Colombier
2817dd7cddfSDavid du Colombier d->fd = d->wfd = d->ctlfd = -1;
2827dd7cddfSDavid du Colombier d->rdonly = rdonly;
2837dd7cddfSDavid du Colombier
2847dd7cddfSDavid du Colombier d->fd = open(disk, OREAD);
2857dd7cddfSDavid du Colombier if(d->fd < 0) {
2867dd7cddfSDavid du Colombier werrstr("cannot open disk file");
2877dd7cddfSDavid du Colombier free(d);
2887dd7cddfSDavid du Colombier return nil;
2897dd7cddfSDavid du Colombier }
2907dd7cddfSDavid du Colombier
2917dd7cddfSDavid du Colombier if(rdonly == 0) {
2927dd7cddfSDavid du Colombier d->wfd = open(disk, OWRITE);
2937dd7cddfSDavid du Colombier if(d->wfd < 0)
2947dd7cddfSDavid du Colombier d->rdonly = 1;
2957dd7cddfSDavid du Colombier }
2967dd7cddfSDavid du Colombier
2977dd7cddfSDavid du Colombier if(noctl)
2987dd7cddfSDavid du Colombier return openfile(d);
2997dd7cddfSDavid du Colombier
3003ff48bf5SDavid du Colombier p = malloc(strlen(disk) + 4); /* 4: slop for "ctl\0" */
30159cc4ca5SDavid du Colombier if(p == nil) {
30259cc4ca5SDavid du Colombier close(d->wfd);
30359cc4ca5SDavid du Colombier close(d->fd);
30459cc4ca5SDavid du Colombier free(d);
30559cc4ca5SDavid du Colombier return nil;
30659cc4ca5SDavid du Colombier }
3073ff48bf5SDavid du Colombier strcpy(p, disk);
3087dd7cddfSDavid du Colombier
3097dd7cddfSDavid du Colombier /* check for floppy(3) disk */
3107dd7cddfSDavid du Colombier if(strlen(p) >= 7) {
3117dd7cddfSDavid du Colombier q = p+strlen(p)-7;
3127dd7cddfSDavid du Colombier if(q[0] == 'f' && q[1] == 'd' && isdigit(q[2]) && strcmp(q+3, "disk") == 0) {
3137dd7cddfSDavid du Colombier strcpy(q+3, "ctl");
3147dd7cddfSDavid du Colombier if((d->ctlfd = open(p, ORDWR)) >= 0) {
3157dd7cddfSDavid du Colombier *q = '\0';
3167dd7cddfSDavid du Colombier d->prefix = p;
3177dd7cddfSDavid du Colombier d->type = Tfloppy;
3187dd7cddfSDavid du Colombier return openfile(d);
3197dd7cddfSDavid du Colombier }
3207dd7cddfSDavid du Colombier }
3217dd7cddfSDavid du Colombier }
3227dd7cddfSDavid du Colombier
3237dd7cddfSDavid du Colombier /* attempt to find sd(3) disk or partition */
3247dd7cddfSDavid du Colombier if(q = strrchr(p, '/'))
3257dd7cddfSDavid du Colombier q++;
3267dd7cddfSDavid du Colombier else
3277dd7cddfSDavid du Colombier q = p;
3287dd7cddfSDavid du Colombier
3297dd7cddfSDavid du Colombier strcpy(q, "ctl");
3307dd7cddfSDavid du Colombier if((d->ctlfd = open(p, ORDWR)) >= 0) {
3317dd7cddfSDavid du Colombier *q = '\0';
3327dd7cddfSDavid du Colombier d->prefix = p;
3337dd7cddfSDavid du Colombier d->type = Tsd;
3349a747e4fSDavid du Colombier d->part = strdup(disk+(q-p));
3359a747e4fSDavid du Colombier if(d->part == nil){
3369a747e4fSDavid du Colombier close(d->ctlfd);
3379a747e4fSDavid du Colombier close(d->wfd);
3389a747e4fSDavid du Colombier close(d->fd);
3399a747e4fSDavid du Colombier free(p);
3409a747e4fSDavid du Colombier free(d);
3419a747e4fSDavid du Colombier return nil;
3429a747e4fSDavid du Colombier }
3437dd7cddfSDavid du Colombier return opensd(d);
3447dd7cddfSDavid du Colombier }
3457dd7cddfSDavid du Colombier
3463ff48bf5SDavid du Colombier *q = '\0';
3473ff48bf5SDavid du Colombier d->prefix = p;
3487dd7cddfSDavid du Colombier /* assume we just have a normal file */
3497dd7cddfSDavid du Colombier d->type = Tfile;
3507dd7cddfSDavid du Colombier return openfile(d);
3517dd7cddfSDavid du Colombier }
352