/*
* check if the floppy has been replaced under foot. cause
* an error if it has.
*
* a seek and a read clears the condition. this was determined
* experimentally, there has to be a better way.
*
* if the read fails, cycle through the possible floppy
* density till one works or we've cycled through all
* possibilities for this drive.
*/
static void
changed(Chan *c, FDrive *dp)
{
ulong old;
FType *start;
/*
* if floppy has changed or first time through
*/
if((inb(Pdir)&Fchange) || dp->vers == 0){
DPRINT("changed\n");
fldump();
dp->vers++;
start = dp->t;
dp->maxtries = 3; /* limit it when we're probing */
/* floppyon will fail if there's a controller but no drive */
dp->confused = 1; /* make floppyon recal */
if(floppyon(dp) < 0)
error(Eio);
/* seek to the first track */
floppyseek(dp, dp->t->heads*dp->t->tsize);
while(waserror()){
/*
* if first attempt doesn't reset changed bit, there's
* no floppy there
*/
if(inb(Pdir)&Fchange)
nexterror();
while(++dp->t){
if(dp->t == &floppytype[nelem(floppytype)])
dp->t = floppytype;
if(dp->dt == dp->t->dt)
break;
}
floppydir[1+NFDIR*dp->dev].length = dp->t->cap;
/* floppyon will fail if there's a controller but no drive */
if(floppyon(dp) < 0)
error(Eio);
DPRINT("changed: trying %s\n", dp->t->name);
fldump();
if(dp->t == start)
nexterror();
}
/* if the read succeeds, we've got the density right */
floppyxfer(dp, Fread, dp->cache, 0, dp->t->tsize);
poperror();
dp->maxtries = 20;
}
old = c->qid.vers;
c->qid.vers = dp->vers;
if(old && old != dp->vers)
error(Eio);
}
/*
* check if the floppy has been replaced under foot. cause
* an error if it has.
*
* a seek and a read clears the condition. this was determined
* experimentally, there has to be a better way.
*
* if the read fails, cycle through the possible floppy
* density till one works or we've cycled through all
* possibilities for this drive.
*/
static int
changed(FDrive *dp)
{
FType *start;
/*
* if floppy has changed or first time through
*/
if((inb(Pdir)&Fchange) || dp->vers == 0) {
DPRINT("changed\n");
fldump();
dp->vers++;
floppysetdef(dp);
dp->maxtries = 3;
start = dp->t;
/* flopppyon fails if there's no drive */
dp->confused = 1; /* make floppyon recal */
if(floppyon(dp) < 0)
return -1;
pcfloppyseek(dp, dp->t->heads*dp->t->tsize);
while(floppyxfer(dp, Fread, dp->cache, 0, dp->t->tsize) <= 0) {
/*
* if the xfer attempt doesn't clear the changed bit,
* there's no floppy in the drive
*/
if(inb(Pdir)&Fchange)
return -1;
while(++dp->t) {
if(dp->t == &floppytype[nelem(floppytype)])
dp->t = floppytype;
if(dp->dt == dp->t->dt)
break;
}
/* flopppyon fails if there's no drive */
if(floppyon(dp) < 0)
return -1;
DPRINT("changed: trying %s\n", dp->t->name);
fldump();
if(dp->t == start)
return -1;
}
}
return 0;
}
long
floppyread(Fs *fs, void *a, long n)
{
FDrive *dp;
long rv, offset;
int sec, head, cyl;
long len;
uchar *aa;
aa = a;
dp = &fl.d[fs->dev];
offset = dp->offset;
floppyon(dp);
if(changed(dp))
return -1;
for(rv = 0; rv < n; rv += len) {
/*
* all xfers come out of the track cache
*/
dp->len = n - rv;
floppypos(dp, offset+rv);
cyl = dp->tcyl;
head = dp->thead;
len = dp->len;
sec = dp->tsec;
if(readtrack(dp, cyl, head) < 0)
break;
memmove(aa+rv, dp->cache + (sec-1)*dp->t->bytes, len);
}
dp->offset = offset+rv;
return rv;
}
static long
floppyread(Chan *c, void *a, long n, vlong off)
{
FDrive *dp;
long rv;
int sec, head, cyl;
long len;
uchar *aa;
ulong offset = off;
if(c->qid.type & QTDIR)
return devdirread(c, a, n, floppydir, 1+fl.ndrive*NFDIR, devgen);
rv = 0;
dp = &fl.d[c->qid.path & ~Qmask];
switch ((int)(c->qid.path & Qmask)) {
case Qdata:
islegal(offset, n, dp);
aa = a;
qlock(&fl);
if(waserror()){
qunlock(&fl);
nexterror();
}
floppyon(dp);
changed(c, dp);
for(rv = 0; rv < n; rv += len){
/*
* all xfers come out of the track cache
*/
dp->len = n - rv;
floppypos(dp, offset+rv);
cyl = dp->tcyl;
head = dp->thead;
len = dp->len;
sec = dp->tsec;
if(readtrack(dp, cyl, head) < 0)
break;
memmove(aa+rv, dp->cache + (sec-1)*dp->t->bytes, len);
}
qunlock(&fl);
poperror();
break;
case Qctl:
return readstr(offset, a, n, dp->t->name);
default:
panic("floppyread: bad qid");
}
return rv;
}
/*
* format a track
*/
static void
floppyformat(FDrive *dp, Cmdbuf *cb)
{
int cyl, h, sec;
ulong track;
uchar *buf, *bp;
FType *t;
/*
* set the type
*/
if(cb->nf == 2){
for(t = floppytype; t < &floppytype[nelem(floppytype)]; t++){
if(strcmp(cb->f[1], t->name)==0 && t->dt==dp->dt){
dp->t = t;
floppydir[1+NFDIR*dp->dev].length = dp->t->cap;
break;
}
}
if(t >= &floppytype[nelem(floppytype)])
error(Ebadarg);
} else if(cb->nf == 1){
floppysetdef(dp);
t = dp->t;
} else {
cmderror(cb, "invalid floppy format command");
SET(t);
}
/*
* buffer for per track info
*/
buf = smalloc(t->sectors*4);
if(waserror()){
free(buf);
nexterror();
}
/* force a recalibrate to cylinder 0 */
dp->confused = 1;
if(!waserror()){
floppyon(dp);
poperror();
}
/*
* format a track at time
*/
for(track = 0; track < t->tracks*t->heads; track++){
cyl = track/t->heads;
h = track % t->heads;
/*
* seek to track, ignore errors
*/
floppyseek(dp, track*t->tsize);
dp->cyl = cyl;
dp->confused = 0;
/*
* set up the dma (dp->len may be trimmed)
*/
bp = buf;
for(sec = 1; sec <= t->sectors; sec++){
*bp++ = cyl;
*bp++ = h;
*bp++ = sec;
*bp++ = t->bcode;
}
if(waserror()){
dmaend(DMAchan);
nexterror();
}
if(dmasetup(DMAchan, buf, bp-buf, 0) < 0)
error(Eio);
/*
* start operation
*/
fl.ncmd = 0;
fl.cmd[fl.ncmd++] = Fformat;
fl.cmd[fl.ncmd++] = (h<<2) | dp->dev;
fl.cmd[fl.ncmd++] = t->bcode;
fl.cmd[fl.ncmd++] = t->sectors;
fl.cmd[fl.ncmd++] = t->fgpl;
fl.cmd[fl.ncmd++] = 0x5a;
if(floppycmd() < 0)
error(Eio);
/* Poll ready bits and transfer data */
floppyexec((char *)buf, bp-buf, 0);
/*
* give bus to DMA, floppyintr() will read result
*/
floppywait(1);
dmaend(DMAchan);
poperror();
/*
* check for errors
*/
if(fl.nstat < 7){
DPRINT("format: confused\n");
fl.confused = 1;
error(Eio);
}
if((fl.stat[0]&Codemask)!=0 || fl.stat[1]|| fl.stat[2]){
DPRINT("format: failed %ux %ux %ux\n",
fl.stat[0], fl.stat[1], fl.stat[2]);
dp->confused = 1;
error(Eio);
}
}
free(buf);
dp->confused = 1;
poperror();
}
static long
floppywrite(Chan *c, void *a, long n, vlong off)
{
FDrive *dp;
long rv, i;
char *aa = a;
Cmdbuf *cb;
Cmdtab *ct;
ulong offset = off;
rv = 0;
dp = &fl.d[c->qid.path & ~Qmask];
switch ((int)(c->qid.path & Qmask)) {
case Qdata:
islegal(offset, n, dp);
qlock(&fl);
if(waserror()){
qunlock(&fl);
nexterror();
}
floppyon(dp);
changed(c, dp);
for(rv = 0; rv < n; rv += i){
floppypos(dp, offset+rv);
if(dp->tcyl == dp->ccyl)
dp->ccyl = -1;
i = floppyxfer(dp, Fwrite, aa+rv, offset+rv, n-rv);
if(i < 0)
break;
if(i == 0)
error(Eio);
}
qunlock(&fl);
poperror();
break;
case Qctl:
rv = n;
cb = parsecmd(a, n);
if(waserror()){
free(cb);
nexterror();
}
qlock(&fl);
if(waserror()){
qunlock(&fl);
nexterror();
}
ct = lookupcmd(cb, floppyctlmsg, nelem(floppyctlmsg));
switch(ct->index){
case CMeject:
floppyeject(dp);
break;
case CMformat:
floppyformat(dp, cb);
break;
case CMreset:
fl.confused = 1;
floppyon(dp);
break;
case CMdebug:
floppydebug = 1;
break;
case CMnodebug:
floppydebug = 0;
break;
}
poperror();
qunlock(&fl);
poperror();
free(cb);
break;
default:
panic("floppywrite: bad qid");
}
return rv;
}
