/*
* read or write to floppy. try up to three times.
*/
static long
floppyxfer(FDrive *dp, int cmd, void *a, long off, long n)
{
long offset;
int tries;
if(off >= dp->t->cap)
return 0;
if(off + n > dp->t->cap)
n = dp->t->cap - off;
/* retry on error (until it gets ridiculous) */
for(tries = 0; tries < dp->maxtries; tries++) {
dp->len = n;
if(pcfloppyseek(dp, off) < 0) {
DPRINT("xfer: seek failed\n");
dp->confused = 1;
continue;
}
/*
* set up the dma (dp->len may be trimmed)
*/
dp->len = dmasetup(DMAchan, a, dp->len, cmd==Fread);
if(dp->len < 0) {
buggery:
dmaend(DMAchan);
continue;
}
/*
* start operation
*/
fl.ncmd = 0;
fl.cmd[fl.ncmd++] = cmd | (dp->t->heads > 1 ? Fmulti : 0);
fl.cmd[fl.ncmd++] = (dp->thead<<2) | dp->dev;
fl.cmd[fl.ncmd++] = dp->tcyl;
fl.cmd[fl.ncmd++] = dp->thead;
fl.cmd[fl.ncmd++] = dp->tsec;
fl.cmd[fl.ncmd++] = dp->t->bcode;
fl.cmd[fl.ncmd++] = dp->t->sectors;
fl.cmd[fl.ncmd++] = dp->t->gpl;
fl.cmd[fl.ncmd++] = 0xFF;
if(floppycmd() < 0)
goto buggery;
/*
* give bus to DMA, floppyintr() will read result
*/
floppywait(0);
dmaend(DMAchan);
/*
* check for errors
*/
if(fl.nstat < 7) {
DPRINT("xfer: confused\n");
fl.confused = 1;
continue;
}
if((fl.stat[0] & Codemask)!=0 || fl.stat[1] || fl.stat[2]) {
DPRINT("xfer: failed %ux %ux %ux\n", fl.stat[0],
fl.stat[1], fl.stat[2]);
DPRINT("offset %lud len %ld\n", off, dp->len);
if((fl.stat[0]&Codemask)==Cmdexec && fl.stat[1]==Overrun) {
DPRINT("DMA overrun: retry\n");
} else
dp->confused = 1;
continue;
}
/*
* check for correct cylinder
*/
offset = fl.stat[3] * dp->t->heads + fl.stat[4];
offset = offset*dp->t->sectors + fl.stat[5] - 1;
offset = offset * c2b[fl.stat[6]];
if(offset != off+dp->len) {
DPRINT("xfer: ends on wrong cyl\n");
dp->confused = 1;
continue;
}
dp->lasttouched = m->ticks;
dp->maxtries = 20;
return dp->len;
}
return -1;
}
/*
* 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();
}
