LDPUBLIC32 dsk_err_t LDPUBLIC16 dsk_getgeom(DSK_DRIVER *self, DSK_GEOMETRY *geom)
{
DRV_CLASS *dc;
dsk_err_t e;
if (!self || !geom || !self->dr_class) return DSK_ERR_BADPTR;
/* Check if the driver has overridden this function. If it has,
* then use its geometry probe, which is probably more limited. */
dc = self->dr_class;
memset(geom, 0, sizeof(*geom));
if (dc->dc_getgeom)
{
e = (dc->dc_getgeom)(self, geom);
if (e != DSK_ERR_NOTME && e != DSK_ERR_NOTIMPL) return e;
}
return dsk_defgetgeom(self, geom);
}
/* Get drive geometry */
dsk_err_t ldbsdisk_getgeom(DSK_DRIVER *pdriver, DSK_GEOMETRY *geom)
{
dsk_err_t err, err2;
LDBSDISK_DSK_DRIVER *self;
GETGEOM_STATS stats;
int n, count = -1;
DC_CHECK(pdriver)
self = (LDBSDISK_DSK_DRIVER *)pdriver;
/* Firstly try the default LibDsk geometry probe */
err = dsk_defgetgeom(pdriver, geom);
if (!err) return DSK_ERR_OK;
/* If that fails, see if the LDBS file describes its own geometry */
err2 = ldbs_get_geometry(self->ld_store, geom);
if (err2) return err2;
/* If it populated 'geom', it does. Otherwise no dice. */
if (geom->dg_cylinders && geom->dg_heads &&
geom->dg_sectors && geom->dg_secsize)
{
return DSK_ERR_OK;
}
/* This was in imd_geom() in previous versions. Basically, a
* fully-populated LDBS file contains enough information to
* give us a decent chance at determining the drive geometry
* ourselves. */
memset(&stats, 0, sizeof(stats));
dg_stdformat(&stats.dg, FMT_180K, NULL, NULL);
stats.minsec[0] = stats.minsec[1] = 256;
stats.maxsec[0] = stats.maxsec[1] = 0;
err = ldbs_all_sectors(self->ld_store, getgeom_callback,
SIDES_ALT, &stats);
if (err) return DSK_ERR_BADFMT;
/* Report the most frequent sector size */
for (n = 0; n < 8; n++)
{
if (stats.secsizes[n] > count)
{
count = stats.secsizes[n];
stats.dg.dg_secsize = 128 << n;
}
}
stats.dg.dg_secbase = stats.minsec[0];
/* Check for an 'extended surface' format: 2 heads, the
* sector ranges on each side are disjoint, and sectors on head 1
* are labelled as head 0 */
if (stats.dg.dg_heads == 2 && (stats.maxsec[0] + 1 ==
stats.minsec[1]) && stats.extsurface)
{
stats.dg.dg_sidedness = SIDES_EXTSURFACE;
}
if (stats.dg.dg_cylinders == 0 || stats.dg.dg_sectors == 0)
{
return DSK_ERR_BADFMT;
}
memcpy(geom, &stats.dg, sizeof(*geom));
return DSK_ERR_OK;
}
