I am working to support portability of disks from one architecture to
another---for example, i386 to evbmips.

Here is a routine that I wrote to hunt a disk's partition table for the
"raw" partition.  The routine prefers the architecture's raw partition
(RAW_PART'th partition) but, allowing for the possibility that the
RAW_PART'th partition does not span the disk, searches for a partition
that does.  What do you think, do I select the raw partition using the
right criteria?

/* Search for the raw partition.  Prefer the architecture's
 * raw partition (RAW_PART), but if it does not span the entire
 * disk, choose the first unused (FS_UNUSED) partition that does,
 * or else choose the first partition that spans the disk.
 */
static int
dkwedge_compute_rawpart(const struct disk *pdk)
{
	int i;
	const struct disklabel *d;
	const struct partition *p;

	d = pdk->dk_label;

	if (RAW_PART < d->d_npartitions) {
		p = &d->d_partitions[RAW_PART];
		if (p->p_offset == 0 && p->p_size == d->d_secperunit)
			return RAW_PART;
	}
	for (i = 0; i < d->d_npartitions; i++) {
		p = &d->d_partitions[i];
		if (p->p_offset == 0 && p->p_size == d->d_secperunit &&
		    p->p_fstype == FS_UNUSED)
			return i;
	}
	for (i = 0; i < d->d_npartitions; i++) {
		p = &d->d_partitions[i];
		if (p->p_offset == 0 && p->p_size == d->d_secperunit)
			return i;
	}
	return -1;
}

Dave

-- 
David Young             OJC Technologies
dyoung@ojctech.com      Urbana, IL * (217) 278-3933