Finally implement the "auto" disktype. It attempts to get all the

required information from the driver, and produce a virgin disklabel
for it.  The latter might be further edited with `disklabel -e' to
satisfy the user's need.

The magic sequence is:

	disklabel -r -w sdX auto
	disklabel -e sdX

1 files changed, 21 insertions, 0 deletions

diff --git a/sbin/bsdlabel/bsdlabel.8 b/sbin/bsdlabel/bsdlabel.8
index bf14e0f..1cc33ab 100644
--- a/sbin/bsdlabel/bsdlabel.8
+++ b/sbin/bsdlabel/bsdlabel.8
@@ -161,6 +161,21 @@ If the disk does not already have a label, the
 flag must be used.
 In either case, the kernel's in-core label is replaced.
 .Pp
+For a virgin disk that is not known to
+.Xr disktab 5 ,
+.Ar disktype
+can be specified as
+.Dq auto .
+In this case, the driver is requested to produce a virgin label for the
+disk.  This might or might not be successful, depending on whether the
+driver for the disk is able to get the required data without reading
+anything from the disk at all.  It will likely succeed for all SCSI
+disks, most IDE disks, and vnode devices.  Writing a label to the
+disk is the only supported operation, and the
+.Ar disk
+itself must be provided as the canonical name, i.e. not as a full
+path name.
+.Pp
 An existing disk label may be edited by using the
 .Fl e
 flag.
@@ -286,6 +301,12 @@ Read the on-disk label for sd0, edit it and reinstall in-core as well
 as on-disk.
 Existing bootstrap code is unaffected.
 .Pp
+.Dl disklabel -r -w sd0 auto
+.Pp
+Try to auto-detect the required information from sd0, and write a new
+label to the disk.  Use another disklabel -e command to edit the
+partitioning and file system information.
+.Pp
 .Dl disklabel -R sd0 mylabel
 .Pp
 Restore the on-disk and in-core label for sd0 from information in