docs/155989: Fix offset in boot.config(5)

[Garrett Cooper]

>Number:         155989
>Category:       docs
>Synopsis:       Fix offset in boot.config(5)
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-doc
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Mar 28 08:50:10 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator:     Garrett Cooper
>Release:        CURRENT
>Organization:
n/a
>Environment:
N/A
>Description:
The following is patch fixes the documentation for boot.config(5) as the indexes are incorrect per boot(8):

    bios_drive:interface(unit,[slice,]part)filename [-aCcDdghmnPprsv]
            [-Sspeed]
            Specify boot file and flags.

            bios_drive
                    The drive number as recognized by the BIOS.  0 for the
                    first drive, 1 for the second drive, etc.

I submitted it directly to danger@, but he suggested I create a PR for it.
>How-To-Repeat:

>Fix:


Patch attached with submission follows:

Index: share/man/man5/boot.config.5
===================================================================
--- share/man/man5/boot.config.5	(revision 220091)
+++ share/man/man5/boot.config.5	(working copy)
@@ -80,18 +80,19 @@
 .Pp
 The command:
 .Bd -literal -offset indent
-# echo "1:ad(1,a)/boot/loader" > /boot.config
+# echo "0:ad(1,a)/boot/loader" > /boot.config
 .Ed
 .Pp
 will instruct the second stage of
 .Xr boot 8
-on the first disk to boot with the third
-.Xr boot 8
-stage from the second disk.
+located on the second disk recognized by the BIOS, to boot via
+.Xr loader 8
+located on the first partition of the second non-floppy, non-SCSI disk
+recognized by the BIOS.
 .Pp
 The command:
 .Bd -literal -offset indent
-# echo "1:ad(1,a)/boot/loader -P" > /boot.config
+# echo "0:ad(1,a)/boot/loader -P" > /boot.config
 .Ed
 .Pp
 will do both of the above.


>Release-Note:
>Audit-Trail:
>Unformatted: