Set default pxeboot vfs.root.mountfrom to nfs?

[Doug Ambrisko]

Garrett Cooper writes:
| Hi Hackers,
|     I realize this is a trivial patch, but it's a minor item that I
| found kind of fascinating (and not thoroughly documented elsewhere
| because many examples are booting mfsroots instead of directly booting
| off nfs roots), but I'm proposing that pxeboot default to
| vfs.root.mountfrom="nfs" to reduce the need for special case
| loader.conf files just for pxe booting (and thus, enable
| out-of-the-box netbooting ^o^!!!).
|     Thoughts?
| 
| Index: boot/i386/libi386/pxe.c
| ===================================================================
| --- boot/i386/libi386/pxe.c	(revision 209563)
| +++ boot/i386/libi386/pxe.c	(working copy)
| @@ -308,6 +308,7 @@
|  		}
|  		setenv("boot.nfsroot.server", inet_ntoa(rootip), 1);
|  		setenv("boot.nfsroot.path", rootpath, 1);
| +		setenv("vfs.root.mountfrom", "nfs", 0);
|  		setenv("dhcp.host-name", hostname, 1);
|  	}
|      }

Interesting, are you looking at my patch from work or came up with
the same thing?  We had this patch here for years.

I haven't checked it in due to tracking done why it wasn't done in
the first place so I didn't break any assumptions.  FWIW, I have seen
no issues with patch in either NFS boots or MFS roots.

Doug A.