NFS Root with Raspberry Pi (nfs_diskless: no interface)

[Daniel Braniss]

> On 25 Sep 2015, at 03:54, Ian Lepore <ian at FreeBSD.org> wrote:
> 
> On Thu, 2015-09-24 at 19:54 +0200, Hans Petter Selasky wrote:
>> On 09/24/15 18:36, Randy Westlund wrote:
>>> On Thu, Sep 24, 2015 at 08:37:06AM -0600, Ian Lepore wrote:
>> 
>>>>> [orig problem description: basically nfsroot without BOOTP fails]
>> 
>>>> Try setting boot.netif.name="ue0" in loader.conf.  I've never tried
>>>> that, but in looking at the code, there's some chance it could work.  :)
>>>> 
>>>> What I do is put these options into my RPi kernel config:
>>>> 
>>>> options 	BOOTP
>>>> options 	BOOTP_NFSROOT
>>>> options 	BOOTP_NFSV3
>>>> options 	BOOTP_WIRED_TO=ue0
>>>> 
>>>> But this requires configuring a bootp or dhcp server to provide the
>>>> info.  It should be possible to netboot without using BOOTP.
>>>> 
>>>> -- Ian
>>> 
>>> No luck with boot.netif.name.
>>> 
>>> I'm using the kernel that comes in the FreeBSD RPI-B disk image.  Is
>>> there a way to see what it was built with?  I tried running strings on
>>> the kernel, but I'm not sure what to look for.  Otherwise I guess I'll
>>> build one myself.
>>> 
>>> Randy
>>> 
>> 
>> Hi,
>> 
>> The problem is that the code in:
>> 
>> sys/nfs/bootp_subr.c: SYSINIT(bootp_rootconf, SI_SUB_ROOT_CONF, 
>> SI_ORDER_FIRST, bootpc_init, NULL);
>> 
>> doesn't wait for the USB ethernet device to be enumerated. Only the 
>> vfs_mountroot() code which is running from the init-process does so.
>> 
>> Not sure what the best way to solve this is. Try putting:
>> 
>> pause("W", hz * 4);
>> 
>> Into the beginning of the "bootpc_init()" function.
>> 
>> --HPS
> 
> I had time to look into this today.  The bootpc_init() routine *does*
> wait for an interface to appear.  The problem in this case is that BOOTP
> isn't involved, and the nfs_setup_diskless() routine doesn't have a
> similar wait loop for slow interfaces.  The attached patch adds it, and
> with it I can nfsmount root on my RPi without using the BOOTP_foo
> options I listed above.
> 
> Rick, does this patch look okay to you?  If no objections, I'll commit
> this asap.
> 
> -- Ian
> 
> Index: sys/nfs/nfs_diskless.c
> ===================================================================
> --- sys/nfs/nfs_diskless.c	(revision 288203)
> +++ sys/nfs/nfs_diskless.c	(working copy)
> @@ -57,6 +57,8 @@ __FBSDID("$FreeBSD$");
> #include <nfsclient/nfs.h>
> #include <nfs/nfsdiskless.h>
> 
> +#define	IFACE_TIMEOUT_SECS	10 /* Timeout for interface to appear. */
> +
> static int inaddr_to_sockaddr(char *ev, struct sockaddr_in *sa);
> static int hwaddr_to_sockaddr(char *ev, struct sockaddr_dl *sa);
> static int decode_nfshandle(char *ev, u_char *fh, int maxfh);
> @@ -170,6 +172,7 @@ nfs_setup_diskless(void)
> 	char *cp;
> 	int cnt, fhlen, is_nfsv3;
> 	uint32_t len;
> +	time_t timeout_at;
> 
> 	if (nfs_diskless_valid != 0)
> 		return;
> @@ -214,6 +217,8 @@ nfs_setup_diskless(void)
> 		return;
> 	}
> 	ifa = NULL;
> +	timeout_at = time_uptime + IFACE_TIMEOUT_SECS;
> +retry:
> 	CURVNET_SET(TD_TO_VNET(curthread));
> 	IFNET_RLOCK();
> 	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
> @@ -234,6 +239,10 @@ nfs_setup_diskless(void)
> 	}
> 	IFNET_RUNLOCK();
> 	CURVNET_RESTORE();
> +	if (time_uptime < timeout_at) {
> +		pause("nfssdl", hz / 5);
> +		goto retry;
> +	}
> 	printf("nfs_diskless: no interface\n");
> 	return;	/* no matching interface */
> match_done:
> _______________________________________________

hi Ian,
can you help me here?
I need the magics to get ubldr to boot from the net,
i’m using an image built via crochet. 

cheers,
	danny