Random MAC address on my BeagleBone White

Random MAC address on my BeagleBone White

[Steven Rostedt]

Hi,

I'm using my BeagleBone White to debug some ftrace code and with the
help from people like Robert Nelson I was finally able to boot it and
test my kernel.

But I'm still having some other issues. The most annoying one is that
the new kernel assigns some random MAC address to my NIC and I can't
give my board the proper IP address via DHCP.

Seems there was talk about adding this via the device tree, but it was
rejected because U-Boot can do it. The problem I have is that U-Boot
doesn't!

I downloaded the latest U-Boot from git://git.denx.de/u-boot.git (Is
that the right place?) and had to tweak it so that I can boot a kernel
via tftp and still use the filesystem on the SD card.

When I place the 3.2 kernel that came with the board on my tftp server,
all works fine. I get the same MAC addr each boot and things just work.
But if I place the 3.16 kernel that I build on the tftp server, I get
some random MAC address, and then a dynamic IP to go with it :-(

This is in my dmesg:

[    2.304970] cpsw 4a100000.ethernet: Random MACID = 8a:fc:f5:aa:b6:e1

I can also see in the file arch/arm/boot/dts/am33xx.dtsi:


                        cpsw_emac0: slave at 4a100200 {
                                /* Filled in by U-Boot */
                                mac-address = [ 00 00 00 00 00 00 ];
                        };

Well, it's not filled in by U-Boot.

My question to all of you is, how do I fix this? I need a static mac
addr.

One way is that I might have to update that file myself with a temp
patch, but I think that's a hack and not something worth doing.

What's the proper way to have the board always come up with the same
MAC addr?

Thanks, this is rather annoying.

-- Steve

Random MAC address on my BeagleBone White

[Richard Cochran]

On Fri, Aug 15, 2014 at 01:42:21PM -0400, Steven Rostedt wrote:
> Thanks, this is rather annoying.

You must be new here ;)


Cheers,
Richard

Random MAC address on my BeagleBone White

[Anand Moon]

Hi Steven,

Please follow the bellow link to set mac address.

http://www.armadeus.com/wiki/index.php?title=Ethernet_MAC_address

-Anand Moon
On 8/15/2014 11:12 PM, Steven Rostedt wrote:
> Hi,
>
> I'm using my BeagleBone White to debug some ftrace code and with the
> help from people like Robert Nelson I was finally able to boot it and
> test my kernel.
>
> But I'm still having some other issues. The most annoying one is that
> the new kernel assigns some random MAC address to my NIC and I can't
> give my board the proper IP address via DHCP.
>
> Seems there was talk about adding this via the device tree, but it was
> rejected because U-Boot can do it. The problem I have is that U-Boot
> doesn't!
>
> I downloaded the latest U-Boot from git://git.denx.de/u-boot.git (Is
> that the right place?) and had to tweak it so that I can boot a kernel
> via tftp and still use the filesystem on the SD card.
>
> When I place the 3.2 kernel that came with the board on my tftp server,
> all works fine. I get the same MAC addr each boot and things just work.
> But if I place the 3.16 kernel that I build on the tftp server, I get
> some random MAC address, and then a dynamic IP to go with it :-(
>
> This is in my dmesg:
>
> [    2.304970] cpsw 4a100000.ethernet: Random MACID = 8a:fc:f5:aa:b6:e1
>
> I can also see in the file arch/arm/boot/dts/am33xx.dtsi:
>
>
>                          cpsw_emac0: slave at 4a100200 {
>                                  /* Filled in by U-Boot */
>                                  mac-address = [ 00 00 00 00 00 00 ];
>                          };
>
> Well, it's not filled in by U-Boot.
>
> My question to all of you is, how do I fix this? I need a static mac
> addr.
>
> One way is that I might have to update that file myself with a temp
> patch, but I think that's a hack and not something worth doing.
>
> What's the proper way to have the board always come up with the same
> MAC addr?
>
> Thanks, this is rather annoying.
>
> -- Steve
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Random MAC address on my BeagleBone White

[Steven Rostedt]

On Sat, 16 Aug 2014 00:02:19 +0530
Anand Moon <moon.linux@yahoo.com> wrote:

> Hi Steven,
> 
> Please follow the bellow link to set mac address.
> 
> http://www.armadeus.com/wiki/index.php?title=Ethernet_MAC_address
> 
> -Anand Moon

Hi,

My U-Boot already has a ethaddr defined. It's what is used by the
default kernel that came with the board (3.2).

U-Boot# printenv
[...]
ethaddr=d4:94:a1:8b:ec:78

The problem is that this is ignored by the latest kernel and it
replaces it with some random mac.

Note, I boot via bootp, thus it has to have a mac. That mac is what
tells my dhcp server what kernel image to load this board.

-- Steve

Random MAC address on my BeagleBone White

[Markus Pargmann]

Hi Steven,

On Fri, Aug 15, 2014 at 01:42:21PM -0400, Steven Rostedt wrote:
> Hi,
> 
> I'm using my BeagleBone White to debug some ftrace code and with the
> help from people like Robert Nelson I was finally able to boot it and
> test my kernel.
> 
> But I'm still having some other issues. The most annoying one is that
> the new kernel assigns some random MAC address to my NIC and I can't
> give my board the proper IP address via DHCP.
> 
> Seems there was talk about adding this via the device tree, but it was
> rejected because U-Boot can do it. The problem I have is that U-Boot
> doesn't!
> 
> I downloaded the latest U-Boot from git://git.denx.de/u-boot.git (Is
> that the right place?) and had to tweak it so that I can boot a kernel
> via tftp and still use the filesystem on the SD card.
> 
> When I place the 3.2 kernel that came with the board on my tftp server,
> all works fine. I get the same MAC addr each boot and things just work.
> But if I place the 3.16 kernel that I build on the tftp server, I get
> some random MAC address, and then a dynamic IP to go with it :-(
> 
> This is in my dmesg:
> 
> [    2.304970] cpsw 4a100000.ethernet: Random MACID = 8a:fc:f5:aa:b6:e1
> 
> I can also see in the file arch/arm/boot/dts/am33xx.dtsi:
> 
> 
>                         cpsw_emac0: slave at 4a100200 {
>                                 /* Filled in by U-Boot */
>                                 mac-address = [ 00 00 00 00 00 00 ];
>                         };
> 
> Well, it's not filled in by U-Boot.
> 
> My question to all of you is, how do I fix this? I need a static mac
> addr.
> 
> One way is that I might have to update that file myself with a temp
> patch, but I think that's a hack and not something worth doing.
> 
> What's the proper way to have the board always come up with the same
> MAC addr?

The am335x SoC already has 4 registers which contain two unique vendor
MAC addresses, so they should be used automatically instead of a random
one.

As you mentioned above, I sent a series to read and use those addresses
in the linux kernel. There were some problems with the series which I
fixed to send a new version of the series, but I didn't send it yet. I
will try to resend it tomorrow and Cc you. It would be great if you
could test it.

As far as I know, barebox also works with the beaglebone white and it
should set the correct MAC address as well. So if you need the same IP
address in linux as in the bootloader, you could try barebox.

Best Regards,

Markus

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
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Random MAC address on my BeagleBone White

[Steven Rostedt]

On Fri, 15 Aug 2014 20:49:11 +0200
Markus Pargmann <mpa@pengutronix.de> wrote:

> Hi Steven,
> 
 
> The am335x SoC already has 4 registers which contain two unique vendor
> MAC addresses, so they should be used automatically instead of a random
> one.
> 
> As you mentioned above, I sent a series to read and use those addresses
> in the linux kernel. There were some problems with the series which I
> fixed to send a new version of the series, but I didn't send it yet. I
> will try to resend it tomorrow and Cc you. It would be great if you
> could test it.
> 

Yep, but I don't work on weekends (Chief Home Officer's orders). Well,
I should say, I don't do computer work on weekends. House work on the
other hand, plenty (Again, the CHO's orders). It will have to wait till
Monday.

> As far as I know, barebox also works with the beaglebone white and it
> should set the correct MAC address as well. So if you need the same IP
> address in linux as in the bootloader, you could try barebox.

Maybe I'll give it a try. But if your stuff works I'll be fine with
that.

Thanks! Hopefully I'll be using this board in my ktest tutorial at
ELCEU in October.

-- Steve