This works around a bootloader issue where every device
has the same lan/wan-mac 00:04:9f:ef:01:01 - with this patch
we read the macs from config-partition during initial network
setup. We have 9 valid macs stored in the partition, the
1st two are used for the radios, 3 and 4 are now used for WAN/LAN.
on an already setup / running device we can get the real macs with
. /lib/functions.sh
. /lib/functions/system.sh
echo "LAN = $(mtd_get_mac_binary config 338)"
echo "WAN = $(mtd_get_mac_binary config 344)"
see:
https://dev.openwrt.org/ticket/14714
from the ticket / user klondike:
U-Boot passed this commit ecd1a09b81http://u-boot.10912.n7.nabble.com/U-Boot-PATCH-mpc83xx-remove-hardcoded-network-addresses-from-config-files-td44372.html
I suppose to prevent this particular issue, but the WDR4900 may be using an old bootloader still affected.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
I have been checking the contents of the dtb on the flash, this particular bit is quite revealing:
ethernet@b0000 {
#address-cells = <0x1>;
#size-cells = <0x1>;
device_type = "network";
model = "eTSEC";
compatible = "fsl,etsec2";
fsl,num_rx_queues = <0x8>;
fsl,num_tx_queues = <0x8>;
local-mac-address = [00 00 00 00 00 00];
^^^^^^^^^^^^^^^^^
interrupt-parent = <0x2>;
phy-handle = <0x3>;
phy-connection-type = "rgmii-id";
ptimer-handle = <0x4>;
queue-group@0 {
#address-cells = <0x1>;
#size-cells = <0x1>;
reg = <0xb0000 0x1000>;
rx-bit-map = <0xff>;
tx-bit-map = <0xff>;
interrupts = <0x1d 0x2 0x1e 0x2 0x22 0x2>;
};
};
I also have been checking the live device map to find this:
root@GHS-AP3:~# hexdump -C /proc/device-tree/soc@ffe00000/ethernet@b0000/local-mac-address
00000000 00 04 9f ef 01 01 |......|
00000006
root@GHS-AP3:~# hexdump -C /proc/device-tree/soc@ffe00000/ethernet@b1000/local-mac-address
*
root@GHS-AP3:~# hexdump -C /proc/device-tree/soc@ffe00000/ethernet@b2000/local-mac-address
*
My conclussion is that U-Boot most likely finds the device and (as no valid MAC-address is provided)
falls back to the default MAC provided by the old code, the kernel then receives thee modified
device map from U-Boot and assumes this is the correct MAC for the device despite it obviously isn't.
This can be seen at
target/linux/mpc85xx/patches-3.10/140-powerpc-85xx-tl-wdr4900-v1-support.patch
The enetaddr is filled up by using the device tree data by the process_boot_dtb
function and used by the platform_fixups function to set the eth0 address
(by calling dt_fixup_mac_address_by_alias("ethernet0", enetaddr); ).
But instead we should be used the device address which to my understanding is
provided in the mtd.
Signed-off-by: Bastian Bittorf <bittorf@bluebottle.com>
SVN-Revision: 43074
c997410461