### Author:  [@joema](https://community.solid-run.com/u/joema)
#### Post date: [August 2, 2023, 4:33pm UTC](https://community.solid-run.com/t/kernel-does-not-see-mac-address-set-by-u-boot/697/1 "2023-08-02T16:33:34Z")
Hi,
We are trying to set the mac address but it seems the kernel does not see it:
Setting in eeprom works fine:
=\> tlv\_eeprom set 0x24 00:23:45:67:89:AB
=\> tlv\_eeprom set 0x2A 2
=\> tlv\_eeprom write
Programming passed.
After boot u-boot seems to see this fine too:
=\> tlv\_eeprom
TLV: 0
TlvInfo Header:
Id String: TlvInfo
Version: 1
Total Length: 18
TLV Name Code Len Value
* * *
Base MAC Address 0x24 6 00:23:45:67:89:AB
MAC Addresses 0x2A 2 2
CRC-32 0xFE 4 0x35506F3A
Checksum is valid.
=\> printenv
…
eth1addr=00:23:45:67:89:AC
ethaddr=00:23:45:67:89:AB
…
But after booting the kernel we see a different mac address:
```auto
# ip a
...
4: eth0: mtu 1500 qdisc mq state UP group default qlen 1000
link/ether f2:ba:fe:48:11:74 brd ff:ff:ff:ff:ff:ff
inet 192.168.68.69/22 metric 1024 brd 192.168.71.255 scope global dynamic eth0
valid_lft 7190sec preferred_lft 7190sec
inet6 fe80::f0ba:feff:fe48:1174/64 scope link
valid_lft forever preferred_lft forever
```
Which seems to be random…
What are we missing? How does the kernel read the mac address from u-boot? something isn’t working (we use the latest version of kernel/u-boot built by the runme.sh build script).
---
### Author:  [@joema](https://community.solid-run.com/u/joema)
#### Post date: [August 3, 2023, 9:13am UTC](https://community.solid-run.com/t/kernel-does-not-see-mac-address-set-by-u-boot/697/2 "2023-08-03T09:13:17Z")
Inside u-boot/board/freescale/lx2160a/lx2160a.c I do see this function:
```auto
void fdt_fixup_board_enet(void *fdt)
{
int offset;
offset = fdt_path_offset(fdt, "/soc/fsl-mc");
if (offset < 0)
offset = fdt_path_offset(fdt, "/fsl-mc");
if (offset < 0) {
printf("%s: fsl-mc node not found in device tree (error %d)\n",
__func__ , offset);
return;
}
if (get_mc_boot_status() == 0 &&
(is_lazy_dpl_addr_valid() || get_dpl_apply_status() == 0)) {
fdt_status_okay(fdt, offset);
#ifndef CONFIG_DM_ETH
fdt_fixup_board_phy(fdt);
#else
if (IS_ENABLED(CONFIG_TARGET_LX2160ARDB))
fdt_fixup_board_phy_revc(fdt);
#endif
} else {
fdt_status_fail(fdt, offset);
}
}
```
We do seem to have CONFIG\_DM\_ETH defined, so the first fixup isn’t called. We do not seem to have CONFIG\_TARGET\_LX2160ARDB defined though - we have CONFIG\_TARGET\_LX2160ACEX7=y - so the 2nd fixup isn’t called as well.
Checking the older SolidRun release we were using so far, I see that it had a slightly different fixup u-boot function, with no #ifdefs:
```auto
void fdt_fixup_board_enet(void *fdt)
{
int offset;
offset = fdt_path_offset(fdt, "/soc/fsl-mc");
if (offset < 0)
offset = fdt_path_offset(fdt, "/fsl-mc");
if (offset < 0) {
printf("%s: fsl-mc node not found in device tree (error %d)\n",
__func__ , offset);
return;
}
if (get_mc_boot_status() == 0 &&
(is_lazy_dpl_addr_valid() || get_dpl_apply_status() == 0)) {
fdt_status_okay(fdt, offset);
fdt_fixup_board_phy(fdt);
} else {
fdt_status_fail(fdt, offset);
}
}
```
any idea how this should work in the latest SolidRun release and what do we need to further check?
Thanks
---
### Author:  [@jnettlet](https://community.solid-run.com/u/jnettlet)
#### Post date: [August 3, 2023, 9:40am UTC](https://community.solid-run.com/t/kernel-does-not-see-mac-address-set-by-u-boot/697/3 "2023-08-03T09:40:39Z")
The general consensus from the developer working on u-boot for the lx2160a is that the fdt\_fixup does matching of MAC → address, so the device-tree is not updated properly with the MAC for the onboard NIC as it is MAC 17 and you only have 2 MACs setup. You can verify this by dumping the device-tree in Linux and verifying this. Short term you can set the number of MACs in the TLV to be 17, but we will work on a patch to refine NXP’s code.
---
### Author:  [@joema](https://community.solid-run.com/u/joema)
#### Post date: [August 3, 2023, 10:07am UTC](https://community.solid-run.com/t/kernel-does-not-see-mac-address-set-by-u-boot/697/4 "2023-08-03T10:07:59Z")
Thanks! Checking this, I have set:
```auto
=> tlv_eeprom set 0x24 00:23:45:67:89:00
=> tlv_eeprom set 0x2A 17
=> tlv_eeprom write
Programming passed.
=> tlv_eeprom
TLV: 0
TlvInfo Header:
Id String: TlvInfo
Version: 1
Total Length: 18
TLV Name Code Len Value
-------------------- ---- --- -----
Base MAC Address 0x24 6 00:23:45:67:89:00
MAC Addresses 0x2A 2 17
CRC-32 0xFE 4 0x6E9CF587
Checksum is valid.
```
U-boot then tells me during boot that:
```auto
Net: eth0: DPMAC3@xgmii, eth1: DPMAC4@xgmii, eth2: DPMAC5@xgmii, eth3: DPMAC6@xgmii, eth4: DPMAC7@xgmii, eth5: DPMAC8@xgmii, eth6: DPMAC9@xgmii, eth7: DPMAC10@xgmii, eth8: DPMAC17@rgmii-id [PRIME]
```
So it seems dpmac17 gets the 9th entry.
Booting the kernel and checking the address of eth0 validates this:
```auto
# ip a show eth0
4: eth0: mtu 1500 qdisc mq state UP group default qlen 1000
link/ether 00:23:45:67:89:08 brd ff:ff:ff:ff:ff:ff
inet 192.168.68.64/22 metric 1024 brd 192.168.71.255 scope global dynamic eth0
valid_lft 6609sec preferred_lft 6609sec
inet6 fe80::223:45ff:fe67:8908/64 scope link
valid_lft forever preferred_lft forever
```
But the question is how can I give eth0 a specific address? let’s say I need it to be 00:23:45:67:89:00 and not 00:23:45:67:89:08
---
### Author:  [@jnettlet](https://community.solid-run.com/u/jnettlet)
#### Post date: [August 3, 2023, 10:38am UTC](https://community.solid-run.com/t/kernel-does-not-see-mac-address-set-by-u-boot/697/5 "2023-08-03T10:38:18Z")
> [@joema](#):
>
> `fdt_fixup_board_enet`
There is not way to do this via the existing mechanisms. You could create a custom function for u-boot that specifically patches the rgmii node to use the first MAC address and then start from MAC + 1 for the other interfaces.
---
### Author:  [@joema](https://community.solid-run.com/u/joema)
#### Post date: [August 3, 2023, 10:39am UTC](https://community.solid-run.com/t/kernel-does-not-see-mac-address-set-by-u-boot/697/6 "2023-08-03T10:39:00Z")
ok it’s a bit awkward, but if I want eth0 to have 00:23:45:67:8a:00 then I need to set:
=\> tlv\_eeprom set 0x24 00:23:45:67:89:F8
=\> tlv\_eeprom set 0x2A 9
then eth0 will get the 9th entry after F8 which is 00.
hope i’m not missing some other more elegant way.
thanks for the help!
---
### Author:  [@jnettlet](https://community.solid-run.com/u/jnettlet)
#### Post date: [August 3, 2023, 10:40am UTC](https://community.solid-run.com/t/kernel-does-not-see-mac-address-set-by-u-boot/697/7 "2023-08-03T10:40:04Z")
Without patching the existing u-boot code, then yes that is the only way.