port-arm/60193: olimex a64 - no carrier with emac0 ethernet

["nia%pkgsrc.org@localhost via gnats" <gnats-admin%NetBSD.org@localhost>]

>Number:         60193
>Category:       port-arm
>Synopsis:       olimex a64 - no carrier with emac0 ethernet
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-arm-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Apr 16 06:50:00 +0000 2026
>Originator:     nia
>Release:        
>Organization:
The NoNetBSD Foundation
>Environment:
NetBSD arm64 11.99.5 NetBSD 11.99.5 (GENERIC64) #0: Wed Apr 15 16:10:35 UTC 2026  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/evbarm/compile/GENERIC64 evbarm
>Description:
The device is never able to get a carrier, but is fully functional on
Olimex's official Linux image.

Starting dhcpcd.
dhcpcd-10.3.1 starting
DUID 00:01:blah
emac0: waiting for carrier
emac0: carrier acquired
emac0: IAID aa:blah
emac0: adding address fe80::d7a0:425e:74e4:eb0e
emac0: carrier lost - roaming
timed out

$ ifconfig
emac0: flags=0x8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        capabilities=0x3f00<IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx,TCP4CSUM_Tx>
        capabilities=0x3f00<UDP4CSUM_Rx,UDP4CSUM_Tx>
        enabled=0
        ec_capabilities=0x1<VLAN_MTU>
        ec_enabled=0
        address: 02:ba:xx:xx:xx:xx
        media: Ethernet autoselect (none)
        status: no carrier
        inet6 fe80::d7a0:425e:74e4:eb0e%emac0/64 flags 0x8<DETACHED> scopeid 0x

[     1.000004] emac0 at simplebus1: EMAC
[     1.000004] emac0: Ethernet address 02:ba:xx:xx:xx:xx
[     1.000004] emac0: interrupting on GIC irq 114
[     1.000004] ukphy0 at emac0 phy 1: OUI 0x0010a1, model 0x0022, rev. 2

Full dmesg for the board: https://dmesgd.nycbug.org/dmesgd?do=view&id=8914
>How-To-Repeat:
try to wait for dhcpcd, leave disappointed
>Fix:
might be a problem with the device tree

as temporary solution, attach axe0 over USB