The CuBox-i4 Pro booted Kernel 4.0-rc1 OK, but – although eth0 was present – there was no network connection possible..

I found a similar problem described on the Linux Arm Kernel mailing list:  http://lists.infradead.org/pipermail/linux-arm-kernel/2015-February/325249.html

According to the info there, I changed linux/arch/arm/mach-imx/mach-imx6q.c as follows:

Around line 214, change

clksel = ptp_clk == enet_ref ? IMX6Q_GPR1_ENET_CLK_SEL_ANATOP :
                                    IMX6Q_GPR1_ENET_CLK_SEL_PAD;

to

clksel = ptp_clk != enet_ref ? IMX6Q_GPR1_ENET_CLK_SEL_ANATOP :
                                    IMX6Q_GPR1_ENET_CLK_SEL_PAD;

Recompile / install, and networking now works correctly..

......................
fec 2188000.ethernet eth0: Link is Up - 1Gbps/Full - flow control rx/tx
IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
......................

Fedora release 22 (Twenty Two)
Kernel 4.0.0-rc1 on an armv7l (ttymxc0)
.......................
[root@rgcubox ~]# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
default dsl_router 0.0.0.0 UG 100 0 0 eth0
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
192.168.0.0 0.0.0.0 255.255.255.0 U 100 0 0 eth0
[root@rgcubox ~]# ping rglinux-i7
PING rglinux-i7 (192.168.0.2) 56(84) bytes of data.
64 bytes from rglinux-i7 (192.168.0.2): icmp_seq=1 ttl=64 time=0.341 ms
64 bytes from rglinux-i7 (192.168.0.2): icmp_seq=2 ttl=64 time=0.173 ms
64 bytes from rglinux-i7 (192.168.0.2): icmp_seq=3 ttl=64 time=0.171 ms
--- rglinux-i7 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 1999ms
rtt min/avg/max/mdev = 0.171/0.228/0.341/0.080 ms

So – I now have Kernel 4.0-rc1 running successfully on the CuBox-i4 Pro..

Robert Gadsdon.  February 24, 2015.