[SOLVED] BeagleBone White UARTs not active.

[mfs]

I'm running 3.17.1 and trying to use the on board UARTs without luck. The device nodes exist and dmesg shows that everything looks ok:
$this->bbcode_second_pass_code('', '
[root@calcium ~]# ls -lh /dev/ttyO?
crw--w---- 1 root tty 248, 0 Oct 27 09:37 /dev/ttyO0
crw-rw---- 1 root uucp 248, 1 Oct 27 09:37 /dev/ttyO1
crw-rw---- 1 root uucp 248, 2 Oct 27 09:37 /dev/ttyO2
crw-rw---- 1 root uucp 248, 4 Oct 27 09:37 /dev/ttyO4
crw-rw---- 1 root uucp 248, 5 Oct 27 09:37 /dev/ttyO5

[root@calcium ~]# dmesg | grep ttyO
[ 0.000000] Kernel command line: console=ttyO0,115200n8 coherent_pool=1M root=/dev/mmcblk0p2 rw fixrtc rootwait
[ 2.609482] 44e09000.serial: ttyO0 at MMIO 0x44e09000 (irq = 88, base_baud = 3000000) is a OMAP UART0
[ 3.406258] console [ttyO0] enabled
[ 3.417434] 48022000.serial: ttyO1 at MMIO 0x48022000 (irq = 89, base_baud = 3000000) is a OMAP UART1
[ 3.434458] 48024000.serial: ttyO2 at MMIO 0x48024000 (irq = 90, base_baud = 3000000) is a OMAP UART2
[ 3.451377] 481a8000.serial: ttyO4 at MMIO 0x481a8000 (irq = 61, base_baud = 3000000) is a OMAP UART4
[ 3.468239] 481aa000.serial: ttyO5 at MMIO 0x481aa000 (irq = 62, base_baud = 3000000) is a OMAP UART5
[ 5.205546] systemd[1]: Expecting device dev-ttyO0.device...
')
My only hunch is that the pinmux may be incorrect though it looks like this is no longer configured via /sys/. Apparently this changed around 3.8. Is there any way of configuring/checking the pinmux settings at the command line? Anyone else using the UARTs on the BBW?

[mfs]

Ok, finally got this working. I had to load a device tree blob. Specifically to enable UART5 I added this to uEnv.txt:

$this->bbcode_second_pass_code('', 'fdtfile=am335x-bone-ttyO5.dtb')