Kernel hangs when booting on BeagleBoard xM

Built the kernel according to https://eewiki.net/display/linuxonarm/BeagleBoard with v4.9.x-rt (Longterm 4.9.x + Real-Time Linux) and Root File System (small flash). It gets to Waiting for root device /dev/mmcblk0p2… and hangs there.

Any suggestions?

Thanks!
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