[yocto] [meta-raspberrypi] Confusion about U-Boot setup

[Greg Wilson-Lindberg]

I've configured a sumo build, by way of QT's boot2qt to use u-boot and I am seeing a u-boot prompt for keypress to drop out of automatic booting on startup, but I don't see any configuration scripts for u-boot (uEnv.txt or a script) on the image or in the build tmp/ dir.

For the raspberry pi, how is u-boot configured on startup?

Regards,
Greg Wilson-Lindberg