U-BOOT flashing for bare metal BeagleBone Black

Hi Robert,

I guess it may be not easy thing to do. The raw usb flash drive is instantiated ( as rootfs). The device /dev/[sdb] is for u-boot and /dev/[sdb1] is rootfs partition, I believe. But

  1. the BalenaEtcher only selects rootfs (currently). There is no option for
    /dev/sdb ?
  2. How to import image files [MLO and u-boot.img] into BalenaEtcher?
    Or is there a way to combine and convert image format for Etcher?

Best Regards,

David