Thanks @Portisch @bumerc. I finally could write u-boot into eMMC Minix U9-H with succes!!! and it is working perfectly! i can wake up minix with HDMI CEC and now in suspend mode all other HDMI CEC Devices are visible for TV!!
Great work!
I followed @Portisch guide in wiki (but modifiing one Command, (to delete actual u-boot this is the command * delete currently used u-boot: dd if=/dev/zero of=/dev/bootloader ) After delete u-boot, with a sd-card inserten, i rebooted the device with this command reboot update. I could boot into sdcard mode and write again u-boot into emmc following wiki guide!
Thanks again!