https://wiki.analog.com/university/tools/pluto/devs/booting

https://wiki.analog.com/university/tools/pluto/hacking/hardware 

https://wiki.analog.com/university/tools/pluto/users/customizing 

https://tbspace.de/plutosdrclockinput.html

https://www.rapidtables.com/convert/number/decimal-to-hex.html

fw_setenv adi_loadvals 'fdt addr ${fit_load_address} && fdt get value fdt_choosen /configurations/${fit_config}/ fdt && fdt get addr fdtaddr /images/${fdt_choosen} data && fdt addr ${fdtaddr}; if test ! -n ${ad936x_skip_ext_refclk}; then if test -n ${ad936x_custom_refclk}; then fdt set /clocks/clock@0 clock-frequency ${ad936x_custom_refclk}; elif test -n ${ad936x_ext_refclk}; then fdt set /clocks/clock@0 clock-frequency ${ad936x_ext_refclk}; fi; fi; if test -n ${model}; then fdt set / model ${model}; fi; if test -n ${attr_name} && test -n ${attr_val}; then fdt set /amba/spi@e0006000/ad9361-phy@0 ${attr_name} ${attr_val}; fi'

fw_setenv ad936x_custom_refclk "<25000000>"