Change the device tree

The modern tree, firmware-modern/dts/zynq-pluto-sdr-fishball.dts, is an overlay on ADI's zynq-pluto-sdr.dtsi: it states only where this board differs from an ADALM-Pluto.

firmware-modern/ (6.12)firmware/ (5.15)

# run from: firmware-modern/src/linux
CROSS=arm-linux-gnueabi-      # or arm-linux-gnueabihf-
make ARCH=arm CROSS_COMPILE=$CROSS DTC_FLAGS=-@ xilinx/zynq-pluto-sdr-fishball.dtb
# The rename is yours to do: tools/flash.sh looks for the literal name
# devicetree.dtb and aborts if it is missing.
cp arch/arm/boot/dts/xilinx/zynq-pluto-sdr-fishball.dtb ../../output/devicetree.dtb

# run from: the repo root
python3 firmware-modern/verify_dtb.py firmware-modern/output/devicetree.dtb   # stdlib only
./devkit flash --dtb-only

The factory tree is one flat file, arch/arm/boot/dts/zynq-pluto-sdr-fishball.dts.

# run from: firmware/
DTC_FLAGS=-@ make -C src/linux ARCH=arm \
  CROSS_COMPILE=arm-linux-gnueabi- zynq-pluto-sdr-fishball.dtb
cp src/linux/arch/arm/boot/dts/zynq-pluto-sdr-fishball.dtb output/devicetree.dtb

# run from: the repo root
./devkit flash --target factory --dtb-only

Check the built .dtb, not the .dts. Most of what lands in it comes from the dtsi, and two mistakes found here built and booted fine:

Mistake	Effect
a memory@0 node beside the dtsi's memory node	the kernel gets two memory sizes; dtc only warns "duplicate unit-address"
no adi,channels	the DMA driver fails to probe on this board's 2018-era FPGA cores, and nothing streams

verify_dtb.py runs 16 checks, including that every node the factory tree enables is still enabled; CI runs it on every push. Keep adi,tx-attenuation-mdB = 89750 in the AD9361 node: it is the safety setting that makes the transmitter come up at −89.75 dB.

The device tree must match the bitstream

Change what the FPGA contains and the description may need to change too.

More: the modern kernel.