tpou

I am currently attempting to compile a device tree overlay, in connection with an OPi Zero 2. But my questions here are of rather general nature (with regards to DT compiling), so I posted it here. ------- Goal: Creating a DT overlay to enable certain hardware currently not working on the board: wifi and HDMI output. Alternatively, compiling a "full" .dtb file for the board, replacing the one currently used during boot. For completeness: In the below I experimented starting from the Armbian_22.08.7_Orangepizero2_bullseye_edge_5.19.16.img.xz image, 406585908 bytes. uname -a: "Linux orangepizero2 5.19.16-sunxi64 #22.08.6 SMP Tue Oct 18 06:56:22 UTC 2022 aarch64 GNU/Linux" Boot-up (at times shaky), UART and USB (via type A socket) is working with this image. ------- I have tried to assemble a dts file, to be made into an overlay, from snippets seen at https://github.com/jernejsk/linux-1/commit/e7222b1f0dfde22a3b60de7f3add6599fd942e84 But this runs into errors, as references are missing, in this case for example "reg_aldo2". I can look at the complete file, https://github.com/jernejsk/linux-1/blob/e7222b1f0dfde22a3b60de7f3add6599fd942e84/arch/arm64/boot/dts/allwinner/sun50i-h616-orangepi-zero2.dts and see that it includes #include "sun50i-h616.dtsi", which I can copy from the tree. Further I can make additional code additions that all missing references are resolvable. Nevertheless, even then errors (or to be exact: warnings) remain that look as if the resulting .dtbo will not be functional. Thus: What is the typical workflow in compiling overlays? 1. How much of existing code needs to be included? (I also tried, as alternative to above, to decompile the existing dtb and use it as included file in my compilation - is this a reasonable avenue?) 2. What are negligible warnings? 3. If I compiled something resulting in an erroreous .dtbo, could it be harmful to the hardware? (Or asked differently: tinkering with what parts of the device tree is potentially damaging to the board?) ------- Example warnings: sun50i-h616.dtsi:109.6-1009.4: Warning (unit_address_vs_reg): /soc: node has a reg or ranges property, but no unit name also defined at orangepi-zero2_wifi_and_hdmi.dts:61.13-81.11 sun50i-h616.dtsi:375.21-395.5: Warning (avoid_unnecessary_addr_size): /soc/mmc@4021000: unnecessary #address-cells/#size-cells without "ranges" or child "reg" property also defined at orangepi-zero2_wifi_and_hdmi.dts:63.25-79.15 Thanks to the knowledgable.

@ALIGMSTEN Hello, you mentioned you had to "power cycle" [to make it successfully boot], near Aug 10, for this board. Can you write with which board version you are working with. (silk-screened in white on the board, something like v1.x, in same text body as the OrangePi logo)

@TheOWL: You said "2: I use the newest image , display nothing on screen. But i have an older version image. It display to screen by Micro-HDMI perfect." Which older version was it, on which HDMI output worked? (I observed non-working HDMI-output, or say exactly: nothing displayed on the monitor, as well for Armbian 22.08 bullseye.)