The drm_prime error is somehow "normal": AFAIR mpv was trying each hardware decoder in turn and, if it does not support the codec, prints the error and tries the next hardware decoder in line. If you try to decode h.265, perhaps it first picks an hardware decoder which does not support such codec with such parameters and prints the error, then tries another decoder which is capable and everything works. Usually rockchip devices have two hardware decoders, Hantro and rkvdec; Hantro does not support h.265 at all on older chips, but rkvdec does.

@ArturHey you did a lot of experimentation, but actually I think you are stuck on something different. GPT partition error message is something you can totally ignore, either because stock firmware usually don't provide a GPT partition, and armbian images neither do. The rockchip miniloader supports GPT partition table, but it is not mandatory to work. If there's a GPT partition, the miniloader searches for "uboot" and "trust" partitions to use them as hints for the base addresses. If there's no GPT partition, it will just use default base addresses and look for the LOADER and TRUST signatures. Anyway, armbian does not use anything from that: there is no rockchip miniloader, neither are GPT partitions or other proprietary code, except for the Trust OS, which is embedded into u-boot. The boot process is totally different on armbian. Now, the issue you have with flash not being recognized by rkdeveloptool makes me think about three possibile situations: a bug in rkdeveloptool you are still in maskrom mode and did not upload the usbplug firmware with rkdeveloptool db (ie: the board is not yet initialized) a broken flash in the eMCP part You can, for example, refer to the procedure Installation (without SD card, board with eMMC) described in the first post of this thread if you want to write a raw image in the flash memory but I always suggest to erase the flash memory and test the image via sdcard first, rather than installing the image immediately, because you can softbrick the board. About the non-booting multitool, you should post some logs from the serial uart, but probably the main issue is related to the trust os which freezes the board after few seconds.

I now found a workaround, basically adding the following to the top of /boot/boot.cmd setenv usbstoragequirks "0x2537:0x1066:u,0x2537:0x1068:u" and running mkimage -C none -A arm -T script -d /boot/boot.cmd /boot/boot.scr (as shown at the bottom of /boot/boot.cmd However this is not sustainable, and it would still be preferable if the inclusion of armbianEnv.txt could be fixed, ESPECIALLY considering that the download page https://www.armbian.com/odroid-n2/ gives the following (useless due to this issue) advise: On modern kernels adding “video=HDMI-A-1:1920x1080M@60D” to boot /boot/armbianEnv.txt (extraargs=) should force HDMI to 1080p instead of the 4K native resolution.

Probably because nobody had use for those until today. Feel free to send a PR adding whats missing.

https://www.armbian.com/download/ https://github.com/armbian/os/releases https://github.com/armbian/community/releases