Well, that's strange, and thus I am a bit confused. I retried a few times: flashed Armbian_25.8.1_Rpi4b_noble_current_6.12.41_xfce_desktop.img.xz onto a micro-SD card in a UGREEN SD-card reader. I tried both rpi-imager and plain old dd. I am using a WCH340-based USB-serial adapter (came from the Pine64 webshop) wired up apparently correctly (see the attached photo). (I believe that my initial problem may have been caused by the rpi-imager custiomization settings, that I thought were supported with the Armbian image too.) Since then I stopped using those customization settings. The system now boots OK, the GUI comes up, but I'm still not seeing anything in the minicom screen. My config.txt settings are still: usb_max_current_enable=1 enable_uart=1 dtoverlay=uart0 dtparam=pciex1 dtparam=pciex1_gen=3 max_current_enable=1 dtoverlay=disable-wifi dtoverlay=disable-bt I now have both ttyAMA0 and ttyAMA10 devices: root@rpi5b:~# ls -l /dev/ttyAMA* crw-rw---- 1 root dialout 204, 64 nov 7 12:16 /dev/ttyAMA0 crw--w---- 1 root tty 204, 74 nov 7 12:57 /dev/ttyAMA10 root@rpi5b:~# systemctl status serial-getty@ttyAMA10.service ● serial-getty@ttyAMA10.service - Serial Getty on ttyAMA10 Loaded: loaded (/usr/lib/systemd/system/serial-getty@.service; enabled-runtime; preset: enabled) Drop-In: /usr/lib/systemd/system/serial-getty@.service.d └─10-term.conf Active: active (running) since Fri 2025-11-07 12:57:12 CET; 1h 49min ago Docs: man:agetty(8) man:systemd-getty-generator(8) https://0pointer.de/blog/projects/serial-console.html Main PID: 2714 (agetty) Tasks: 1 (limit: 9411) Memory: 200.0K (peak: 1.7M) CPU: 12ms CGroup: /system.slice/system-serial\x2dgetty.slice/serial-getty@ttyAMA10.service └─2714 /sbin/agetty -o "-p -- \\u" --keep-baud 115200,57600,38400,9600 - linux nov 07 12:57:12 rpi5b systemd[1]: serial-getty@ttyAMA10.service: Scheduled restart job, restart counter is at 1. nov 07 12:57:12 rpi5b systemd[1]: Started serial-getty@ttyAMA10.service - Serial Getty on ttyAMA10. root@rpi5b:/usr/lib/systemd/system# systemctl enable --now serial-getty@ttyAMA0 Created symlink /etc/systemd/system/getty.target.wants/serial-getty@ttyAMA0.service → /usr/lib/systemd/system/serial-getty@.service. root@rpi5b:/usr/lib/systemd/system# systemctl restart serial-getty@ttyAMA0 root@rpi5b:/usr/lib/systemd/system# fuser -c /dev/ttyAMA0 /dev/ttyAMA0: 42rc 3040m 4999 root@rpi5b:/usr/lib/systemd/system# ps auxfw | fgrep 4999 root 5013 0.0 0.0 9040 2108 pts/4 S+ 14:50 0:00 \_ grep -F --color=auto 4999 root 4999 0.0 0.0 8192 1956 ttyAMA0 Ss+ 14:49 0:00 /sbin/agetty -o -p -- \u --keep-baud 115200,57600,38400,9600 - linux root@rpi5b:/usr/lib/systemd/system# systemctl restart serial-getty@ttyAMA10 root@rpi5b:/usr/lib/systemd/system# And in the end, nothing seems to be happening when I start the new getty on AMA0 or restart the old one on AMA10. I am puzzled.

Armbian Trixie XFCE (Edge kernel 6.18.0-rc3-edge-rockchip64) + Stable mesa 25.0.7-2 + box64-rk3588 0.3.9+20251106.dcd3ba0-1 (https://ryanfortner.github.io/box64-debs/) + wine-10.18-staging-tkg-amd64-wow64 (https://github.com/Kron4ek/Wine-Builds/releases) + dxvk-sarek v1.11.0-sarek-async-writeaccessfix-malifix-5d21d2b (https://github.com/pythonlover02/DXVK-Sarek/actions) Elin ~40fps@720p

Hip hip hooray !!! Yep, this way worked. Will provide the all steps for people who have the same issue. $ apt install linux-u-boot-rock-5b-edge $ armbian-install # Just in case I've installed to the all partitions. I mean to 5th and 7th. > 5 Install/Update the bootloader on SD card (/dev/mmcblk1) > 7 Install/Update the bootloader on MTD Flash $ reboot And now I can enter to uboot shell change to F2: 1068MHz ch0 ttot12 ch1 ttot12 ch2 ttot12 ch3 ttot12 change to F3: 1560MHz ch0 ttot14 ch1 ttot14 ch2 ttot14 ch3 ttot14 change to F0: 2112MHz ch0 ttot16 ch1 ttot16 ch2 ttot16 ch3 ttot16 out U-Boot SPL 2024.04-armbian-2024.04-S830c-P0000-Hd72c-Vdfa5-Bb703-R448a (Oct 24 2025 - 02:33:30 +0000) Trying to boot from SPI ## Checking hash(es) for config config-1 ... OK ## Checking hash(es) for Image atf-1 ... sha256+ OK ## Checking hash(es) for Image u-boot ... sha256+ OK ## Checking hash(es) for Image fdt-1 ... sha256+ OK ## Checking hash(es) for Image atf-2 ... sha256+ OK ## Checking hash(es) for Image atf-3 ... sha256+ OK INFO: Preloader serial: 2 NOTICE: BL31: v2.3():v2.3-868-g040d2de11:derrick.huang, fwver: v1.48 NOTICE: BL31: Built : 15:02:44, Dec 19 2024 INFO: spec: 0x1 INFO: code: 0x88 INFO: ext 32k is not valid INFO: ddr: stride-en 4CH INFO: GICv3 without legacy support detected. INFO: ARM GICv3 driver initialized in EL3 INFO: valid_cpu_msk=0xff bcore0_rst = 0x0, bcore1_rst = 0x0 INFO: l3 cache partition cfg-0 INFO: system boots from cpu-hwid-0 INFO: disable memory repair INFO: idle_st=0x21fff, pd_st=0x11fff9, repair_st=0xfff70001 INFO: dfs DDR fsp_params[0].freq_mhz= 2112MHz INFO: dfs DDR fsp_params[1].freq_mhz= 528MHz INFO: dfs DDR fsp_params[2].freq_mhz= 1068MHz INFO: dfs DDR fsp_params[3].freq_mhz= 1560MHz INFO: BL31: Initialising Exception Handling Framework INFO: BL31: Initializing runtime services WARNING: No OPTEE provided by BL2 boot loader, Booting device without OPTEE initialization. SMC`s destined for OPTEE will return SMC_UNK ERROR: Error initializing runtime service opteed_fast INFO: BL31: Preparing for EL3 exit to normal world INFO: Entry point address = 0xa00000 INFO: SPSR = 0x3c9 ns16550_serial serial@feb50000: pinctrl_select_state_full: uclass_get_device_by_phandle_id: err=-19 U-Boot 2024.04-armbian-2024.04-S830c-P0000-Hd72c-Vdfa5-Bb703-R448a (Oct 24 2025 - 02:33:30 +0000) Model: Radxa ROCK 5 Model B DRAM: 16 GiB Core: 353 devices, 32 uclasses, devicetree: separate MMC: mmc@fe2c0000: 1, mmc@fe2d0000: 2, mmc@fe2e0000: 0 Loading Environment from SPIFlash... SF: Detected xt25f128 with page size 256 Bytes, erase size 4 KiB, total 16 MiB *** Warning - bad CRC, using default environment In: serial@feb50000 Out: serial@feb50000 Err: serial@feb50000 Model: Radxa ROCK 5 Model B rockchip_dnl_key_pressed: no saradc device found Net: No ethernet found. Hit any key to stop autoboot: 0 => Great Thanks a lot

What is easiest depends on the situation. If you feel comfortable enough to use dd to write bootloader, I just downloaded the -edge package from the beta apt package pool, extracted the .bin file and wrote it to correct location on SD-card, after saving the first 32k sectors also with dd to a backupfile. Then reboot and you know it. The qemu experiment was to boot directly from U-Boot to Btrfs raid1 filesystem, it took a lot of time browing through U-Boot config/compile options. Better/formal method is to install -edge package, it will remove -current package, then use armbian-config to write the bootloader explicitly.

Welcome to TV-Box section, that's the real size of your RAM: 4gb https://github.com/hqnicolas/Rockchip-Library/tree/main/RK356x/rkbin