BlackS

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

I usually fight a bit the default 80x25 serial terminal sizing (KDE konsole) via 'screen /dev/ttyUSB0 1500000', but tools like MidnightCommander can be used. Certainly all standard CLI stuff and copy-paste. So just some commands:

apt list --installed linux-u-boot-rock-5b*
dpkg -L linux-u-boot-rock-5b-edge
cat /usr/lib/u-boot/platform_install.sh
cat /dev/mtdblock0 > /tmp/spidump
strings /tmp/spidump | grep -i U-Boot