Continuing ... root@rockpi-4cplus:~# cp /boot/dtb/rockchip/rk3399-rock-4c-plus.dtb rk3399-rock-4c-plus.dtb.backup root@rockpi-4cplus:~# dtc -I dtb -O dts -o rk3399-rock-4c-plus.dts rk3399-rock-4c-plus.dtb.backup rk3399-rock-4c-plus.dts: Warning (unit_address_vs_reg): /usb@fe800000: node has a unit name, but no reg or ranges property rk3399-rock-4c-plus.dts: Warning (unit_address_vs_reg): /usb@fe900000: node has a unit name, but no reg or ranges property rk3399-rock-4c-plus.dts: Warning (avoid_unnecessary_addr_size): /dsi@ff960000: unnecessary #address-cells/#size-cells without "ranges", "dma-ranges" or child "reg" property rk3399-rock-4c-plus.dts: Warning (avoid_unnecessary_addr_size): /dsi@ff968000: unnecessary #address-cells/#size-cells without "ranges", "dma-ranges" or child "reg" property rk3399-rock-4c-plus.dts: Warning (unique_unit_address): /pcie@f8000000: duplicate unit-address (also used in node /pcie-ep@f8000000) root@rockpi-4cplus:~# root@rockpi-4cplus:~# vi rk3399-rock-4c-plus.dts rk3399-rock-4c-plus.dts is attached. Here is the relevant sections I've found: / { model = "Radxa ROCK 4C+"; aliases { serial2 = "/serial@ff1a0000"; }; serial@ff1a0000 { compatible = "rockchip,rk3399-uart\0snps,dw-apb-uart"; reg = <0x00 0xff1a0000 0x00 0x100>; clocks = <0x08 0x53 0x08 0x162>; clock-names = "baudclk\0apb_pclk"; interrupts = <0x00 0x64 0x04 0x00>; reg-shift = <0x02>; reg-io-width = <0x04>; pinctrl-names = "default"; pinctrl-0 = <0x49>; status = "okay"; phandle = <0xe7>; }; __symbols__ { uart2 = "/serial@ff1a0000"; }; }; What should I do to disable /dev/ttyS2 console? rk3399-rock-4c-plus.dts

@SteeMan srry for not posting more info lol last night i was gassed out, i spent all day digging into that issue. Apparently its working now, i had to add a pull-up resistor to the RX line, somehow now having it was causing issues while booting. I soldered male pin headers to the board, maybe those were acting as some kind of "antenna" causing the garbage input on the RX line, thats why when its propperly grounded and connected to a device like the ESP32 was booting fine. Not sure about the forum etiquette but i'll update my first post with everything i did in case someone has the same issue.... but i doubt anyone is as dumb as me hehe. For now, i was able to make it so it boots from EMMC or SD if present. I still have to try and see what happens if there is an SD without any boot info, not sure if it will try to boot and fail. I lack the propper knowledge on uBoot to see if all my enviorment variables are ok or i messed up any while messing with it. I should be home in about 2 hours so, i'll grab as much info as i can and post it here just in case

Thanks @SteeMan Made me stumble upon something similar. Found armbianmonitor rock@rockpi-4cplus:~$ sudo armbianmonitor -u Checked the log. [ 2.614818] ff180000.serial: ttyS0 at MMIO 0xff180000 (irq = 35, base_baud = 1500000) is a 16550A [ 2.616480] ff1a0000.serial: ttyS2 at MMIO 0xff1a0000 (irq = 36, base_baud = 1500000) is a 16550A Changed armbianEnv.txt from: console=both To: console=ttyS0 Then a reboot. That didn't work. So changing the boot.cmd from: setenv console "both" To: setenv console "ttyS0" Then mkimage -C none -A arm -T script -d /boot/boot.cmd /boot/boot.scr and reboot. ttyS2 console are still enabled. Connections are verified by reading the connected pins after forcing communication root@rockpi-4cplus:/home/rock# stty -F /dev/ttyS2 115200 cs8 -parenb -cstopb root@rockpi-4cplus:/home/rock# while true; do echo -n "A" > /dev/ttyS2; sleep 0.25; done Connected pins 8 & 10: And log still says: [ 2.615671] ff180000.serial: ttyS0 at MMIO 0xff180000 (irq = 35, base_baud = 1500000) is a 16550A [ 2.616076] serial serial0: tty port ttyS0 registered [ 2.617411] ff1a0000.serial: ttyS2 at MMIO 0xff1a0000 (irq = 36, base_baud = 1500000) is a 16550A [ 2.617621] printk: legacy console [ttyS2] enabled What would be the next step here?

moved to correct forum and added the proper tag

ok it's working I make a diff between pine64 and pine64+ root@domotique:~# diff pine64.txt pine64+.txt 5c5 < model = "Pine64"; --- > model = "Pine64+"; 9c9 < compatible = "pine64,pine64\0allwinner,sun50i-a64"; --- > compatible = "pine64,pine64-plus\0allwinner,sun50i-a64"; 202c202 < phandle = <0x40>; --- > phandle = <0x7b>; 261c261 < phandle = <0x7b>; --- > phandle = <0x40>; 282c282 < phandle = <0xb2>; --- > phandle = <0x37>; 303,308d302 < uart2-rts-cts-pins { < function = "uart2"; < pins = "PB2\0PB3"; < phandle = <0xb3>; < }; < 1102a1097 > regulator-enable-ramp-delay = <0x186a0>; 1365c1360 < pinctrl-0 = <0xb2>; --- > pinctrl-0 = <0x37>; 1371c1366 < status = "okay"; --- > status = "disabled"; 1848d1842 < uart2_rts_cts_pins = "/soc/pinctrl@1c20800/uart2-rts-cts-pins"; I think we just need to add uart2-rts-cts-pins { function = "uart2"; pins = "PB2\0PB3"; phandle = <0xb3>; }; uart2_rts_cts_pins = "/soc/pinctrl@1c20800/uart2-rts-cts-pins"; @Werner do you think it's possible to add this to the uart2 overlay ? cordially