wittrup Posted March 3 Posted March 3 Hello I want to disable console on /dev/ttyS2 on a Radxa ROCK 4C+ running rock@rockpi-4cplus:/boot$ cat /etc/os-release | grep -v URL PRETTY_NAME="Armbian 25.5.0-trunk.40 noble" NAME="Ubuntu" VERSION_ID="24.04" VERSION="24.04 LTS (Noble Numbat)" VERSION_CODENAME=noble ID=ubuntu ID_LIKE=debian UBUNTU_CODENAME=noble LOGO="armbian-logo" ARMBIAN_PRETTY_NAME="Armbian 25.5.0-trunk.40 noble" There are posts and other information out there. For instance: https://docs.armbian.com/User-Guide_Fine-Tuning/#how-to-toggle-boot-output which leads to http://redsymbol.net/linux-kernel-boot-parameters/ rock@rockpi-4cplus:/boot$ grep console armbianEnv.txt console=both The information found so far, implies there are options like: none, serial, both, and another But what is the another option? So that I can disable console on /dev/ttyS2 and use that for other purposes. Without compromising the Docs reccomandation: To disable console entirely (not recommended) set console to none 0 Quote
wittrup Posted March 3 Author Posted March 3 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? 0 Quote
wittrup Posted March 3 Author Posted March 3 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 0 Quote
IBV Posted March 4 Posted March 4 Hi, in general you can set status = "disabled"; in a dts to disable a component. 0 Quote
wittrup Posted March 4 Author Posted March 4 Thanks. Would this disable the ttyS2 entirely, or disable the console on ttyS2? 0 Quote
IBV Posted March 4 Posted March 4 This would disable it entirely, which is probably not what you want... It looks like the the the kernel is not picking up the console parameter: Kernel command line: root=UUID=d0636019-ca11-404a-9874-04e6cbfedf37 rootwait rootfstype=ext4 splash plymouth.ignore-serial-consoles console=ttyS2,1500000 console=tty1 consoleblank=0 loglevel=1 ubootpart=8dc56fe2-01 usb-storage.quirks=0x2537:0x1066:u,0x2537:0x1068:u cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory [ 0.000000] Unknown kernel command line parameters "splash ubootpart=8dc56fe2-01 cgroup_enable=memory cgroup_memory=1", will be passed to user space. Maybe post here the boot.cmd and armbianEnv.txt 0 Quote
wittrup Posted March 4 Author Posted March 4 Well spotted, thanks armbianEnv.txt verbosity=1 bootlogo=true console=ttyS0 overlay_prefix=rockchip rootdev=UUID=d0636019-ca11-404a-9874-04e6cbfedf37 rootfstype=ext4 usbstoragequirks=0x2537:0x1066:u,0x2537:0x1068:u boot.cmd (complete file attached): rock@rockpi-4cplus:~$ grep -i console /boot/boot.cmd setenv console "ttyS0" if test "${console}" = "display" || test "${console}" = "both"; then setenv consoleargs "console=tty1"; fi if test "${console}" = "serial" || test "${console}" = "both"; then setenv consoleargs "console=ttyS2,1500000 ${consoleargs}"; fi if test "${earlycon}" = "on"; then setenv consoleargs "earlycon ${consoleargs}"; fi setenv consoleargs "splash plymouth.ignore-serial-consoles ${consoleargs}" setenv consoleargs "splash=verbose ${consoleargs}" setenv bootargs "root=${rootdev} rootwait rootfstype=${rootfstype} ${consoleargs} consoleblank=0 loglevel=${verbosity} ubootpart=${partuuid} usb-storage.quirks=${usbstoragequirks} ${extraargs} ${extraboardargs}" boot.cmd 0 Quote
IBV Posted March 4 Posted March 4 It looks like if you set console="display" in armbianEnv.txt then the console kernel param will be set to tty1. This might resolve your problem. 0 Quote
wittrup Posted March 4 Author Posted March 4 Thanks Marked as solution. To answer my question wider; The console option, that are not specified in Armbian Documentation are: display All four options listed below: console=both console=serial console=display console=none To disable console entirely (not recommended) set console to none. 0 Quote
wittrup Posted March 8 Author Posted March 8 Forgive me. I apparently don't test thoroughly enough. Now: rock@rockpi-4cplus:~$ cat /boot/armbianEnv.txt verbosity=1 bootlogo=true console=display overlay_prefix=rockchip rootdev=UUID=d0636019-ca11-404a-9874-04e6cbfedf37 rootfstype=ext4 usbstoragequirks=0x2537:0x1066:u,0x2537:0x1068:u rock@rockpi-4cplus:~$ sudo mkimage -C none -A arm -T script -d /boot/boot.cmd /boot/boot.scr Image Name: Created: Sat Mar 8 18:21:32 2025 Image Type: ARM Linux Script (uncompressed) Data Size: 3843 Bytes = 3.75 KiB = 0.00 MiB Load Address: 00000000 Entry Point: 00000000 Contents: Image 0: 3835 Bytes = 3.75 KiB = 0.00 MiB rock@rockpi-4cplus:~$ sudo reboot Broadcast message from root@rockpi-4cplus on pts/1 (Sat 2025-03-08 18:22:02 UTC): The system will reboot now! rock@rockpi-4cplus:~$ Remote side unexpectedly closed network connection Even so, I can see my communication with Waveshare SIM7020E NB-IoT HAT are interrupted by console login request. How do I fulfill the disable ttyS2 console? rock@rockpi-4cplus:~$ sudo picocom /dev/ttyS2 picocom v3.1 Terminal ready *** local echo: yes *** *** baud: 115200 *** baud: 115200 *** AT AT OK rockpi-4cplus login: 0 Quote
Igor Posted March 8 Posted March 8 28 minutes ago, wittrup said: How do I fulfill the disable ttyS2 console? Check if getty is running on ttyS2 and stop it: sudo systemctl stop getty@ttyS2 0 Quote
wittrup Posted March 8 Author Posted March 8 Thanks rock@rockpi-4cplus:~$ picocom /dev/ttyS2 --baud 115200 --echo picocom v3.1 Terminal ready AT AT OK ockpi-4cplus login: ERROR Terminating... Thanks for using picocom rock@rockpi-4cplus:~$ sudo systemctl status getty@ttyS2 ○ getty@ttyS2.service - Getty on ttyS2 Loaded: loaded (/usr/lib/systemd/system/getty@.service; disabled; preset: enabled) Active: inactive (dead) Docs: man:agetty(8) man:systemd-getty-generator(8) https://0pointer.de/blog/projects/serial-console.html For reasons I cannot explain, I see getty@ttyS2 inactive at systemctl. Still it interrupts the UART. Also tried this: rock@rockpi-4cplus:~$ sudo systemctl status getty@ttyS2 [sudo] password for rock: ○ getty@ttyS2.service - Getty on ttyS2 Loaded: loaded (/usr/lib/systemd/system/getty@.service; disabled; preset: enabled) Active: inactive (dead) Docs: man:agetty(8) man:systemd-getty-generator(8) https://0pointer.de/blog/projects/serial-console.html rock@rockpi-4cplus:~$ sudo systemctl stop getty@ttyS2 rock@rockpi-4cplus:~$ sudo systemctl disable getty@ttyS2 rock@rockpi-4cplus:~$ sudo systemctl status getty@ttyS2 ○ getty@ttyS2.service - Getty on ttyS2 Loaded: loaded (/usr/lib/systemd/system/getty@.service; disabled; preset: enabled) Active: inactive (dead) Docs: man:agetty(8) man:systemd-getty-generator(8) https://0pointer.de/blog/projects/serial-console.html 0 Quote
Solution IBV Posted March 9 Solution Posted March 9 Hi, check the status of serial-getty@ttyS2.service and disable it. systemctl status serial-getty@ttyS2.service systemctl disable serial-getty@ttyS2.service Also can you please post your kernel command line again to check the console= param: cat /proc/cmdline According to the doc (https://0pointer.de/blog/projects/serial-console.html) systemd will spawn a serial getty for the console specified in the kernel command line. 1 Quote
wittrup Posted March 9 Author Posted March 9 Summary: /boot/armbianEnv.txt console=display systemctl disable getty@ttyS2 Maybe not necessary ... ? systemctl disable serial-getty@ttyS2.service Thanks everyone 0 Quote
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