How to disable console debug message on tty0

my system is jetpack 3.2.1 , How can I delete parameter " console = tty0 ",
I didn’t want my tty0 to print the debug message

nvidia@tegra-ubuntu:~$ cat /proc/cmdline 
root=/dev/mmcblk0p1 rw rootwait console=ttyS0,115200n8 console=tty0 OS=l4t fbcon=map:0 net.ifnames=0 memtype=0 video=tegrafb no_console_suspend=1 earlycon=uart8250,mmio32,0x03100000 nvdumper_reserved=0x2772e0000 gpt tegra_fbmem2=0x800000@0x969ee000 lut_mem2=0x2008@0x969eb000 tegraid=18.1.2.0.0 tegra_keep_boot_clocks maxcpus=6 boot.slot_suffix= boot.ratchetvalues=0.2.1 androidboot.serialno=0324617130285 bl_prof_dataptr=0x10000@0x277040000 sdhci_tegra.en_boot_part_access=1 root=/dev/mmcblk0p1 rw rootwait rootfstype=ext4

If you only care about Linux printing debug, and not stopping debug messages under U-Boot (which you can’t see on a monitor anyway), then look at “/boot/extlinux/extlinux.conf”. Remove the “console=tty0”. If that doesn’t work it might be inheriting from U-Boot (or the CBoot which U-Boot inherits from).

Hi linuxdev
Here is my /boot/extlinux/extlinux.conf , It dosn’t have the parameter “console=tty0”

LABEL primary
      MENU LABEL primary kernel
      LINUX /boot/Image
      APPEND ${cbootargs} root=/dev/mmcblk0p1 rw rootwait rootfstype=ext4

As you said ,It inheriting from CBoot , But I don’t know how to modify the " cbootargs " parameter

By modefing the file p2771-0000.conf.common in Linux_for_Tegra
deleting parameter “console=tty0” can solve my problem

fi;
ROOTFSSIZE=28GiB;
CMDLINE_ADD="console=ttyS0,115200n8 OS=l4t fbcon=map:0 net.ifnames=0";
target_board="t186ref";
ROOT_DEV="mmcblk0p12 ------------ internal eMMC.
        sda1 ----------------- external USB devices. (USB memory stick, HDD)
        eth0 ----------------- nfsroot via RJ45 Ethernet port.
        eth1 ----------------- nfsroot via USB Ethernet interface.";

but that have anather question,I find the ubuntu system startup log like "[OK] Listening on udev Kernel Socket."is disappeared on tty0 and was printed in ttySo series port

Welcome to e[1mUbuntu 16.04 LTSe[0m!

[    6.598050] systemd[1]: Set hostname to <tegra-ubuntu>.
[    6.710079] systemd[1]: Listening on udev Kernel Socket.
[e[0;32m  OK  e[0m] Listening on udev Kernel Socket.
[    6.724006] systemd[1]: Listening on Journal Audit Socket.
[e[0;32m  OK  e[0m] Listening on Journal Audit Socket.
[    6.736424] systemd[1]: Created slice User and Session Slice.
[e[0;32m  OK  e[0m] Created slice User and Session Slice.
[    6.751925] systemd[1]: Listening on udev Control Socket.
[e[0;32m  OK  e[0m] Listening on udev Control Socket.
[    6.763892] systemd[1]: Started Forward Password Requests to Wall Directory Watch.
[e[0;32m  OK  e[0m] Started Forward Password Requests to Wall Directory Watch.
[    6.779812] systemd[1]: Reached target Swap.
[e[0;32m  OK  e[0m] Reached target Swap.
[    6.791871] systemd[1]: Listening on Journal Socket (/dev/log).
[e[0;32m  OK  e[0m] Listening on Journal Socket (/dev/log).
[    6.807880] systemd[1]: Listening on Journal Socket.
[e[0;32m  OK  e[0m] Listening on Journal Socket.
[    6.819837] systemd[1]: Reached target Remote File Systems (Pre).
[e[0;32m  OK  e[0m] Reached target Remote File Systems (Pre).
[    6.835831] systemd[1]: Reached target Remote File Systems.
[e[0;32m  OK  e[0m] Reached target Remote File Systems.
[    6.848313] systemd[1]: Created slice System Slice.
[e[0;32m  OK  e[0m] Created slice System Slice.
[    6.861184] systemd[1]: Mounting POSIX Message Queue File System...
         Mounting POSIX Message Queue File System...
[    6.880760] systemd[1]: Starting Load Kernel Modules...
         Starting Load Kernel Modules...
[    6.893462] systemd[1]: Starting Create list of required static device nodes for the current kernel...
         Starting Create list of required st... nodes for the current kernel...
[    6.912457] systemd[1]: Created slice system-serial\x2dgetty.slice.
[e[0;32m  OK  e[0m] Created slice system-serial\x2dgetty.slice.
[    6.927865] systemd[1]: Reached target Slices.
[e[0;32m  OK  e[0m] Reached target Slices.
[    6.941118] systemd[1]: Started Braille Device Support.
[e[0;32m  OK  e[0m] Started Braille Device Support.
[    6.957720] systemd[1]: Starting Remount Root and Kernel File Systems...
         Starting Remount Root and Kernel File Systems..[    6.966488] EXT4-fs (mmcblk0p1): re-mounted. Opts: (null)
.
[    6.980403] systemd[1]: Created slice system-getty.slice.
[e[0;32m  OK  e[0m] Created slice system-getty.slice.
[    6.991861] systemd[1]: Reached target Encrypted Volumes.
[e[0;32m  OK  e[0m] Reached target Encrypted Volumes.
[    7.003922] systemd[1]: Listening on /dev/initctl Compatibility Named Pipe.
[e[0;32m  OK  e[0m] Listening on /dev/initctl Compatibility Named Pipe.
[    7.019924] systemd[1]: Started Trigger resolvconf update for networkd DNS.
[e[0;32m  OK  e[0m] Started Trigger resolvconf update for networkd DNS.
[    7.038779] systemd[1]: Mounting Debug File System...
         Mounting Debug File System...
[    7.051889] systemd[1]: Listening on Syslog Socket.
[e[0;32m  OK  e[0m] Listening on Syslog Socket.
[    7.065397] systemd[1]: Starting Journal Service...
         Starting Journal Service...
[    7.078380] systemd[1]: Mounted Debug File System.
[e[0;32m  OK  e[0m] Mounted Debug File System.
[    7.091893] systemd[1]: Mounted POSIX Message Queue File System.
[e[0;32m  OK  e[0m] Mounted POSIX Message Queue File System.
[    7.109024] systemd[1]: Started Load Kernel Modules.
[e[0;32m  OK  e[0m] Started Load Kernel Modules.
[    7.124883] systemd[1]: Started Create list of required static device nodes for the current kernel.
[e[0;32m  OK  e[0m] Started Create list of required sta...ce nodes for the current kernel.
[    7.146054] systemd[1]: Started Remount Root and Kernel File Systems.
[e[0;32m  OK  e[0m] Started Remount Root and Kernel File Systems.
[    7.160206] systemd[1]: Started Journal Service.
[e[0;32m  OK  e[0m] Started Journal Service.
         Starting udev Coldplug all Devices...
         Starting Load/Save Random Seed...
         Starting Flush Journal to Persistent Storage...
         Starting Create Static Device Nodes in /dev...
         Starting Apply Kernel Variables...
         Mounting Configuration File System...
[e[0;32m  OK  e[0m] Mounted Configuration File System.
[e[0;32m  OK  e[0m] Started Load/Save Random Seed.
[e[0;32m  OK  e[0m] Started Create Static Device Nodes in /dev.
[e[0;32m  OK  e[0m] Started Apply Kernel Variables.
[    7.333554] systemd-journald[298]: Received request to flush runtime journal from PID 1
[e[0;32m  OK  e[0m] Started Flush Journal to Persistent Storage.
         Starting udev Kernel Device Manager...
[e[0;32m  OK  e[0m] Reached target Local File Systems (Pre).
[e[0;32m  OK  e[0m] Started udev Kernel Device Manager.
[e[0;32m  OK  e[0m] Started udev Coldplug all Devices.
         Starting lvm2.service...
[e[0;32m  OK  e[0m] Started Dispatch Password Requests to Console Directory Watch.
[e[0;32m  OK  e[0m] Started lvm2.service.
[e[0;32m  OK  e[0m] Reached target Local File Systems.
         Starting Set console keymap...
         Starting LSB: AppArmor initialization...
         Starting Create Volatile Files and Directories...
         Starting Tell Plymouth To Write Out Runtime Data...
[    7.521837] tegra-pcie 10003000.pcie-controller: 4x1, 1x1 configuration
         Starting Clean up any mess left by 0dns-up...
[    7.541472] xhci-tegra 3530000.xhci: cannot find firmware....retry after 1 second
[    7.550102] tegra-pcie 10003000.pcie-controller: PCIE: Enable power rails
[    7.558372] tegra-pcie 10003000.pcie-controller: probing port 0, using 4 lanes
[e[0;32m  OK  e[0m] Started Tell Plymouth To Write Out Runti[    7.567964] tegra-pcie 10003000.pcie-controller: probing port 2, using 1 lanes
me Data.
[e[0;32m  OK  e[0m] Found device /dev/ttyS0.
[e[0;32m  OK  e[0m] Started Set console keymap.
[e[0;32m  OK  e[0m] Started Create Volatile Files and Directories.
[e[0;32m  OK  e[0m] Started Clean up any mess left by 0dns-up.
[e[0;32m  OK  e[0m] Started LSB: AppArmor initialization.
[    7.779427] dhd_module_init in
         Starting Nameserver information manager...
[    7.788446] tegra_net_perf_init: cannot get wifi sclk
         Starting Update UTMP about System Boot/Shutdown...
[    7.799876] found wifi platform device bcmdhd_wlan
[e[0;32m  OK  e[0m] Reached target Sound Card.
[    7.809438] wifi_platform_get_country_code_map: could not get country_code_map
[    7.818247] wifi_plat_dev_drv_probe:platform country code map is not available
[    7.825516] Power-up adapter 'DHD generic adapter'
[    7.830337] wifi_platform_set_power = 1
[e[0;32m  OK  e[0m] Started Nameserver information manager.
[e[0;32m  OK  e[0m] Started Update UTMP about System Boot/Shutdown.
[e[0;32m  OK  e[0m] Listening on Load/Save RF Kill Switch Status /dev/rfkill Watch.
[e[0;32m  OK  e[0m] Reached target System Initialization.
[e[0;32m  OK  e[0m] Listening on GPS (Global Positioning System) Daemon Sockets.
         Starting Socket activation for snappy daemon.
[e[0;32m  OK  e[0m] Listening on RPCbind Server Activation Socket.
         Starting Docker Socket for the API.
[    7.976897] cfg80211: World regulatory domain updated:
[    7.982050] cfg80211:  DFS Master region: unset
[    7.986419] cfg80211:   (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time)
[    7.986425] cfg80211:   (2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A, 2000 mBm), (N/A)
[    7.986427] cfg80211:   (2457000 KHz - 2482000 KHz @ 40000 KHz), (N/A, 2000 mBm), (N/A)
[    7.986429] cfg80211:   (2474000 KHz - 2494000 KHz @ 20000 KHz), (N/A, 2000 mBm), (N/A)
[    7.986431] cfg80211:   (5170000 KHz - 5250000 KHz @ 80000 KHz, 160000 KHz AUTO), (N/A, 2000 mBm), (N/A)
[    7.986433] cfg80211:   (5250000 KHz - 5330000 KHz @ 80000 KHz, 160000 KHz AUTO), (N/A, 2000 mBm), (0 s)
[    7.986435] cfg80211:   (5490000 KHz - 5730000 KHz @ 160000 KHz), (N/A, 2000 mBm), (0 s)
[    7.986437] cfg80211:   (5735000 KHz - 5835000 KHz @ 80000 KHz), (N/A, 2000 mBm), (N/A)
[    7.986438] cfg80211:   (57240000 KHz - 63720000 KHz @ 2160000 KHz), (N/A, 0 mBm), (N/A)
[    8.007816] tegra-pcie 10003000.pcie-controller: link 0 down, retrying
[    8.031768] wifi_platform_bus_enumerate device present 1
[    8.049502] wifi_platform_bus_enumerate device present 0
[    8.049846] F1 signature read @0x18000000=0x17214354
[    8.053338] F1 signature OK, socitype:0x1 chip:0x4354 rev:0x1 pkg:0x2
[    8.053830] DHD: dongle ram size is set to 786432(orig 786432) at 0x180000
[    8.053884] wifi_platform_prealloc: failed to alloc static mem section 7
[    8.053890] wifi_platform_get_mac_addr
[    8.055242] CFG80211-ERROR) wl_setup_wiphy : Registering Vendor80211
[    8.055457] wl_create_event_handler(): thread:wl_event_handler:228 started
[    8.055462] CFG80211-ERROR) wl_event_handler : tsk Enter, tsk = 0xffffffc1e3f21a70
[    8.055558] dhd_attach(): thread:dhd_watchdog_thread:229 started
[    8.055594] dhd_attach(): thread:dhd_dpc:22a started
[    8.055629] dhd_attach(): thread:dhd_rxf:22b started
[    8.055634] dhd_deferred_work_init: work queue initialized 
[    8.055821] Dongle Host Driver, version 1.201.82 (r)
[    8.055821] Compiled in drivers/net/wireless/bcmdhd on May 17 2018 at 00:12:47
[    8.056077] tegra_sysfs_register
[    8.056101] Register interface [wlan0]  MAC: 00:04:4b:8d:93:8d
[    8.056101] 
[    8.056103] dhd_prot_ioctl : bus is down. we have nothing to do
[    8.056180] sdhci-tegra 3440000.sdhci: Tuning already done, restoring the best tap value : 20
[    8.057218] wifi_platform_set_power = 0
[e[0;32m  OK  e[0m] Listening on CUPS Scheduler.
[e[0;32m  OK  e[0m] Listening on D-Bus System Message Bus Socket.
[e[0;32m  OK  e[0m] Started Daily apt activities.
[e[0;32m  OK  e[0m] Started Daily Cleanup of Temporary Directories.
[e[0;32m  OK  e[0m] Reached target Timers.
[e[0;32m  OK  e[0m] Started CUPS Scheduler.
[e[0;32m  OK  e[0m] Reached target Paths.
[e[0;32m  OK  e[0m] Listening on Avahi mDNS/DNS-SD Stack Activation Socket.
[e[0;32m  OK  e[0m] Reached target Network (Pre).
         Starting Raise network interfaces...
[e[0;32m  OK  e[0m] Listening on Socket activation for snappy daemon.
[e[0;32m  OK  e[0m] Listening on Docker Socket for the API.
         Starting Load/Save RF Kill Switch Status...
[e[0;32m  OK  e[0m] Reached target Sockets.
[e[0;32m  OK  e[0m] Reached target Basic System.
         Starting LSB: automatic crash report generation...
[e[0;32m  OK  e[0m] Started CUPS Scheduler.
         Starting Restore /etc/resolv.conf i...re the ppp link was shut down...
         Starting Modem Manager...
         Starting LSB: Speech Dispatcher...
         Starting System Logging Service...
[    8.411783] tegra-pcie 10003000.pcie-controller: link 0 down, retrying
         Starting Avahi mDNS/DNS-SD Stack...
[e[0;32m  OK  e[0m] Started GPS (Global Positioning System) Daemon.
[e[0;32m  OK  e[0m] Started Configure USB flashing port for device mode.
[e[0;32m  OK  e[0m] Started Run anacron jobs.
[e[0;32m  OK  e[0m] Started face capture server.
[    8.551412] using random self ethernet address
[    8.555913] using random host ethernet address
[    8.565537] xhci-tegra 3530000.xhci: Firmware timestamp: 2017-12-07 10:50:08 UTC, Version: 55.09 release
[    8.573733] Mass Storage Function, version: 2009/09/11
[    8.573737] LUN: removable file: (no medium)
[    8.577905] using random self ethernet address
[    8.577908] using random host ethernet address
[    8.582429] usb0: HOST MAC 6e:cd:3d:3a:cc:b3
[    8.582472] usb0: MAC 56:09:97:03:06:98
[    8.582761] usb1: HOST MAC 76:5a:77:03:4a:24
[    8.582772] usb1: MAC de:38:b7:3b:a3:17
[    8.582792] tegra-xudc-new 3550000.xudc: ep 0 (type: 0, dir: out) enabled
[e[0;32m  OK  e[0m] Started Regu[    8.618457] xhci-tegra 3530000.xhci: xHCI Host Controller
lar background program processin[    8.626618] xhci-tegra 3530000.xhci: new USB bus registered, assigned bus number 1
g daemon.
[    8.637766] xhci-tegra 3530000.xhci: hcc params 0x0184fd25 hci version 0x100 quirks 0x00010810
[    8.646458] xhci-tegra 3530000.xhci: irq 59, io mem 0x03530000
[    8.652439] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
[   8.659303] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[    8.666511] usb usb1: Product: xHCI Host Controller
         Starting NVIDIA specifi[    8.671506] usb usb1: Manufacturer: Linux 4.4.38-tegra xhci-hcd
c first-boot script...
[    8.680234] usb usb1: SerialNumber: 3530000.xhci
[    8.687144] hub 1-0:1.0: USB hub found
[    8.690992] hub 1-0:1.0: 4 ports detected
         Starting Save/Restore Sound Card State...
[e[0;32m  OK  e[0m] Started D-Bus System Message Bus.
[    8.710241] device usb0 entered promiscuous mode
[    8.715448] xhci-tegra 3530000.xhci: xHCI Host Controller
[    8.720934] xhci-tegra 3530000.xhci: new USB bus registered, assigned bus number 2
[    8.726485] IPv6: ADDRCONF(NETDEV_UP): usb0: link is not ready
[    8.730213] device usb1 entered promiscuous mode
[    8.734170] IPv6: ADDRCONF(NETDEV_UP): usb1: link is not ready
[    8.734175] l4tbr0: port 2(usb1) entered forwarding state
[    8.734187] l4tbr0: port 2(usb1) entered forwarding state
[    8.755860] usb usb2: New USB device found, idVendor=1d6b, idProduct=0003
[    8.762735] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[    8.770029] usb usb2: Product: xHCI Host Controller
[    8.774984] usb usb2: Manufacturer: Linux 4.4.38-tegra xhci-hcd
[    8.780971] usb usb2: SerialNumber: 3530000.xhci
[    8.786052] hub 2-0:1.0: USB hub found
[    8.789935] hub 2-0:1.0: 3 ports detected
[    8.794431] tegra-xotg xotg: otg: host 3530000.xhci registered
[    8.800389] android_work: did not send uevent (0 0           (null))
[    8.829829] tegra-pcie 10003000.pcie-controller: link 0 down, retrying
[    8.838398] tegra-pcie 10003000.pcie-controller: link 0 down, ignoring

How can I recover the ubuntu system startup log like “[OK] Listening on udev Kernel Socket.” to
the tty0 ?

It is correct that cbootargs is inherited via the device tree and ends up in U-Boot, then is passed on to the Linux kernel through that environment variable. So removing the “console=tty0” from the device tree should do the job.

However, I am a bit confused about the question to “recover the ubuntu system startup log”…were you not intending to disable this?

Hi linuxdev
when I remove “console=tty0”,I couldn’t see anaything on the tty0,
I hope I can see the systemd startup log like this

Welcome to Fedora 20 (Heisenbug)!

[  OK  ] Reached target Remote File Systems.
[  OK  ] Listening on Delayed Shutdown Socket.
[  OK  ] Listening on /dev/initctl Compatibility Named Pipe.
[  OK  ] Reached target Paths.
[  OK  ] Reached target Encrypted Volumes.
[  OK  ] Listening on Journal Socket.
         Mounting Huge Pages File System...
         Mounting POSIX Message Queue File System...
         Mounting Debug File System...
         Starting Journal Service...
[  OK  ] Started Journal Service.
         Mounting Configuration File System...
         Mounting FUSE Control File System...
[  OK  ] Created slice Root Slice.
[  OK  ] Created slice User and Session Slice.
[  OK  ] Created slice System Slice.
[  OK  ] Reached target Slices.
[  OK  ] Reached target Swap.
         Mounting Temporary Directory...
[  OK  ] Reached target Local File Systems (Pre).
         Starting Load Random Seed...
         Starting Load/Save Random Seed...
[  OK  ] Mounted Huge Pages File System.
[  OK  ] Mounted POSIX Message Queue File System.
[  OK  ] Mounted Debug File System.
[  OK  ] Mounted Configuration File System.
[  OK  ] Mounted FUSE Control File System.
[  OK  ] Mounted Temporary Directory.
[  OK  ] Started Load Random Seed.
[  OK  ] Started Load/Save Random Seed.
[  OK  ] Reached target Local File Systems.
         Starting Recreate Volatile Files and Directories...
         Starting Trigger Flushing of Journal to Persistent Storage...
[  OK  ] Started Recreate Volatile Files and Directories.
         Starting Update UTMP about System Reboot/Shutdown...
[  OK  ] Started Trigger Flushing of Journal to Persistent Storage.
[  OK  ] Started Update UTMP about System Reboot/Shutdown.
[  OK  ] Reached target System Initialization.
[  OK  ] Reached target Timers.
[  OK  ] Listening on D-Bus System Message Bus Socket.
[  OK  ] Reached target Sockets.
[  OK  ] Reached target Basic System.
         Starting Permit User Sessions...
         Starting D-Bus System Message Bus...
[  OK  ] Started D-Bus System Message Bus.
         Starting Login Service...
         Starting Cleanup of Temporary Directories...
[  OK  ] Started Permit User Sessions.
[  OK  ] Started Cleanup of Temporary Directories.
         Starting Console Getty...
[  OK  ] Started Console Getty.
[  OK  ] Reached target Login Prompts.
[  OK  ] Started Login Service.
[  OK  ] Reached target Multi-User System.

You said you don’t want tty0 to print debug messages. This is what removing that console=tty0 does. Are you talking about needing to remove serial console and not regular console? Or perhaps removing a specific debug message? What you see as missing is exactly what removing tty0 as a console debug is for.

Btw, normal boot puts debug on tty0, and upon reaching graphical user login tty0 is replaced with the GUI. tty1-tty5 are still available for consoles, but this is normal that tty0 goes away and becomes a GUI.