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Starting from the Dunfell release of Linux Yocto, SECO Northern Europe devices no longer support a dynamic change of device configuration (e.g. display or touch settings) via xml file with the xconfig script. Initial device configurations need to be made before OS installation and will be attached permanently to that installation. Further changes down the line require a new installation of the OS.

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The process of booting into the Flash-N-Go System is described in the chapter [Deploying the Linux system to the target]. Within Flash-N-Go System, the xconfig script can be called to modify the device configuration.

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title	Working with xconfig

Calling xconfig to show available option:

Code Block
FLASH-N-GO:/# xconfig

List the installed configuration of the device:

Code Block
FLASH-N-GO:/# xconfig list

Delete the existing display config:

Code Block
FLASH-N-GO:/# xconfig delnode -y -p /variables/display

Import an xml configuration file, in this example a display config located in /mnt/mstick1/:

Code Block
FLASH-N-GO:/# xconfig import /mnt/mstick1/<my-display-config>.xml -y

More detail about Flash-N-Go infrastructure can be found here.

SECO Northern Europe system configuration

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As with xconfig, sconfig also no longer support dynamic changes of configuration in the target OS. A new OS installation is required for the new setting to take effect.

Some parts of the system configuration are stored in an xml file stored on one of the boot partitions of the eMMC. This information is shared between the backup OS Flash-N-Go System and the main OS, but also persistent between normal OS installations.

The shared information is stored in an xml file called config.xml, found in /etc/shared. For this purpose, there is a link to the script at /usr/sbin/sconfig which can be called without the absolute path:

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Call without parameter to show the list of current configurations on the system. Call with -h to show additional help.

If the script is called with a setting as parameter, the setting is read from the XML configuration and displayed on the console.

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Code Block
root@santaro:~# sconfig gateway 192.168.1.10 root@santaro:~# sconfig gateway 192.168.1.10

The ’name’ set with sconfig is also used as hostname for the device. It defaults to GFMM<serial number>.

Network configuration

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The Network Manager service is responsible for initializing all network interfaces at system startup and when an ethernet cable or a WLAN stick is plugged in.
The Network Manager stores its config files in the /etc/NetworkManager directory. Normally there is no need to change those files directly as there are some tools available to configure the network.

More information about Network Manager can be found here.

WLAN

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While SANTOKA has a built-in WLAN module, all other SECO Northern Europe products support WLAN using WLAN USB dongles. A list of supported devices can be found in the BSP release notes. WLAN can be used as client or provide an own network as Access Point.

Network management is done through nmcli, which is a command-line client for the Network Manager and reporting network status. A detail explanation of nmcli usage can be found here and here.

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title	Connect to a network

Scan for nearby networks:

Code Block
nmcli dev wifi list

Note the name of networks listed under the column SSID, to connect a desired network:

Code Block
nmcli dev wifi connect <network-name> password <network-password>

Once successfully connected, test the connection with ping:

Code Block
ping north.seco.com

Network Manager will save the connection and auto-connect on reboot, so you don't have to worry about issuing the command every time the device is booted.

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Expand

title	WLAN access point with sub net

To setup a WLAN Access point with own sub network including a DHCP service using the Network Manager use following commands:

Code Block

nmcli connection down wlan0-sconfig-autogenerated
nmcli con add type wifi ifname wlan0 con-name Hotspot autoconnect no ssid test
nmcli con modify Hotspot 802-11-wireless.mode ap 802-11-wireless.band bg ipv4.method shared wifi-sec.key-mgmt wpa-psk wifi-sec.psk "secret_passphrase"
nmcli con up Hotspot

This creates a “test” network with the password “secret_passphrase”. The connection to identify this setup in the Network Manager is called Hotspot. This kind of WLAN access point assigns each client an own IP Address in its own sub net, starting with 10.42.0.1 by default. Accesses to the internet over an ethernet connection are using NAT (network address translation). This way the clients are not visible from the ethernet.

To remove this connection use:

Code Block
nmcli con delete Hotspot

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The init system changed from System V to systemd. This means that all scripts in /etc/init.d are gone and replaced by systemd units. systemd uses so-called unit-files to configure services to start and stop. The tool systemctl is the main userspace tool to control these if needed.

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The hardware watchdog device on SECO Northern Europe devices is capable to execute a hardware reset when not triggered in time. The device node for the hardware watchdog is /dev/watchdog.

The watchdog service is able to monitor different system parameters, like the system load, and can take different actions if any system parameter is out of a defined range. Those repair actions can be simple cleanup scripts or the execution of a reboot or shutdown.

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title	Configure watchdog

The file /etc/systemd/system.conf contains option to configure the watchdog logic.

Code Block
RuntimeWatchdogSec=0

Default value of 0 means watchdog is disabled, set to a value (e.g. 20s) to reboot the system after there is no keep-alive ping during the given interval.

Code Block
RebootWatchdogSec=10min ShutdownWatchdogSec=10min KExecWatchdogSec=0

Further configuration to watchdog timing at reboot, shutdown, and by kexec, respectively.

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title	Add watchdog logic to running service

To add the watchdog logic to a running service, simply add WatchdogSec=<interval> to the systemd unit file of that service.

Code Block
[Unit] Description=My unit [Service] ExecStart=/usr/bin/myunit WatchdogSec=30s Restart=on-failure

Further documentation and additional configuration can be found here and here.

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The common Unix/Linux utilities to shutdown the system behave accordingly:

reboot: will stop all login-services, stop all running applications, flush all caches, unmount all filesystems and safely reboot the system.
halt: will stop all login-services, stop all running applications, flush all caches, unmount all filesystems and just "halt" the system, so that a user may safely disconnect the power-supply without risking any data-loss.
poweroff: according to Unix/Linux conventions for systems that cannot turn-off themselves, will do just the same as halt.

This means, as per Linux/Unix convention for systems that can’t turn-off themselves, none of these commands will turn-off device power; not even the display power. The halt and poweroff commands will only ensure that the system is put in a state, where no user-processes are running anymore and all data has been written back to storage media.

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Note
Be careful changing the command line, as it can easily break the booting process of your device. If booting fails after those changes, you will need to boot into Flash-N-Go System and correct the settings. In this case, please refer to the Flash-N-Go infrastructure manual.

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title	Open and edit the command line

To change the kernel command line, the boot partition needs to be mounted:

Code Block
mount /dev/mmcblk0p2 /mnt

Open the boot configurator file to edit:

Code Block
nano /mnt/boot.cfg

The boot configuration normally looks similar to this:

Code Block

# Only load linux image as it also contains the configured devicetree attached
load linuximage
exec "console=ttymxc0,115200 root=/dev/mmcblk0p3 rootflags=data=journal rootwait rootfstype=ext4 cma=128M loglevel=6 vt.global_cursor_default=0 vt.color=0xF7 fbcon=logo-pos:center,logo-count:1,rotate:0"

The last line is the kernel command line. Options can be added to the end.

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By default SECO Northern Europe devices come with the SECO logo as the boot logo at startup. If this is not desired by the customer, the logo can be disabled by adding the parameter “logo.nologo” to the Kernel command line as described above.

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title	Disabling bootlogo

Edit the boot.cfg file as shown (adding logo.nologo to the last line):

Code Block

# Only load linux image as it also contains the configured devicetree attached
load linuximage
exec "console=ttymxc0,115200 root=/dev/mmcblk0p3 rootflags=data=journal rootwait rootfstype=ext4 cma=128M loglevel=6 vt.global_cursor_default=0 vt.color=0xF7 fbcon=logo-pos:center,logo-count:1,rotate:0 logo.nologo"

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By default the system time is automatically synced from an NTP Server and user should not need to do any change. However, it is possible to set a custom time for the system using the command timedatectl.

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title	Modifying system time with timedatectl

Calling timedatectl will report the current time

Code Block

root@localhost:~# timedatectl
               Local time: Wed 2022-11-02 16:25:24 CET
           Universal time: Wed 2022-11-02 15:25:24 UTC
                 RTC time: Wed 2022-11-02 15:25:24
                Time zone: Europe/Berlin (CET, +0100)
System clock synchronized: yes
              NTP service: active
          RTC in local TZ: no

To change the time of the device, first NTP Synchronisation must be disabled, then time can be set with the parameter set-time

Code Block

root@localhost:~# timedatectl set-ntp FALSE
root@localhost:~# timedatectl set-time "2022-11-11 08:09:00"
root@localhost:~# timedatectl
               Local time: Fri 2022-11-11 08:09:03 CET
           Universal time: Fri 2022-11-11 07:09:03 UTC
                 RTC time: Fri 2022-11-11 07:09:03
                Time zone: Europe/Berlin (CET, +0100)
System clock synchronized: no
              NTP service: inactive
          RTC in local TZ: no

To use a different NTP server, the config file /etc/systimed/timesyncd.conf can be modified.

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SECO Northern Europe devices can automatically load customized drivers (module) on boot with the help of systemd. The systemd-modules-load.service is responsible for external module loading on system startup. Users can customize this service to integrate their own driver to the system.

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title	Load a customized driver

First check if systemd-modules-load.service is activated:

Code Block
root@santaro:~# systemctl status systemd-modules-load.service

Create the config file in /etc/modules-load.d/:

Code Block
root@santaro:~# cd /etc/modules-load.d/ root@santaro:/etc/modules-load.d/# touch <module-name>.conf

Edit the file to only contain the module name:

Code Block
<module-name>

Next time the system reboots, the module will be automatically loaded.

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Old Version 15

New Version Current

Key

SECO Northern Europe system configuration

Network configuration

WLAN

Page Comparison

Versions Compared

Old Version 15

New Version Current

Key

SECO Northern Europe system configuration

Network configuration

WLAN