Using Kubos Linux¶
Overview¶
This document is intended as a general guide for creating, loading, and using Kubos projects and other files within the user space of Kubos Linux.
Communicating with an OBC¶
There are currently two primary methods for users to communicate directly with their OBCs:
- Via a debug UART port
- Via an ethernet port (not supported by all boards)
Debug Console¶
Each board will have some debug port available, which will then be connected to your computer via USB. See the appropriate Working with {board} document for more information.
If the target board is correctly connected to your host computer, you should see a /dev/ttyUSB* device in your Vagrant box. The VM is set up to automatically forward any FTDI cables that connect to a /dev/FTDI device for ease-of-use.
The Vagrant image comes pre-packaged with a minicom serial connection configuration file. You can connect with this configuration file using the command
$ minicom kubos
Alternatively, you can manually create a serial connection with minicom (or other terminal application) using the following connection configuration:
| Setting | Value |
|---|---|
| Baudrate | 115200 |
| Bits | 8 |
| Parity | N |
| Stop Bits | 1 |
Once connected, you can log in using either a user that you’ve created, or root, which has a default password of ‘Kubos123’.
Fully logged in, the console should look like this:
Welcome to Kubos Linux
Kubos login: root
Password:
Jan 1 00:00:16 login[212]: root login on 'ttyS0'
~ #
Warning
Please make sure to either logout of your board, or change it back to the root user’s home directory before beginning any file transfer
Ethernet¶
Some OBCs support communication via an ethernet port. Once configured, this port can be used as an alternate method to access the board’s shell interface and to transfer files.
Setup¶
Connect an ethernet cable from the board to either your computer or an open network port.
Log into the board using the debug console and then edit /etc/network/interfaces.
Update the IP address field to be an address of your choosing.
Once updated, run the following commands in order to make the board use the new address:
$ ifdown eth0; ifup eth0
The address can be verified by running the ipaddr command
Communicating via SSH¶
Once a board has been given a valid IP address, you can create an SSH connection to it.
This can be done from either the SDK or your host machine.
To connect from the command line, run ssh kubos@{ip-address}.
You will be prompted for the kubos account password.
You can also use a tool, like PuTTY, to create an SSH connection.
File Transfer¶
Once the IP address has been set, you can also transfer files to and from the stack using the scp command.
Again, this command can be run from either the SDK or your host machine.
For example, if I wanted to send a file on my host machine, test.txt, to reside in the kubos account’s home directory,
given a stack IP of 10.50.1.10, I would enter:
$ scp test.txt [email protected]:/home/kubos
User Applications¶
User applications are created, built, and flashed onto a target board as Kubos SDK projects.
Building a Project¶
Projects are created and built with the standard Kubos SDK commands.
For example:
$ kubos init -l newproj
$ kubos target kubos-linux-isis-gcc
$ kubos build
Note
You must use the -l|--linux option with kubos init in order
to properly create a project for Kubos Linux.
Configuring a Project¶
Once a project has been created, it can be configured with the project’s config.json file. This file is not created by default, so will need to be manually created. It will reside in the top-level directory of the Kubos SDK project.
More information about project configuration can be found in the Kubos Project Configuration doc.
There are a few relevant configuration options for Kubos Linux:
Updating Credentials¶
Ideally, you should not be using the default root user password. If
you’ve changed it, you’ll need to pass the new password to the Kubos
flash utility through the config.json file, which should be located in
the top-level directory of your project. You’ll need to create the file
if it doesn’t already exist. Update the system.password parameter with
the password to use.
If you’re creating a brand new config.json file, you can just copy and paste the text below (newpass should be your desired password):
{
"system" : {
"password" : "newpass"
}
}
Setting Initialization Configuration¶
There are several config.json options available which customize how and
when a user application is started:
- system.initAfterFlash - (Default: false) Tells the Kubos SDK whether to start the application as a background daemon after flashing it to the board.
- system.initAtBoot - (Default: false) Tells the Kubos SDK whether to generate and install an initialization script.
- system.runLevel - (Default: 50. Range: 10-99) Sets priority of initialization script.
When the system.initAfterFlash option is turned on, the user
application will be started as a background daemon at the end of the
kubos flash process. This is done using Linux’s
start-stop-daemon command. By default this feature is turned off, so
the value of the option will need to be set to “true” by the user in
order to turn it on.
If enabled, an initialization script will be generated and installed during the flashing process. This script will follow the naming convention of “S{runLevel}{applicationName}”, where “runLevel” is the initialization priority order of the script. All user application init scripts will be run after all of the Kubos init scripts, but within the user scripts, the scripts with the lowest run level will be executed first. So an application with a run level of 10 will be initialized before an application with a run level of 50.
The run level of an initialization script can be changed after initially
flashing the script to the board. Simply change the system.runLevel
value, rebuild the project, and then reflash it to the board. The old
script will be removed as part of the flash process.
Flashing an Application¶
The board should be connected to your computer and it should be fully powered.
Warning
Please make sure to either logout of your board, or change it back to the root user’s home directory before beginning any file transfer
Assuming you’ve successfully built a Kubos SDK project for the desired target,
when you issue the kubos flash the output should look like this:
info: found newproj at source/newproj
Compatible FTDI device found
Sending file to board...
Bytes Sent: 693248/1769379 BPS:8343 ETA 02:08
Transfer Successful
Execution time: 21 seconds
The application binary will be loaded into the /home/system/usr/bin directory on the target board.
If the ‘system.initAtBoot’ option has been turned on, then a standard initialization script will be generated and flashed into the /home/system/etc/init.d directory automatically during the application flashing process.
If the ‘system.initAfterFlash’ option has been turned on, then the application will be started as a background service as the last step in the application flashing process.
Example Program¶
Let’s walk through the steps to create the example Kubos Linux project.
Initialize the project
$ kubos init --linux newproj
Move into the project folder
$ cd newproj
Set the project target
$ kubos target kubos-linux-isis-gcc
Build the project
$ kubos build
Flash the project
$ kubos flash
Log into the board
$ minicom kubos
Login: root/Kubos123
Run the example application
$ newproj
Output should look like this:
Initializing CSP
Starting example tasks
Ping result 80 [ms]
Packet received on MY_PORT: Hello World
Ping result 90 [ms]
Packet received on MY_PORT: Hello World
Ping result -1 [ms]
Packet received on MY_PORT: Hello World
Ping result 60 [ms]
Packet received on MY_PORT: Hello World
Ping result 50 [ms]
Packet received on MY_PORT: Hello World
Press Ctrl+C to exit execution.
Press Ctrl+A, then Q to exit minicom.
Flashing Non-Application Files¶
Warning
Please make sure to either logout of your board, or change it back to the root user’s home directory before beginning any file transfer
If you would like to flash a file other than the application binary onto your board, you can add an additional parameter to the usual flash command:
$ kubos flash {absolute-path-of-file}
If the name of the file matches the name of the application, as specified in the module.json file, then the file is assumed to be the application binary and will be loaded into /home/system/usr/bin on the target board.
If the name of the file ends in *.itb, the file is a Kubos Linux upgrade package and will be loaded into the upgrade partition of the target board. An internal variable will be set so that the upgrade package will be installed during the next reboot of the target board.
All other files are assumed to be non-application files (ex. custom shell scripts) and will be loaded into /home/system/usr/local/bin. Once they have been flashed, these files can then be manually moved to another location.
Note
The file does not need to reside within a Kubos SDK project,
but the kubos flash command must still be run from the project,
since that is where the target configuration information is stored.
For example:
$ kubos flash /home/vagrant/not-my-project/test-util.sh
Flash Troubleshooting¶
See the Flash Troubleshooting of our FAQ guide for troubleshooting tips.
Manual File Transfer¶
If for some reason you want to manually transfer a specific file onto the target board, for example a custom script, you’ll need to do the following:
Connect to the board through minicom (the file transfer protocol is not guaranteed to work with any other terminal program)
$ minicom kubos
Login to the board
Welcome to minicom 2.7
OPTIONS: I18n
Compiled on Feb 7 2016, 13:37:27.
Port /dev/FTDI, 21:26:43
Press CTRL-A Z for help on special keys
Welcome to Kubos Linux
(none) login: root
Password:
Jan 1 00:00:11 login[210]: root login on 'ttyS0'
~ #
Navigate to the location you’d like the received file to go.
~ # mkdir righthere
~ # cd righthere
~/righthere #
Issue the zModem command to prep the board to receive a file
$ rz -bZ
Press Ctrl+a, then press s to open the minicom file transfer dialog.
+-[Upload]--+
| zmodem |
| ymodem |
| xmodem |
| kermit |
| ascii |
+-----------+
Select zmodem
+-------------------[Select one or more files for upload]-------------------+
|Directory: /home/vagrant |
| [..] |
| [linux] |
| [newprj] |
| minicom.log |
| |
| ( Escape to exit, Space to tag ) |
+---------------------------------------------------------------------------+
[Goto] [Prev] [Show] [Tag] [Untag] [Okay]
Select the file to send:
Press g to open the Goto dialog and navigate to the desired folder
(full pathname required).
Press enter to open the file selector dialog and specify the file you want within the current folder.
+-------------------[Select one or more files for upload]-------------------+
|Directory: /home/vagrant/linux/build/kubos-linux-isis-gcc/source |
| [..] |
| [CMakeFiles] |
| CMakeLists.txt |
| CTestTestfile.cmake |
| cmake_install.cmake |
| linux |
| linux.map |
| +-----------------------------------------+ |
| |No file selected - enter filename: | |
| |> linux | |
| +-----------------------------------------+ |
| |
| ( Escape to exit, Space to tag ) |
+---------------------------------------------------------------------------+
[Goto] [Prev] [Show] [Tag] [Untag] [Okay]
You should see a progress dialog as your file is transferred to the board.
+-----------[zmodem upload - Press CTRL-C to quit]------------+
|^XB00000000000000rz waiting to receive.Sending: linux |
|Bytes Sent: 41984/ 99084 BPS:8905 ETA 00:06 |
| |
| |
| |
| |
| |
+-------------------------------------------------------------+
Once file transfer is complete, you should be able to press enter and use your new file
+-----------[zmodem upload - Press CTRL-C to quit]------------+
|^XB00000000000000rz waiting to receive.Sending: linux |
|Bytes Sent: 99084 BPS:7982 |
| |
|Transfer complete |
| |
| READY: press any key to continue... |
| |
+-------------------------------------------------------------+
Press Ctrl+a, then q to bring up the dialog to exit minicom. Hit enter to quit without reset.
Using Peripherals¶
Each board has a variety of different ports available for interacting with peripheral devices. Currently, users should interact with these devices using the standard Linux functions. A Kubos HAL will be added in the future.
Please refer to the appropriate Working with {board} document for more information about the specific peripheral availability.
User Accounts¶
In general, it is preferred to use a non-root user account to interact
with a Linux system. A default user account ‘kubos’ is included with
Kubos Linux. Other user accounts can be created using the standard Linux
commands (adduser, useradd, etc).
All user accounts should have a home directory in the format ‘/home/{username}’.
The passwd command can be used to change the password of existing user
accounts.
If you change the root user’s password, be sure to also update the password in any Kubos SDK project configurations.
Kubos Linux File System¶
There are a few key directories residing within the Kubos Linux user space.
/home¶
All user-created files should reside under the /home directory. This directory maps to a separate partition from the root file system. As a result, all files here will remain unchanged if the system goes through a kernel upgrade or downgrade.
The home directories of all user accounts, except root, should live under this directory.
Warning
Any files not residing under the /home directory will be destroyed during an upgrade/downgrade
/home/system/usr/bin¶
All user-created applications will be loaded into this folder during the
kubos flash process. The directory is included in the system’s PATH,
so applications can then be called directly from anywhere, without
needing to know the full file path.
/home/system/usr/local/bin¶
All user-created non-application files will be loaded into this folder
during the kubos flash process. There is currently not a way to set
a destination folder for the kubos flash command, so if a different
endpoint directory is desired, the files will need to be manually moved.
/home/system/etc/init.d¶
All user-application initialization scripts live under this directory. The naming format is ‘S{run-level}{application}’.
Resetting the Boot Environment¶
Note
This is a case which normal users should never encounter, but becomes more likely when initially testing custom Kubos Linux builds. Due to the blocking nature of the behavior, this information has been included in this doc in order to make it more prominent.
If the system goes through the full recovery process and the bootcount is still exceeded, it will present the U-Boot CLI instead of attempting to boot into Kubos Linux again.
If this occurs, follow the instructions for resetting the boot environment.