Mihini/Run Mihini on an Open Hardware platform

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This page describes a scenario for illustrating the use of Mihini on an Open Hardware Linux-based platform such as BeagleBoard or RaspberryPi.

The goal would be for someone to be able to be only one hour away from taking a bare development board and have it configured to collect data out of the GPIO sensors.

Please bear in mind that Mihini is still under development.

Contents

Step 1 - Build Mihini

So far, all the work is being done directly on your remote system. For the following sample, pi user is being used on a RaspberryPi running Raspbian Wheezy. Connect to you device using ssh and follow the steps.

$ ssh pi@raspberry.local

Compilation prerequisites

First of all, you will need some compilation tools:

$ sudo apt-get install build-essential cmake git telnet

Sources to compile

Get the sources [NOTE: the source code of Mihini is not yet available. Still, we wanted to work on this detailed tutorial in parallel of the IP review process...]

$ cd
$ git clone git://git.eclipse.org/gitroot/mihini/org.eclipse.mihini.git mihini-repo

Run the compilation

Lets move into the repository you just cloned. Make sure you have all prerequisites mentioned above installed. Now, simply run the following in the repository you just cloned, here called mihini/.

# Compile Mihini
$ cd mihini
$ ./bin/build.sh
 
# Compile Lua
$ cd build.default/
$ make lua

Configure Mihini

Then there are some configuration items in build.default/runtime/lua/agent/defaultconfig.lua that you may optionally want to modify.

OPTIONAL (but useful :))

  • Enable Lua shell on all network interfaces by adding
    • shell.address = "*"
  • Disable colors while logging , in order to not clutter your syslog.
    • log.enablecolors = false

It should be easier

What is explained above is just a beginning. We are about to provide material which will speed up previous steps, such as:

  • How to cross compile Mihini from your Desktop machine
  • A defaultconfig.lua with the right default settings
  • A Linux package, to avoid any kind of compilation or configuration ( It is hypothetical )


Step 2 - Start Mihini on your device

One of the features of Mihini is to manage the life cycle of your application. In order to do so, applications are run from another program: the Appmon. We need to start it.

Manually

On your device, here a RaspberryPi with user pi.

$ cd /home/pi/mihini/build.default
$ sudo ./runtime/bin/appmon_daemon -a /home/pi/mihini/build.default/runtime/start.sh -w /home/pi/mihini/build.default/runtime -u pi -g pi -n 5 2>&1 | logger -t Mihini

Notice: we launched appmon_daemon and mihini with root user rights, and applications managed by appmon_daemon will be launched using user pi that should give sufficient user rights for most of needs.

Stop Mihini manually

$ sudo killall agent
$ sudo killall appmon_daemon

As a service

Soon :)

Step 3 - Setup Koneki environment

  • Download Lua Development Tools
  • Install Remote Development Support for LDT
  • Configure the remote target in the Koneki environment
    • Define your device and configure its "SSH Lua" paths like this
      SshLuaConfiguration.png
      • If you want the text version
LUA_PATH: /home/pi/mihini/lib/?.lua;/home/pi/mihini/lib/?/init.lua;/home/pi/mihini/lua/?.lua;/home/pi/mihini/lua/?/init.lua;./?.lua
LUA_CPATH: /home/pi/mihini/lib/?.so;/home/pi/mihini/lua/?.so
LD_LIBRARY_PATH: $LD_LIBRARY_PATH:/home/pi/mihini/lib
  • Configure the "Mihini execution environment" (coming soon, will provide nice autocompletion...)
  • Create a launch/debug configuration and test your script.

Step 4 - Create your first application

You could blink a LED, use a touch sensor, measure the temperature and available RAM of the board... I decided to keep it simple in this tutorial, my application will simply log :). The file is main.lua.

local log   = require "log"
local sched = require "sched"
local function main()
    log("GENERAL", "INFO", "My first Mihini app is alive :)")
end
 
sched.run(main)
sched.loop()

Step 5 - Install your application

Manually

All you a have to do in order to enable Mihini to handle you application is:

  1. Create a launcher
  2. Provide sources

Create a launcher

Mihini Application container runs executables. To run a Lua application, we need to set some variables beforehand and then lauch your application. In order to do so lets create the proper launcher. In the Mihini world, it is an executable file called run. Here is its content:

#!/bin/sh
 
# Setting up paths
export LUA_PATH="/home/pi/mihini/lib/?.lua;/home/pi/mihini/lib/?/init.lua;/home/pi/mihini/lua/?.lua;/home/pi/mihini/lua/?/init.lua;./?.lua"
export LUA_CPATH="/home/pi/mihini/lib/?.so;/home/pi/mihini/lua/?.so"
export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:/home/pi/mihini/lib"
 
# Running app
/home/pi/mihini/bin/lua main.lua

Now the my application folder looks like

$ find raspapp/
raspapp/
raspapp/run
raspapp/main.lua

Install application

First of all, I presume you already have an Appmon Daemon running. You may wonder which way you can interact with Mihini. While starting, Mihini opens a Telnet server on port 2000, it enables you communicate with its runtime. We are about to use it to install an app available at '/tmp/raspapp', which will be named 'sample', this application will benefit from autostart ( the last true parameter ).

$ telnet localhost 2000
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Lua interactive shell
> appcon = require 'agent.appcon'
> = appcon.install('sample', '/tmp/raspapp', true)
2013-01-22 13:33:45 APPCON-INFO: Installing application "sample"
= ok

We can check that the application is properly installed

> for app, t in pairs(appcon.list()) do
+     print( app )
+     for field, data in pairs(t) do
+         print("\t", field, data)
+     end
+ end
sample
                autostart       true
                runnable        true

Notice: CTRL-D to quit.

We can even check logs:

$ cat /var/log/syslog | grep Mihini

Over the air

One day, it will be possible to install application to your remote system Mihini just from its IP, and even more:

  • Use the Koneki tools to create an application package
  • Deploy the package on a publically available web server
  • Connect to the Mihini console and for a connection to the testing server

MISC. TIP & TRICKS

  • You may want to have udev rules so as your USB devices (typically the 3G stick) does not end up having an always changing /dev/ttyUSB<something> file descriptor...
    • For a Sierra 3G stick, create a 99-aircard.rules in /etc/udev/rules.d, with the following rules (your ID_VENDOR_ID and ID_MODEL_ID may be different):

SUBSYSTEM=="tty", SUBSYSTEMS=="usb", ENV{ID_VENDOR_ID}=="1199", ENV{ID_MODEL_ID}=="68a3", ENV{ID_USB_INTERFACE_NUM}=="03", SYMLINK+="ttyATConsole0" SUBSYSTEM=="tty", SUBSYSTEMS=="usb", ENV{ID_VENDOR_ID}=="1199", ENV{ID_MODEL_ID}=="68a3", ENV{ID_USB_INTERFACE_NUM}=="04", SYMLINK+="ttyATConsole1"

TODO

  • Remove Lua comments to save some flash on very tiny devices (could probably be part of the build process btw)
    • find . -type f -name '*.lua' -print0 | xargs -0 sed -i '/^[ \t]*--/d'
  • Strip binary code, to save flash too
    •  find . -type f -name '*.so' -print0 | xargs -0 $STRIP_EXECUTABLE_PATH