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{{todo|Port/Polish (11.15.13-11:35->KY+)|Klint Youngmeyer|project=oe 4,oe 5,ky,inprogress}}
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{{todo|SEOKWREV (11.25.13-17:30->KY+);(11.26.13-21:25->MD+);(11.27.13-12:15->KY+);(12.05.13-01:00->MD+);(12.05.13-11:35-KY+);(12.19.13-13:45-MG+);(03.04.14-15:15->BS-);(03.07.14-15:35->BS+)|Klint Youngmeyer|project=oe 4,oe 5,ky,md,mg,bs,SEOKWREV}}
  
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{{#seo:
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|title=Quick Reference
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|titlemode=append
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|keywords=Quick Reference,Terminal,Filesystem,Network Interfaces,Remote Access
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|description=A quick reference guide to assist with the initial learning curve.
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}}
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This page is a quick reference guide to assist with the initial learning curve. Once full familiarity with the development environment is established, this quick reference will likely no longer be needed.
 
== Working With the Terminal ==
 
== Working With the Terminal ==
 +
Use <code>minicom</code> to bring up a serial terminal.  To configure the serial console, run <code>sudo minicom -s</code>. The settings needed for configuring <code>minicom</code> can be found [[Serial_Connections|on this page]]. Select, <code>Save as dfl</code>, to save the settings you have configured to be the default settings whenever you run <code>minicom</code>.  Use <code>minicom -o</code> to start <code>minicom</code> more quickly; the <code>-o</code> option tells <code>minicom</code> to start without sending <code>AT</code> commands to initialize a modem.
  
 +
The <code>dialout</code> group, on many systems, will enable group members to use minicom without having to run it as root (without using sudo).  To add your user account, such as <code>employee</code>, to the group, run this command as the <code>root</code> user:
 +
 +
<syntaxhighlight lang="text">
 +
$ adduser employee dialout
 +
</syntaxhighlight>
 +
 +
== Editing a File ==
 +
EMAC OE provides simple text editing capabilities for making changes to configuration files and scripts. Major editing tasks should be performed on a desktop system first, copying the desired files back to the target board. There are two text editors available on standard EMAC OE builds: <code>vi</code> and <code>nano</code>. <code>vi</code> is a very common text editor available on almost every Unix-like OS. <code>nano</code> is a more conventional text editor that can be easier to use for those not familiar with <code>vi</code>.
 +
 +
To edit a file with <code>vi</code>, run the command:
 +
<syntaxhighlight lang=console>
 +
root@emac-oe:~# vi <filename>
 +
</syntaxhighlight>
 +
To edit a file with <code>nano</code>, run the command:
 +
<syntaxhighlight lang=console>
 +
root@emac-oe:~# nano <filename>
 +
</syntaxhighlight>
 +
For a more detailed overview, see this [[Editing_a_File | page]]
  
 
== Making Changes To The Target Machine's Fileystem ==
 
== Making Changes To The Target Machine's Fileystem ==
 +
By default, the flash filesystem on most EMAC devices is mounted read-only.  To make changes to the filesystem, it will have to be remounted as read-write.  This can be done with the following command:
 +
 +
<syntaxhighlight lang=console>
 +
root@emac-oe:~# mount -o remount,rw /</syntaxhighlight>
 +
 +
To mount the filesystem as read-only again (without rebooting), type:
  
 +
<syntaxhighlight lang=console>
 +
root@emac-oe:~# mount -o remount,ro /</syntaxhighlight>
  
 
==Mounting a Flash Filesystem==
 
==Mounting a Flash Filesystem==
  
 +
<!--'''SINCE THIS IS A QUICK REFERENCE DOCUMENT, THIS SECTION SHOULD PROBABLY BE SPLIT OFF INTO ITS OWN PAGE.  The gist of how to do this could then be shown here, with a link to the separate document for more in-depth info.'''-->
 +
 +
There are four steps to mounting a flash filesystem on our EMAC OE machine:
 +
<cl>
 +
1. Determine which device node is assigned to the flash device.
 +
<syntaxhighlight lang=console>root@emac-oe:~# dmesg | tail -n 15</syntaxhighlight>
 +
* Determine which partition to mount.
 +
* Determine where to mount the device.
 +
<syntaxhighlight lang=console>root@emac-oe:~# mkdir /mnt/myflash</syntaxhighlight>
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* Mount the device.
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<syntaxhighlight lang=console>root@emac-oe:~# mount /dev/sda1 /mnt/myflash</syntaxhighlight>
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</cl>
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<br clear=all>
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{{mbox  | type=notice | text='''NOTE''': You '''must''' have <code>root</code> permissions to perform some of the following steps.  Make sure you are logged in as the <code>root</code> user prior to performing the following steps.  The <code>su</code> command can be useful for this.  The filesystem will also need to be mounted read/write in order to create the directory mentioned below.  See the section regarding remounting the root filesystem as read/write (above) to see how to do this.}}
 +
<br clear=all>
 +
 +
For detailed instructions, please see the [[Mounting a Flash Filesystem]] page.
 +
 +
== Network Interfaces ==
 +
The <code>ifup</code> and <code>ifdown</code> commands may be used to enable (or, respectively, disable) network interfaces based on interface definitions in the file <code>/etc/network/interfaces</code>.
 +
 +
An example of using the <code>ifup</code> command:
 +
<syntaxhighlight lang=console>
 +
root@emac-oe:~# ifup eth0
 +
</syntaxhighlight>
 +
 +
An example of using the <code>ifdown</code> command:
 +
<syntaxhighlight lang=console>
 +
root@emac-oe:~# ifdown eth0
 +
</syntaxhighlight>
 +
 +
To temporarily configure the <code>eth0</code> interface to have a static IP address, 192.168.1.125, to use a DNS server at 192.168.1.25, and to use a gateway at 192.168.1.1:
 +
 +
<syntaxhighlight lang=console>
 +
root@emac-oe:~# ifconfig eth0 up 192.168.1.125 netmask 255.255.255.0
 +
root@emac-oe:~# route add default gw 192.168.1.1
 +
root@emac-oe:~# echo "nameserver 192.168.1.25" > /etc/resolv.conf
 +
</syntaxhighlight>
 +
 +
== Remote Access==
 +
To access an EMAC product remotely, it is easiest to use <code>ssh</code> and <code>scp</code> for remote command execution and remote file transfer respectively.
 +
 +
To log into a system with the IP address 10.0.2.41, enter the following command:
 +
<syntaxhighlight lang=console>
 +
developer@ldc:~# ssh root@10.0.2.41
 +
</syntaxhighlight>
 +
 +
To execute a command on a remote system without opening a shell on the remote system (in this example, <code>ls -la</code>):
 +
<syntaxhighlight lang=console>
 +
developer@ldc:~# ssh root@10.0.2.41 'ls -la'
 +
</syntaxhighlight>
  
−
===Determining the Device Node Assigned to the Flash Device===
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To send the file ''example.text'' to the <code>/home</code> directory of a system with the IP address 10.0.2.41, enter the following command:
 +
<syntaxhighlight lang=console>
 +
developer@ldc:~# scp example.text root@10.0.2.41:/home
 +
</syntaxhighlight>
  
 +
To send the file ''example.txt'' to the home directory of the user account you're using to connect to a remote machine located at machine.example.com, enter the following command:
 +
<syntaxhighlight lang=console>
 +
developer@ldc:~# scp example.txt root@machine.example.com:
 +
</syntaxhighlight>
  
−
===Determine Which Partition to Mount===
+
''Note the colon at the end with nothing following it.  This also works with IP addresses.''
  
 +
== Running a User Program ==
 +
When a user program is uploaded, sometimes it does not have execute permissions. Use the following steps to ensure that your program functions properly.
 +
<cl>
 +
1. Navigate to the directory that the application was uploaded to (e.g. /tmp):
 +
<syntaxhighlight lang=console>
 +
root@emac-oe~:$ cd /tmp
 +
</syntaxhighlight>
 +
* Make the application file executable:
 +
<syntaxhighlight lang=console>
 +
root@emac-oe~:$ chmod u+x <filename>
 +
</syntaxhighlight>
 +
* Run the application:
 +
<syntaxhighlight lang=console>
 +
root@emac-oe~:$ ./<filename>
 +
</syntaxhighlight>
 +
</cl>
  
−
===Determine Where to Mount the Device===
 
  
 +
==See Also==
  
−
===Mount the Device===
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* [[Getting Started with Linux]]
 +
* [[Open Source Community]]
  
  
−
===Unmounting the Filesystem After Use===
+
<!-- [[Category: Support]] -->

Latest revision as of 14:46, 14 March 2014

TODO: {{#todo:SEOKWREV (11.25.13-17:30->KY+);(11.26.13-21:25->MD+);(11.27.13-12:15->KY+);(12.05.13-01:00->MD+);(12.05.13-11:35-KY+);(12.19.13-13:45-MG+);(03.04.14-15:15->BS-);(03.07.14-15:35->BS+)|Klint Youngmeyer|oe 4,oe 5,ky,md,mg,bs,SEOKWREV}}

This page is a quick reference guide to assist with the initial learning curve. Once full familiarity with the development environment is established, this quick reference will likely no longer be needed.

Working With the Terminal

Use minicom to bring up a serial terminal. To configure the serial console, run sudo minicom -s. The settings needed for configuring minicom can be found on this page. Select, Save as dfl, to save the settings you have configured to be the default settings whenever you run minicom. Use minicom -o to start minicom more quickly; the -o option tells minicom to start without sending AT commands to initialize a modem.

The dialout group, on many systems, will enable group members to use minicom without having to run it as root (without using sudo). To add your user account, such as employee, to the group, run this command as the root user: 

$ adduser employee dialout

Editing a File

EMAC OE provides simple text editing capabilities for making changes to configuration files and scripts. Major editing tasks should be performed on a desktop system first, copying the desired files back to the target board. There are two text editors available on standard EMAC OE builds: vi and nano. vi is a very common text editor available on almost every Unix-like OS. nano is a more conventional text editor that can be easier to use for those not familiar with vi.

To edit a file with vi, run the command: 

root@emac-oe:~# vi <filename>

To edit a file with nano, run the command: 

root@emac-oe:~# nano <filename>

For a more detailed overview, see this page

Making Changes To The Target Machine's Fileystem

By default, the flash filesystem on most EMAC devices is mounted read-only. To make changes to the filesystem, it will have to be remounted as read-write. This can be done with the following command: 

root@emac-oe:~# mount -o remount,rw /

To mount the filesystem as read-only again (without rebooting), type: 

root@emac-oe:~# mount -o remount,ro /

Mounting a Flash Filesystem

There are four steps to mounting a flash filesystem on our EMAC OE machine:

  1. Determine which device node is assigned to the flash device. 

    root@emac-oe:~# dmesg | tail -n 15

  2. Determine which partition to mount.

  3. Determine where to mount the device. 

    root@emac-oe:~# mkdir /mnt/myflash

  4. Mount the device. 

    root@emac-oe:~# mount /dev/sda1 /mnt/myflash


NOTE: You must have root permissions to perform some of the following steps. Make sure you are logged in as the root user prior to performing the following steps. The su command can be useful for this. The filesystem will also need to be mounted read/write in order to create the directory mentioned below. See the section regarding remounting the root filesystem as read/write (above) to see how to do this.


For detailed instructions, please see the Mounting a Flash Filesystem page.

Network Interfaces

The ifup and ifdown commands may be used to enable (or, respectively, disable) network interfaces based on interface definitions in the file /etc/network/interfaces.

An example of using the ifup command: 

root@emac-oe:~# ifup eth0

An example of using the ifdown command: 

root@emac-oe:~# ifdown eth0

To temporarily configure the eth0 interface to have a static IP address, 192.168.1.125, to use a DNS server at 192.168.1.25, and to use a gateway at 192.168.1.1: 

root@emac-oe:~# ifconfig eth0 up 192.168.1.125 netmask 255.255.255.0
root@emac-oe:~# route add default gw 192.168.1.1
root@emac-oe:~# echo "nameserver 192.168.1.25" > /etc/resolv.conf

Remote Access

To access an EMAC product remotely, it is easiest to use ssh and scp for remote command execution and remote file transfer respectively.

To log into a system with the IP address 10.0.2.41, enter the following command: 

developer@ldc:~# ssh root@10.0.2.41

To execute a command on a remote system without opening a shell on the remote system (in this example, ls -la): 

developer@ldc:~# ssh root@10.0.2.41 'ls -la'

To send the file example.text to the /home directory of a system with the IP address 10.0.2.41, enter the following command: 

developer@ldc:~# scp example.text root@10.0.2.41:/home

To send the file example.txt to the home directory of the user account you're using to connect to a remote machine located at machine.example.com, enter the following command: 

developer@ldc:~# scp example.txt root@machine.example.com:

Note the colon at the end with nothing following it. This also works with IP addresses.

Running a User Program

When a user program is uploaded, sometimes it does not have execute permissions. Use the following steps to ensure that your program functions properly.

  1. Navigate to the directory that the application was uploaded to (e.g. /tmp): 

    root@emac-oe~:$ cd /tmp

  2. Make the application file executable: 

    root@emac-oe~:$ chmod u+x <filename>

  3. Run the application: 

    root@emac-oe~:$ ./<filename>


See Also


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