{{WarningMessage|text=This application note was validated against specific versions of the kit only. It may not work with other versions. Supported versions are listed in the ''History'' section.}}
{{ImportantMessage|text=Regarding the Molex antenna used in this AN. It is valid only for '''No EU''' countries - see [https://www.lairdconnect.com/documentation/regulatory-information-tiwi-ble link]}}
== History ==
{| class="wikitable" border="1"
!Version
!XUELK version
!Date
!Notes
|-
|1.0.0
|1.1.3
|February 2017
|First public release
|-
|2.0.0
|March 1.1.3|April 2017|TBD*Added several packages to the root file system*Removed <code>busybox</code>*Added notes about physical interfaces|-|2.1.0|1.1.3|April 2017|*Added section ''Using the raw image''*Added notes about <code>ssh</code> server configuration*Added notes about <code>MySQL</code> server installation and configuration
|-
|}
==Introduction==
Several "distributions" are available for embedded Linux devices. [https://www.yoctoproject.org Yocto] and [https://buildroot.org Buildroot] are just two examples of the most common. Nevertheless, for some applications the use of a desktop/server distribution might be preferable. Since they are not conceived for embedded platforms, these distributions have to be carefully tailored, in order to match hardware resources.[1]
This application note shows how to run one of such distributions - Debian Jessie - on SBC Lynx. '''It is assumed that the reader if already familiar with''' [[AXEL_ULite_and_SBC_Lynx_Embedded_Linux_Kit_(XUELK)|'''AXEL ULite and SBC Lynx Embedded Linux Kit (XUELK)''']], as it is the basis of this work.
The procedure was tested on a an SBC Lynx with ConfigID=0x0000000C (PCB revision CS214515A), starting from XUELK 1.1.3 binaries.
*adding a modified version of the Linux kernel image [1]
*replacing the default Yocto root file system delivered along with the XUELK, with the Debian one. [2]
The following box shows how It is assumed that the microSD card is connected to perform the host machine. As such operations once , the card (mapped two partitions are mounted as <code>/devmedia/BOOT</code> and <code>/media/TBDROOTFS</code> in . The kernel image and the example) has been connected compressed archive containing the root file system are available for download at the following URLs respectively:* https://mirror.dave.eu/lynx/debian/20170403/xuelk-1.1.3_uImage.debian* https://mirror.dave.eu/lynx/debian/20170403/20170403-sbclynx-debian-8.tgz To copy the kernel image to a Linux host.the microSD card, issue the following command:
<pre class="board-terminal">
TBDcp -v xuelk-1.1.3_uImage.debian /media/BOOT/
</pre>
You can now remove Delete all the existing files in the <code>/media/ROOTFS</code> partition:<pre class="board-terminal">sudo rm -rf /media/ROOTFS/*sudo tar xvzf 20170403-sbclynx-debian-8.tgz -C /media/ROOTFS/ </pre>Decompress the Debian root file system in the same partition:<pre class="board-terminal">sudo tar xvzf 20170403-sbclynx-debian-8.tgz -C /media/ROOTFS/ </pre> Remove the card from the host, and plug it into the slot of SBC Lynx.
After powering it up, stop the automatic boot process, and edit the <code>mmcboot</code> variable as follows:
[1] The only difference with respect to the XUELK kernel image is related to the WiFi driver. To make it work with the Debian root file system, it has to be built as a loadable module instead of as a statically linked driver.
[2] The provided root file system is derived from this one: https://rcn-ee.com/rootfs/eewiki/barefs/debian-8.7-bare-armhf-2017-01-14.tar.xz.
===Using the raw image===
For convenience, the raw image of the microSD card is provided as well. This image is the result of the procedure described in the previous section, applied to a 16 GB card. The image can be downloaded [https://mirror.dave.eu/lynx/debian/20170403/20170403-sbclynx-debian-8-usd.zip here].
Once decompressed, it can be written directly to the card.
On a Linux host issue the following command (assuming the card is associated to the <code>/dec/sdc</code> device file):
In case your host is a Windows machine, you can use the well-known ''Win32 Disk Imager'' tool. It can be downloaded [https://sourceforge.net/projects/win32diskimager/ here].
[[File:Sbclynx-debian-disk-imager-win.png|thumb|center|600px|''Win32 Disk Imager'' tool]]
After installing it, open it and (see also the image above):
#select the raw image file
#select the drive letter of the microSD card
#press ''Write''.
==Adding packages==
Of course, one of the greatest - if not ''the'' greatest - pros of having a desktop distribution, is the availability of a huge archive of pre-built packages. They can be installed very easily with tools such as [https://wiki.debian.org/Apt <code>apt</code>] and [https://packaging.python.org <code>pip</code>].
Before installing packages, the network interface has to be configured, as it is disabled by default. To configure it with a static IP address (192.168.0.80 in the example), <code>nano</code> text editor can be used:
[ Wrote 9 lines ]
</pre>
Please note the that these changes will take effect after rebooting the machine.
DNS server has also to be enabled, in order to resolve URLs. Again, <code>nano</code> comes to help:
</pre>
You can finally install the desired packages, as shown in the following examples:
Cleaning up...
</pre>
===List of installed packages===
====deb packages====
Please click on the ''Expand'' button to see the list of the installed deb packages.