Axel Embedded Linux Kit (XELK)

Info Box Applies to Dacu Applies to Axel Ultra Applies to Axel Lite Applies to AXEL ESATTA

Introduction

Customers are strongly recommended to register their kits. Registration grants access to reserved material such as source code and additional documentation. To register the kit, please send an email to support-axel@dave.eu, providing the kit P/N and S/N.

Axel Embedded Linux Kit (XELK for short) provides all the necessary components required to set up the developing environment to:

• build the bootloader (U-Boot)
• build and run Linux operating system on Axel-based systems
• build Linux applications that will run on the target.

The main kit components are:

• hardware platform composed of
  • Axel system-on-module (SOM for short)
  • AxelEVB-Lite plugged on Dacu carrier board
  • 800x480 7" LVDS display
• Development virtual machine containing:
  • Toolchain
  • U-Boot bootloader sources
  • Linux kernel sources
  • Root file systems
• Technical documentation such hardware manuals, mechanical drawings, reference schematics, application notes etc.

The documents related to the software issues help the user to quickly start configuring the bootloader and the operating system, by hiding most of the complexity of the underlying hardware. For more details about Axel hardware characteristics, please refer to the Axel Hardware Manual. An account for the reserved area of DAVE Embedded Systems website is required to access the kit contents.

Kit Contents

Component	Description	Notes
	Axel Ultra SOM (or Axel Lite SOM) CPU: Freescale i.MX6 SDRAM: 2 GB DDR3 NOR: bootable SPI flash 32 MB NAND: 1GB	Please refer to Axel Ultra Hardware Manual
	AxelEVB-Lite Carrier board	Please refer to AxelEVB-Lite page
	Dacu Carrier board	Please refer to Dacu page
	Ampire AM-800480STMQW 7” 800x480 LCD display LVDS interface	Please refer to XELK Quick Start Guide
	AC/DC Single Output Wall Mount adapter Output: +12V – 2.0 A	Please refer to XELK Quick Start Guide
	DB9 Male Serial port adapter	Please refer to XELK Quick Start Guide
	MicroSDHC card with SD adapter and USB adapter	Please refer to XELK Quick Start Guide

XELK software components

DAVE Embedded Systems adds to the latest Linux BSP from NXP/Freescale the customization required to support the Axel platform. For this reason most of the documentation provided by NXP/Freescale remains valid for the XELK development kit. However, some customization is required, in particular at bootloader and linux kernel levels.

The following table reports the XELK releases information.

	XELK version
Release number	1.0.0	1.1.0	1.2.0	2.0.0	2.1.0	2.2.0	2.3.1	3.0.1	4.0.0
Release type	Major	Maintenance	Maintenance	Major	Maintenance	Maintenance	Maintenance	Major	Major
Status	Released	Released	Released	Released	Released	Released	Released	Released	Planned
Release date	November, 4th 2013	January 2014	May 2014	November 2014	May 2015	February 2016	October 2016	November 2017	Q2 2019
Release notes	Ver 1.0.0	Ver 1.1.0	Ver 1.2.0	Ver 2.0.0	Ver 2.1.0	Ver 2.2.0	Ver 2.3.1	Ver 3.0.1	Ver 4.0.0
SOM PCB version	Axel Ultra: CS030713	Axel Ultra: CS030713A	Axel Ultra: CS030713A Axel Lite: CS335013A	Axel Ultra: CS030713A Axel Lite: CS335013A	Axel Ultra: CS030713B Axel Lite: CS335013A	Axel Ultra: CS030713B Axel Lite: CS335013A	Axel Ultra: CS030713B Axel Lite: CS335013A Axel Lite: CS335013C	Axel Lite: CS335013A Axel Lite: CS335013C	Axel Lite: CS335013A Axel Lite: CS335013C
Supported carrier boards	AxelEVB-Lite Dacu	AxelEVB-Lite Dacu	AxelEVB-Lite Dacu	AxelEVB-Lite Dacu	AxelEVB-Lite AxelEVB-Lite rev.A Dacu	AxelEVB-Lite AxelEVB-Lite rev.A Dacu SBCX	AxelEVB-Lite AxelEVB-Lite rev.A Dacu SBCX	AxelEVB-Lite AxelEVB-Lite rev.A Dacu SBCX	AxelEVB-Lite AxelEVB-Lite rev.A Dacu SBCX
U-Boot version	2013.10-xelk-1.0.0	2013.10-xelk-1.1.0	2013.10-xelk-1.2.0	2013.04-xelk-2.0.0	2013.04-xelk-2.1.0	2013.04-xelk-2.2.0	2013.04-xelk-2.3.1	2016.03-xelk-3.0.2	2017.03-xelk-4.0.0
Linux version	3.0.35-xelk-1.0.0	3.0.35-xelk-1.1.0	3.0.35-xelk-1.2.0	3.10.17-xelk-2.0.0	3.10.17-xelk-2.1.0	3.10.17-xelk-2.2.0	3.10.17-xelk-2.3.1	4.1.15-xelk-3.0.0	4.9.11-xelk-4.0.0
Drivers	SPI NOR Flash (boot) UART debug (2-wire) USB Host USB OTG SD/MMC1 CAN Touch screen controller EMAC SATA HDMI LVDS0	SPI NOR Flash (boot) UART debug (2-wire) USB Host USB OTG SD/MMC1 CAN Touch screen controller EMAC SATA HDMI LVDS0 NAND RTC I2C SPI	SPI NOR Flash (boot) UART debug (2-wire) USB Host USB OTG SD/MMC1 CAN Touch screen controller EMAC SATA HDMI LVDS0 NAND RTC I2C SPI	SPI NOR Flash (boot) UART debug (2-wire) USB Host USB OTG SD/MMC1 CAN Touch screen controller EMAC SATA HDMI LVDS0 NAND RTC I2C SPI Video Input (MIPI)	SPI NOR Flash (boot) UART debug (2-wire) USB Host USB OTG SD/MMC1 CAN Touch screen controller EMAC SATA HDMI LVDS0 NAND RTC I2C SPI Video Input (MIPI) PCIe ConfigID	SPI NOR Flash (boot) UART debug (2-wire) USB Host USB OTG SD/MMC1 CAN Touch screen controller EMAC SATA HDMI LVDS0 NAND RTC I2C SPI Video Input (MIPI) PCIe ConfigID Splash screen (U-Boot) [1]	SPI NOR Flash (boot) UART debug (2-wire) USB Host USB OTG SD/MMC1 CAN Touch screen controller EMAC SATA HDMI LVDS0 NAND RTC I2C SPI Video Input (MIPI) PCIe ConfigID Splash screen (U-Boot) [1]	SPI NOR Flash (boot) UART debug (2-wire) USB Host USB OTG SD/MMC1 CAN Touch screen controller EMAC SATA HDMI LVDS0 NAND RTC I2C SPI Video Input (MIPI) PCIe ConfigID Splash screen (U-Boot) [1]	SPI NOR Flash (boot) UART debug (2-wire) USB Host USB OTG SD/MMC1 CAN Touch screen controller EMAC SATA HDMI LVDS0 NAND RTC I2C SPI Video Input (MIPI) PCIe ConfigID Splash screen (U-Boot) [1]
NXP/Freescale BSP version	L3.0.35-4.1.0	L3.0.35-4.1.0	L3.0.35-4.1.0	L3.10.17-1.0.0	L3.10.17-1.0.0	L3.10.17-1.0.3	L3.10.17-1.0.3	L4.1.15-2.0.0	L4.9.11_1.0.0
Graphic libraries	Qt 4.8	Qt 4.8	Qt 4.8	Qt 5.3.2	Qt 5.3.2	Qt 5.3.2	Qt 5.3.2	Qt 5.6.2	Qt 5.8
Build System	LTIB	LTIB	LTIB	Yocto Dora (1.5)	Yocto Dora (1.5)	Yocto Dora (1.5)	Yocto Dora (1.5)	Yocto Krogoth (2.1)	Yocto Morty (2.2)
Android							Kitkat 4.4.2	Marshmallow 6.0.1

[1] Splashscreen on LVDS0

Downloadable binary images

All binary images for XELK are hosted on DAVE Embedded System mirror server. There you can find a sub directory for each version of this development kit.

A summary of images with a brief description can be found into the table below:

In order to boot Linux from SD card files, the binary files must be renamed as follows: bootscript: boot.scr U-boot file u-boot.imx must be stored into first raw sector of the SD card using dd command

Image	XELK version 2.3.1
Platform	XELK rev.A	SBCX rev.A	SBCX rev.A	SBCX rev.B	SBCX rev.B
Carrier Board ConfigID	0001	0002	0003	0012	0013
LCD panel	Ampire 800 x 480 7" LVDS 262K colors (RGB666) (AM-800480STMQW-TA1 or AM-800480SETMQW-TA1H)
Touchscreen	resistive	resistive	capacitive	resistive	capacitive
bootscript	boot.scr	boot.scr
U-Boot	u-boot (Quad - boot from NOR)	u-boot (DualLite - boot from NAND)
Linux kernel	uImage
Linux kernel (Android 4.4.2)	uImage
Device tree (Quad processor)	imx6q-xelk-l.dtb	imx6q-sbcx-cb0002.dtb	Not available	imx6q-sbcx-cb0012.dtb	Not available
Device tree (DualLite processor)	imx6dl-xelk-l.dtb	imx6dl-sbcx-cb0002.dtb	imx6dl-sbcx-cb0003.dtb	imx6dl-sbcx-cb0012.dtb	imx6dl-sbcx-cb0013.dtb

Image	XELK version 3.0.1
Platform	XELK rev.A	SBCX rev.B	SBCX rev.B
Carrier Board ConfigID	0001	0012	0013
LCD panel	Ampire 800 x 480 7" LVDS 262K colors (RGB666) (AM-800480STMQW-TA1 or AM-800480SETMQW-TA1H)
Touchscreen	resistive	resistive	capacitive
bootscript	boot.scr	boot.scr
U-Boot	u-boot (Quad - boot from NOR)	u-boot (DualLite - boot from NAND)
Linux kernel	uImage
Device tree (Quad processor)	imx6q-xelk-l.dtb	imx6q-sbcx-cb0012.dtb	imx6q-sbcx-cb0013.dtb
Device tree (DualLite processor)	imx6dl-xelk-l.dtb	imx6dl-sbcx-cb0012.dtb	imx6dl-sbcx-cb0013.dtb

XELK microSD Layout

The microSD provided with XELK is used to store:

• A bootable partition (mmcblk0p1, vfat) containing:
  • binary images (u-boot and kernel images)
  • XELK documentation
  • XELK DVDK virtual machine image
• XELK root file system partition (mmcblk0p2, ext3)

XELK contains all the required software and documentation to start developing Linux application on the Axel platform. In particular, XELK provides a virtual machine, called DVDK, with the following features:

• VirtualBox virtual machine (.OVA archive)
• Based on Lubuntu 12.04 LTS (64-bit version)
• Pre-installed VirtualBox Guest Additions
• LXDE desktop environment
• Boot disk with the distro and pre-configured basic Linux services:
  • TFTP: with base directory /srv/tftp/
  • NFS: configured through the /etc/exports file
• Secondary disk containing source code and tools:
  • Bootloader (u-boot) source tree cloned from DAVE Embedded Systems public git repository
  • Linux kernel source tree cloned from DAVE Embedded Systems public git repository
  • External pre-built toolchain
  • Yocto bsp for AXEL
• Pre-installed Yocto-based root file systems with setup scripts, makefiles, example applications, ...
• Administrator account (dvdk) with autologin. Please note that the user account credentials are provided with the development kit (you can find them into the README file contained in the sw/dvdk folder of the kit distribution)

Please note that XELK u-boot and kernel source trees are derived from the official trees released by NXP/Freescale; these trees have been customized to add support for the Axel SOM.

XELK Updates

It's recommended to use the latest available XELK version. Please refer to Release notes for further information.

Updating git repositories

In XELK, the following source trees are clones of DAVE Embedded Systems public git repositories:

Component	GIT Remote	XELK Installation Directory
Linux	git@git.dave.eu:dave/axel/linux-2.6-imx.git	/home/dvdk/xelk/linux-2.6-imx
U-Boot	git@git.dave.eu:dave/axel/u-boot-imx.git	/home/dvdk/xelk/u-boot-imx
Yocto BSP	git@git.dave.eu:dave/axel/axel-bsp.git	/home/dvdk/xelk/axel-bsp

This means that these components can be kept in sync and up to date with DAVE Embedded Systems repositories.

RSA key generation

Please follow the procedure reported below to generate the RSA ssh key:

• select your username (ad es. username@myhost.com)
• start the DVDK and login into the virtual machine
• start a shell session
• enter the .ssh subdirectory into your home directory: cd ~/.ssh/
• launch the following command:
  

  ssh-keygen -t rsa -C "username@myhost.com" -f username@myhost.com

• this command creates the files ~/.ssh/username@myhost.com (private key) and ~/.ssh/username@myhost.com.pub (public key)
• edit your ~/.ssh/config adding the following lines:

Host git.dave.eu
    User git
    Hostname git.dave.eu
    PreferredAuthentications publickey
    IdentityFile ~/.ssh/username@myhost.com

Please send the public key file to one of the following email support addresses (depending on which SOM is included in your kit version)

• support-axel@dave.eu

with the request for the creation of a new public git account associated to your username. The support team will enable the account and send you a confirmation as soon as possible.

Synchronizing the repository

When the account is enabled, you can synchronize a source tree entering the repository directory and launching the git fetch command, like in the following example:

dvdk@dvdk-vm:~$ cd /home/dvdk/xelk/linux-2.6-imx/
dvdk@dvdk-vm:/home/dvdk/xelk/linux-2.6-imx$ git fetch origin

Please note that git fetch doesn't merge the commits on the current branch. To do that, you should run

git merge origin/axel

or replace the fetch-merge process with a single git pull command. Please note that the recommended method is the fetch-merge process. For further information on Git, please refer to Git Documentation.

Release types

XELK release type can be:

• Major, when substantial changes are applied to the BSP (eg: major kernel version upgrades) or to the development kit (eg: new features, build system updates, ..). This usually means that a new DVDK is created for the XELK release
• Maintenance, when minor updates and bug fixes are introduced. This usually means that the DVDK remains the same provided with the previous major version, and only an update of the source tree repositories (and the tftp binaries) is required

As an example, XELK 2.2.0 is a maintenance release, so it provides the DVDK released with the 2.0.0 major release; customers can easily upgrade to the 2.2.0 release by updating the software components as described in XELK Updates.

Release notes

After the XELK DVDK installation, please check for updates of the source tree repositories provided with the kit, as described in XELK Updates.

XELK 4.0.0

• Release date: N.A.
• Status: Working In Progress
• NXP Linux BSP: L4.9.11-1.0.0
• Supported carrier boards: AxelEVB-Lite on Dacu, SBCX

Notes

New MVM must be installed for using XELK-4.0.0. The VM is available for download on DAVE's XELK Reserved Area for registered users.

• Major change to NXP BSP 4.9.11
• Updated u-boot and kernel versions
• Updated Yocto version
• Updated Qt version

XELK 3.0.1

• Release date: 17/11/2017
• Status: released
• NXP Linux BSP: L4.1.15-2.0.0
• Supported carrier boards: AxelEVB-Lite on Dacu, SBCX

Notes

New MVM must be installed for using XELK-3.0.1. The VM is available for download on DAVE's XELK Reserved Area for registered users.

• Major change to NXP BSP 4.1.15
• Updated u-boot and kernel versions
• Updated Yocto version
• Updated Qt version

XELK 2.3.1

• Release date: 18/10/2016
• Status: released
• Freescale Linux BSP: L3.10.17-1.0.3
• Supported carrier boards: SBCX

Notes

It's highly recommended to read the ConfigID and UniqueID page.

• Added support for other ConfigID splash screen on u-boot
• Added support for other ConfigID on linux with related device-tree source code and binaries
• Bug fixes and minor changes

XELK 2.2.0

• Release date: 03/02/2016
• Status: released
• Freescale Linux BSP: L3.10.17-1.0.3
• Supported carrier boards: AxelEVB-Lite on Dacu, SBCX

Notes

It's highly recommended to read the ConfigID and UniqueID page.

• Added splash screen support in U-Boot
• Added support for SBCX carrier board
• Updated u-boot and kernel versions
• Bug fixes and minor changes

Known Limitations

The following table reports the known limitations of this XELK release:

Issue	Description
USB OTG	Verified in Host and Device modes
Reboot from software (not on SBC AXEL)	Rebooting the system from software (eg: launching the reboot command from Linux user space) can lead to a system lock. To solve it, reset the board with the dedicated button (S10). SBC AXEL is not affected by this issue.
Ethernet	10 Mbps connections have not been tested

XELK 2.1.0

• Release date: 04/05/2015
• Status: released
• Freescale Linux BSP: L3.10.17-1.0.0
• Supported carrier boards: AxelEVB-Lite on Dacu

Notes

It's highly recommended to read the ConfigID and UniqueID page.

• Updated u-boot and kernel versions
• Bug fixes and minor changes

Known Limitations

The following table reports the known limitations of this XELK release:

Issue	Description
USB OTG	Verified in Host and Device modes
Reboot from software	Rebooting the system from software (eg: launching the reboot command from Linux user space) can lead to a system lock. To solve it, reset the board with the dedicated button (S10)
Ethernet	10 Mbps connections have not been tested

XELK 2.0.0

• Release date: 26/11/2014
• Status: released
• Freescale Linux BSP: L3.10.17-1.0.0
• Supported carrier boards: AxelEVB-Lite on Dacu

Notes

• Added support for Yocto 1.5
• Updated u-boot and kernel versions
• Bug fixes and minor changes

Known Limitations

The following table reports the known limitations of this XELK release:

Issue	Description
ETH0 interface	On AxelEVB-Lite, there is a mistake in the connection of the center tap pins. They should be separated from one another and connected through separate 0.1μF common-mode capacitors to ground (for further details (eg: connection and selection of the magnetics), please refer to the Micrel KSZ9031RNX datasheet).
USB OTG	Verified in Host and Device modes
Reboot from software	Rebooting the system from software (eg: launching the reboot command from Linux user space) can lead to a system lock. To solve it, reset the board with the dedicated button (S10)
Ethernet	10 Mbps connections have not been tested

XELK 1.2.0

• Release date: 20/05/2014
• Status: released
• Freescale Linux BSP: L3.0.35-4.1.0
• Supported carrier boards: AxelEVB-Lite on Dacu

Notes

• Added support for Axel Lite SOM
• Bug fixes and minor changes

Known Limitations

The following table reports the known limitations of this XELK release:

Issue	Description
USB OTG	Verified in Host and Device modes
SD1	SD1 interface (available on the Axel Lite adapter board as microSD connector) detects the card only if it is inserted before booting Linux
Reboot from software	Rebooting the system from software (eg: launching the reboot command from Linux user space) can lead to a system lock. To solve it, reset the board with the dedicated button (S10)
Ethernet	10 Mbps connections have not been tested

XELK 1.1.0

• Release date: January, 29th 2014
• Status: released
• Freescale Linux BSP: L3.0.35-4.1.0
• Supported carrier boards: AxelEVB-Lite on Dacu

Notes

• Minor update that adds support for more peripherals: nand, rtc, i2c, spi
• Touch screen works properly
• CAN works @ 1Mbps
• The system can boot from SD

Known Limitations

The following table reports the known limitations of this XELK release:

Issue	Description
Boot modes	This kit version supports boot from USB (for recovery purpose), from SPI nor flash and from SD card. Boot from NAND flash will be available on a future release.
CPU cores	Max 2 cores. 3rd and 4th cores will be available on a future release.
USB OTG	Verified in Host and Device modes
Reboot from software	Rebooting the system from software (eg: launching the reboot command from Linux user space) can lead to a system lock. To solve it, reset the board with the dedicated button (S10)
Ethernet	Verified speeds: 1 Gbps and 100 Mbps

XELK 1.0.0

• Release date: November, 4th 2013
• Status: released
• Freescale Linux BSP: L3.0.35-4.1.0
• Supported carrier boards: AxelEVB-Lite on Dacu

Notes

• First official release

Known Limitations

The following table reports the known limitations of this XELK release:

Issue	Description
Boot modes	This kit version supports boot from USB (for recovery purpose) and from SPI nor flash. Other boot devices (MicroSD, NAND flash, ..) will be available on a future release.
CPU cores	Max 2 cores. 3rd and 4th cores will be available on a future release.
USB OTG	Verified in Host and Device modes
Reboot from software	Rebooting the system from software (eg: launching the reboot command from Linux user space) can lead to a system lock. To solve it, reset the board with the dedicated button (S10)
Ethernet	Verified speeds: 1 Gbps and 100 Mbps
CAN	Maximum supported speed: 500 kbps
Touch controller	Touch events are detected, but touch point is not resolved with precision

Quick start guide

This chapter describes how to quickly start working with the XELK kit. The following paragraphs will guide you through the setup and installation procedures.

Kit registration

Customers are strongly recommended to register their kits. Registration grants access to reserved material such as source code and additional documentation.

To register the kit, please send an email to support-axel@dave.eu, providing the kit P/N and S/N.

If you also wish to access git repositories containing source code, please follow the procedure described here.

Target setup and first boot

This section describes how to quick start the AxelEVB board delivered along with XELK kit (see also the following image). The hardware setup is the same for AxelUltra and AxelLite SOMs.

Axel Ultra/AxelEVB setup

The microSD provided with the XELK can be used to boot the system, since it contains a bootable partition (mmcblk0p1) and a root file system partition (mmcblk0p2).

1. Insert the MicroSD card provided with the development kit into the microSD slot
2. Connect the 12V power supply to the JP2 socket on the DACU board
3. (optional) To access the serial console:
   • Connect a serial cable between the J251 connector on the DACU board and PC COM port through a null-modem (https://en.wikipedia.org/wiki/Null_modem) cable (not provided)
   • Start your favorite terminal software on hist side; communication parameters are:
     • Baud rate: 115200 Bps
     • Data bits: 8
     • Stop bits: 1
     • Parity: none
4. (optional) To connect the system to Ethernet LAN, please plug cable on connector J6 connector of the AXELEVB-Lite

By default, the system is configured to boot automatically from the microSD card when powered up.

Binary images on SD card

XELK SD card contains all binary images required for booting the system completely from kernel/dtb (stored on first SD fat card partition) to ext3 root file system (stored on second SD card partition).

Once you got the new binaries compiled from your modified sources, they have to be installed on first SD partition preserving the original file names used into boot.scr u-boot bootscript.

Otherwise, you may create a new boot.scr file using different file names. Here below there is an example on how to create a boot.scr file for booting from SD card:

The bootscript.txt is the text version of the boot.scr file:

echo 'bootscript generated with command "mkimage -A ARM -T script -C none -n XELK -d bootscript.txt boot.scr"'

setenv fdtfile imx6q-xelk-l.dtb
setenv bootfile uImage

setenv mmc_loadk 'fatload mmc ${mmcdev}:1 ${loadaddr} ${bootfile}'
setenv mmc_loadfdt 'fatload mmc ${mmcdev}:1 ${fdtaddr} ${fdtfile}'
setenv mmcboot 'run mmc_loadk mmc_loadfdt mmcargs addip addcons addmisc adddisp0; bootm ${loadaddr} - ${fdtaddr}'

echo Booting AxelLite-XELK via mmcboot

run mmcboot

echo mmcboot FAILURE

and compile it using:

mkimage -A ARM -T script -C none -n XELK -d bootscript.txt boot.scr

Then copy the kernel, dtb and boot.scr into the SD card first partion (the FAT one) and boot XELK with the new images.

Related Documents

• AXEL ULTRA
• AXEL LITE
• AxelEVB-Lite
• Axel FAQs
• Axel Ultra Hardware Manual
• Axel Lite Hardware Manual
• Dacu category page
• Dacu carrier board
• Dacu for the Axel SOM