DART-6UL Yocto Jethro R1 build

From Variscite Wiki
DART-6UL - Yocto fsl-4.1.15 Yocto Jethro R1 Build

Installing required packages

Follow the link below and install all required packages on your machine.


Please make sure you host PC is running Ubuntu 14.04 and install the following packages:

sudo apt-get install gawk wget git-core diffstat unzip texinfo gcc-multilib build-essential chrpath socat libsdl1.2-dev
sudo apt-get install autoconf libtool libglib2.0-dev libarchive-dev
sudo apt-get install python-git xterm sed cvs subversion coreutils texi2html
sudo apt-get install docbook-utils python-pysqlite2 help2man make gcc g++ desktop-file-utils libgl1-mesa-dev
sudo apt-get install libglu1-mesa-dev mercurial automake groff curl lzop asciidoc u-boot-tools mtd-utils


Documentation are available for Download from FreescaleJethroDocuments

Download Yocto Jethro for i.MX6UL Freescale source

$ git config --global user.name "Your Name"
$ git config --global user.email "Your Email"

$ mkdir ~/bin (this step may not be needed if the bin folder already exists)
$ curl http://commondatastorage.googleapis.com/git-repo-downloads/repo > ~/bin/repo
$ chmod a+x ~/bin/repo
$ export PATH=~/bin:$PATH

$ mkdir ~/var-mx6ul-mx7-yocto-jethro
$ cd ~/var-mx6ul-mx7-yocto-jethro
$ repo init -u git://git.freescale.com/imx/fsl-arm-yocto-bsp.git -b imx-4.1.15-1.0.0_ga
$ repo sync

Download Yocto Jethro i.MX6UL with Meta Variscite DART-6UL support

$ cd ~/var-mx6ul-mx7-yocto-jethro/sources
$ git clone https://github.com/varigit/meta-variscite-mx6ul-mx7/ -b imx_4.1.15_ga-var01
$ cp meta-variscite-mx6ul-mx7/scripts/var-setup-release.sh ../
$ patch -p1 < meta-variscite-mx6ul-mx7/patch/Fix-FSL-multi-patch-append-bugs.patch

Setup and build Yocto

The following images can be built:

  • fsl-imx-x11 - Only X11 graphics
  • fsl-imx-wayland - Wayland weston graphics
  • fsl-imx-xwayland - Wayland graphics and X11. X11 applications using EGL are not supported
  • fsl-imx-fb - Frame Buffer graphics - no X11 or Wayland

Note: refer to ftp://customerv:Variscite1@ftp.variscite.com/VAR-SOM-MX6/Software/Linux/Yocto/fsl-yocto-imx-4.1.15_1.0.0-docs/Freescale_Yocto_Project_User's_Guide.pdf
Page 7 for further information.

Sample build scenarios:

Build X11 GUI image without Qt content

$ cd ~/var-mx6ul-mx7-yocto-jethro
$ MACHINE=imx6ul-var-dart DISTRO=fsl-imx-x11 source var-setup-release.sh -b build_x11

Optional: Direct downloads to /opt/yocto_downloads, make sure directory exists and all permissions are set

$ sudo mkdir /opt/yocto_downloads
$ sudo chmod 777 /opt/yocto_downloads/
$ sed -i 's/DL_DIR ?= "${BSPDIR}\/downloads/DL_DIR = "\/opt\/yocto_downloads/g' conf/local.conf

launch bitbake:

$ bitbake fsl-image-gui

Build opensource QT5 image

$ cd ~/var-mx6ul-mx7-yocto-jethro
$ MACHINE=imx6ul-var-dart DISTRO=fsl-imx-fb source var-setup-release.sh -b build-fb

Optional: Direct downloads to /opt/yocto_downloads, make sure directory exists and all permissions are set

sed -i 's/DL_DIR ?= "${BSPDIR}\/downloads/DL_DIR = "\/opt\/yocto_downloads/g' conf/local.conf

launch bitbake:

$ bitbake fsl-image-qt5

Build Results

The resulted images are located in tmp/deploy/images/imx6ul-var-dart/.
Looking at tmp/deploy/images/imx6ul-var-dart/ you will find 6 main files that are linked to the actual file

Image Name
How to use
Not in Use
fsl-image-gui-imx6ul-var-dart.sdcard This image is for SD card boot.
It can be flashed as-is on an SD card and you can boot your system
form SD card, according to the relevant startup-guide of your product (usually requires to press the boot select button, or toggle a dip-switch).

For detailed information refer to Create a sample SD card section below Create a bootable SD card.

fsl-image-gui-imx6ul-var-dart.tar.bz2 Used to create an NFS root file system on the host. See apendix for setting an NFS server
fsl-image-gui-imx6ul-var-dart.ubi Use the SD card created above. Copy the file into it and use the following commands to flash them into NAND.
Coping files (mount the SD card created above first):
zImage Linux kernel image
SPL-nand SPL built for NAND flash. The SPL is a pre-U-Boot SW component, required for DDR initialization
SPL-sd SPL built for SD card boot. The SPL is pre-U-Boot SW component, required for DDR initialization
u-boot.img-sd U-Boot built for SD card boot, or eMMC boot
u-boot.img-nand U-Boot built for NAND flash boot
Device Tree Name
Boot Device
zImage-imx6ul-var-dart-emmc_wifi.dtb Boot from internal eMMC with WI-FI enabled. (SD card & NAND disabled)
zImage-imx6ul-var-dart-nand_wifi.dtb Boot from internal NAND with WI-FI enabled. (SD card & eMMC disabled)
zImage-imx6ul-var-dart-sd_emmc.dtb SD card and eMMC enabled (WIFI & NAND disabled). You can boot from eMMC or SD card
zImage-imx6ul-var-dart-sd_nand.dtb SD card and NAND enabled (WIFI & eMMC disabled). You can boot from NAND or SD card

Create a bootable SD card

SD card structure

The first unallocated 4MB are saved space for U-Boot. it can be replaced with a dd command described in "U-Boot out of tree" section below.
The first partition is a fat16 partition used for the Linux uImage and device tree files. You can copy them as described in the Linux out of tree section.
The second partition is an ext4 partition that contains the complete file system and modules.

Yocto pre-built bootable SD card

The Yocto build products contains many files as explained in Build Results section above including a ".sdcard" file. For example fsl-image-gui-imx6ul-var-dart.sdcard. This is a complete image to be flashed directly to an SD card.
Example usage:

$ cd ~/var-mx6ul-mx7-yocto-jethro/build_x11
$ sudo dd if=tmp/deploy/images/imx6ul-var-dart/fsl-image-gui-imx6ul-var-dart.sdcard of=/dev/sdX bs=1M
Replace sdX with the right device name.

Drawbacks of the native .sdcard yocto-built image:

  • The second partition size doesn't use the entire SD card.
  • The second partition is not labeled as rootfs.
  • The NAND and eMMC flashing scripts are not included.

Create an extended SD card

Variscite provides var-create-yocto-sdcard.sh script that makes use of the .sdcard image mentioned above, extends the partitions of the SD card to the maximum available space, and copies the NAND flash burning scripts and relevant binaries for your convenience.
Later, you will be able to follow DART-6UL NAND Flash Burning do burn your images to NAND flash or eMMC
See usage below:

$ cd ~/var-mx6ul-mx7-yocto-jethro/build_x11
$ sudo ../sources/meta-variscite-mx6ul-mx7/scripts/var_mk_yocto_sdcard/var-create-yocto-sdcard.sh /dev/sdX
Replace sdX with the right device name.

The script assume fsl-image-qt5-minimal build was used. It is very easy to modify it and adopt it to your requirements.

Boot board with a bootable SD card

Note: Boot from SD card eliminates Wifi as the Wifi and SD card are using same SDIO interface.
A typical use-case, is to boot from SD card, flash eMMC or NAND flash, and re-boot form eMMC/NAND to have Wi-Fi operational.

Setting board dip-switches

Booting your system requires switching the relevant dip-switch to "Boot from SD card". See picture below.

Boot switch 6ul1.jpg

  • "00" - Boot from SD card - The picture mode
  • "01" - Boot from eMMC
  • "10" - Boot from NAND flash
  • "11" is illegal.

Be aware that your SOM has either eMMC or NAND, but never both!

To boot board with SD card, Follow the steps below:

  • Power-off the board.
  • Insert the SD card into the SD/MMC slot of the carrier board (DVK)
  • Switch the relevant dip-switch to "Boot from SD card"
  • Power-up board
  • The board will automatically boot into Linux from SD card

Automatic device Tree selection in U-Boot

Upon reset you will see the U-Boot SPL printouts. It will print also the SOM configuration:
On-SOM storage: SD only, eMMC, NAND.
WIFI if chip exits.
For example:

U-Boot SPL 2015.10-00532-g482dc88 (Jan 03 2016 - 10:05:42)
Part number: DART-6U-A01
Assembly: AS11
Date of production: 2015 Dec 31
DART-6UL configuration: eMMC WIFI
Ram size: 512
Boot Device: SD

As explained in the above Build Results table we have 4 optional configurations.
We implemented in U-Boot and automatic device tree selection, so when kernel boots, the U-Boot will load the corresponding device tree according to On-SOM configuration.

Boot From
SOM Internal FLASH
Device Tree selected
SD eMMC Don't Care imx6ul-var-dart-sd_emmc.dtb
SD NAND Don't Care imx6ul-var-dart-sd_nand.dtb
eMMC eMMC Yes imx6ul-var-dart-emmc_wifi.dtb
eMMC eMMC NO imx6ul-var-dart-sd_emmc.dtb
NAND NAND YES imx6ul-var-dart-nand_wifi.dtb
NAND NAND NO imx6ul-var-dart-sd_nand.dtb

Note: Boot from SD card eliminates Wifi as the Wifi and SD card are using same SDIO interface.
A typical use-case, is to boot from SD card, flash eMMC or NAND flash, and re-boot form eMMC/NAND to have Wi-Fi operational.

Disable Automatic Device Tree selection

To disable the automatic device tree selection in U-Boot:

$ setenv var_auto_fdt_file=N
$ saveenv

Now you can set the device tree to meet your requirments. For example:

$ setenv fdt_file=imx6ul-var-dart-sd_emmc.dtb
$ saveenv

Will select device tree that has SD and eMMC regardless if the SOM has WIFI.

$ setenv fdt_file=imx6ul-var-dart-sd_nand.dtb
$ saveenv

Will select device tree that has SD and NAND regardless if the SOM has WIFI.

Make sure you don't set am illegal value like "imx6ul-var-dart-sd_nand.dtb" in a SOM that has eMMC flash.

Flash images to NAND/eMMC

Please refer to DART-6UL NAND Flash Burning

QT5/Embedded runtime

Environment Variables

The QT5/Embedded require environment variables to run correctly. DART6Ul support QT Embedded over Linux Frame Buffer. For example /etc/profile.d/tslib.sh can be edited. The following example enable touch, mouse and keyboard:

export TSLIB_TSDEVICE='/dev/input/touchscreen0'
export TSLIB_CALIBFILE='/etc/pointercal'
export TSLIB_CONFFILE='/etc/ts.conf'
export TSLIB_FBDEVICE='/dev/fb0'
export TSLIB_PLUGINDIR='/usr/lib/ts'

export QT_QPA_PLATFORM=linuxfb:fb=/dev/fb0:size=800x480:mmSize=800x480
export QT_QPA_EVDEV_TOUCHSCREEN_PARAMETERS='/dev/input/touchscreen0'
export QT_QPA_GENERIC_PLUGINS='tslib:/dev/input/touchscreen0,evdevmouse:/dev/input/event5,evdevkeyboard:/dev/input/event3'

Running Application

$ cd /usr/share/qt5/examples/
$ touch/dials/dials --platform linuxfb
$ gui/rasterwindow/rasterwindow --platform linuxfb
$ touch/fingerpaint/fingerpaint  --platform linuxfb
$ widgets/mainwindows/mainwindow/mainwindow --platform linuxfb

Next steps

In sections 1-6 we explained how to build Yocto for DART-6UL. We explained the results for NAND (UBI) and for SD card. At this point you should have a bootable SD card with UBI images on it. You should be able to boot from the SD card using the boot select button and flash the NAND. Next steps:

  • Build and deploy the compiler and tools.
  • Fetch U-Boot and compile it out of Yocto tools.
  • Fetch Linux kernel and compile it out of Yocto tools.

Update Yocto Jethro i.MX6UL Meta Variscite DART-6UL support

From time to time we will post updates to meta-variscite-mx6ul-mx7. This will include improve features and bug fix. You can track the history log in the previous page to see if such an update was posted. In such a case follow the instructions below to update your tree.

$ cd ~/var-mx6ul-mx7-yocto-jethro/sources/meta-variscite-mx6ul-mx7/
$ git fetch origin
$ git pull
Set your enviroment
$ cd ~/var-mx6ul-mx7-yocto-jethro
$ MACHINE=imx6ul-var-dart DISTRO=fsl-imx-x11 source var-setup-release.sh -b build_x11
In order to update the kernel
$ bitbake -c cleanall linux-variscite
$ bitbake  -c cleanall u-boot-variscite
and build your image
$ bitbake fsl-image-gui

Useful Bitbake commands

Bitbake Cheat Sheet

Useful bitbake commands

i.MX Yocto Project: ltib versus bitbake