VAR-SOM-MX6 Android L5.1.1 2.1.0 R1

From Variscite Wiki
VAR-SOM-MX6_Android L5.1.1_2.1.0 R1 developer guide


This WIKI describes how to build and deploy Android Lollipop on the VAR-SOM-MX6. It is based on NXP's Android-ll_511_210 release


The objective of this document is to guide VAR-SOM-MX6 Android developers to obtain Android Lollipop sources, setting up host environment, compilation and deployment.

This document contains instructions for:

  • Hardware and software requirements.
  • Setup the hardware.
  • Setup the toolchain.
  • Download & build the sources.
  • Install the binaries on the VAR-SOM-MX6 SOM and SOM-SOLO/SOM-DUAL SOM.

Supported hardware and features

SOM support
Carrier Board support

i.MX6 Quad
i.MX6 Dual
i.MX6 Dual lite
i.MX6 Solo

NAND Flash size support
128MB and up
up to 64GB
DDR size support configuration
Solo:up to 1GB. DualLite, Dual, Quad: up to 4GB
Wired Network
10/100/1000 Mbps Ethernet
Wireless Network
Support for Wilink8, 802.11abgn STA, AP, & Wi-Fi Direct Mode SmartConfig Wilink8 page
USB host
Host and Device
x3, up to 3.6 Mbps.
Display HDMI: 720P,1080P
LVDS0 (On board LVDS-to-RGB bridge, 800x480 resolution), LVDS1 external display
Audio Line IN/ Line out and Audio over HDMI
Camera ov5640 camera sensor. CB402 board can be ordered separately at :

Hardware Requirements

VAR-SOM-MX6 evaluation kit.

Host (PC) setup requirements

The host development environment for Android is based on Ubuntu, please install Ubuntu version 14.04 64bit LTS

Note: Do not use other Ubuntu releases, than recommended above.

Install required packages on host PC

$ sudo apt-get -y install git-core gnupg flex bison gperf build-essential zip curl zlib1g-dev gcc-multilib g++-multilib libc6-dev-i386 lib32ncurses5-dev x11proto-core-dev libx11-dev lib32z-dev ccache libgl1-mesa-dev libxml2-utils xsltproc unzip mtd-utils u-boot-tools lzop liblzo2-2 liblzo2-dev zlib1g-dev liblz-dev uuid uuid-dev

Install the OpenJDK

sudo apt-get update
sudo apt-get install openjdk-7-jdk

Update the default Java version by running:

sudo update-alternatives --config java
sudo update-alternatives --config javac

The build machine should have at least 50GB of free space to complete the build process.

Obtain source code

Variscite's U-Boot, Linux kernel and Android patches are available through Github.
Required NXP patches for the Android file system are under: in Variscite's FTP


  • IMX6_L5.1_2.1.0_AND_SOURCE_BSP.tar.gz - NXP's i.MX6 LL5.1.1 original BSP patch files.

Unpack NXP's Android Release Package

mkdir ~/var_ll_511_210
cd ~/var_ll_511_210
tar xvf ~/Downloads/IMX6_L5.1_2.1.0_AND_SOURCE_BSP.tar.gz
cd android_L5.1.1_2.1.0-ga_core_source/code/
tar xvf L5.1.1_2.1.0-ga.tar.gz

Download Google Android LL5.1.1

cd ~/var_ll_511_210
mkdir ll_511_210_build
cd ll_511_210_build
mkdir ~/bin
curl > ~/bin/repo
chmod a+x ~/bin/repo
export PATH=~/bin:$PATH
repo init -u -b android-5.1.1_r1 
repo sync
cd ~/var_ll_511_210/ll_511_210_build/prebuilts/gcc/linux-x86/arm
git clone
cd arm-eabi-4.6
git checkout -b android-4.4.3_r1 android-4.4.3_r1

Clone Variscite's U-Boot and Linux kernel sources

cd ~/var_ll_511_210/ll_511_210_build/bootable/bootloader
git clone uboot-imx
cd uboot-imx
git checkout -b imx_v2015.04_3.14.52_1.1.0_ga_var01 remotes/origin/imx_v2015.04_3.14.52_1.1.0_ga_var01
cd ~/var_ll_511_210/ll_511_210_build
git clone kernel_imx
cd kernel_imx
git checkout -b l5.1.1_2.1.0-ga_var01 remotes/origin/l5.1.1_2.1.0-ga_var01

Apply all the i.MX Android patches with Freescale i.MX6 support

cd ~/var_ll_511_210/ll_511_210_build
source  ../android_L5.1.1_2.1.0-ga_core_source/code/L5.1.1_2.1.0-ga/
You should see that the "c_patch" function is available.
c_patch  ../android_L5.1.1_2.1.0-ga_core_source/code/L5.1.1_2.1.0-ga imx_L5.1.1_2.1.0-ga
If everything is OK, "c_patch" generates the following output to indicate the successful patch:
Success: Now you can build the Android code for FSL i.MX platform

Apply Variscite's i.MX6 platforms' patches

cd ~/var_ll_511_210/ll_511_210_build/device
git clone -b l5.1.1_2.1.0_var01 variscite

Build Android Images

Change to Android top level directory.

cd ~/var_ll_511_210/ll_511_210_build
source build/
lunch var_mx6-user
lunch var_mx6-eng
var_mx6-user creates a production version of the Android Lollipop.

var_mx6-eng creates an engineering version of the Android Lollipop. Development mode enable and development tools are available on target.

Switching from eMMC build to SD card build and vice versa

When you switch your target MMC device you need to remove the fstab file. This will guarantee that the make system will copy the right one into target.

rm out/target/product/var_mx6/root/fstab.freescale

Build Android for SD card

make -j4 BUILD_TARGET_DEVICE=sd 2>&1 | tee build1-1.log

Build Android for on-SOM eMMC

make -j4 BUILD_TARGET_DEVICE=emmc 2>&1 | tee build1-1.log

Build for NAND

NOTE: Due to android file system size, Android should use SD-Card or eMMC only.

Images created by the Android build for Variscite MX6 system

If you do ls out/target/product/var_mx6/

system.img Android system image file.
SOM agnostics.
u-boot-var-imx6-nand.img u-boot for nand used in eMMC boot.
SOM agnostics.
u-boot-var-imx6-sd.img u-boot for SD card boot.
SOM agnostics.
<name> is one of: som-mx6q - Supports VAR-SOM-MX6Q and VAR-SOM-MX6D
som-mx6dl - Supports VAR-SOM-MX6DL and VAR-SOM-MX6S
som-solo - Supports VAR-SOM-SOLO and VAR-SOM-DUAL
<touch> - is "r" or "c" r = resistive touch display
c = capacitive touch dispaly
Image Name
SOM type
Carrier Board type
LCD Type
Evaluation Kit name
boot-som-mx6q-c.img, recovery-som-mx6q-c.img VAR-SOM-MX6_V2 (Quad / Dual) VAR-MX6CustomBoard Capacitive touch VAR-DVK-MX6_V2-PRO
boot-som-mx6q-r.img, recovery-som-mx6q-r.img VAR-SOM-MX6_V2 (Quad / Dual) VAR-MX6CustomBoard Resistive touch VAR-DVK-MX6_V2
boot-som-mx6q-vsc.img, recovery-som-mx6q-vsc.img VAR-SOM-MX6_V2 (Quad / Dual) VAR-SOLOCustomBoard Capacitive LVDS touch N/A
boot-som-mx6dl-c.img, recovery-som-mx6dl-c.img VAR-SOM-MX6_V2 (DualLite/ Solo) VAR-MX6CustomBoard Capacitive touch N/A
boot-som-mx6dl-r.img, recovery-som-mx6dl-r.img VAR-SOM-MX6_V2 (DualLite/ Solo) VAR-MX6CustomBoard Resistive touch N/A
boot-som-solo-vsc.img, recovery-som-solo-vsc.img VAR-SOM-SOLO / VAR-SOM-DUAL VAR-SOLOCustomBoard Capacitive LVDS touch VAR-DVK-SOLO/DUAL
boot-som-solo-c.img, recovery-som-solo-c.img VAR-SOM-SOLO / VAR-SOM-DUAL VAR-MX6CustomBoard Capacitive touch N/A
boot-imx6q-var-dart.img, recovery-imx6q-var-dart.img DART-MX6 VAR-DT6CustomBoard Capacitive touch VAR-STK-DT6

Boot options

Boot options of the Android:
1. Directly from SD-Card
2. Uboot boots from NAND flash, and the rest of the Android images from on-SOM eMMC (when available)

Flash and boot Android from SD card

Create a bootable SD card

cd ~/var_ll_511_210/ll_511_210_build
cp device/variscite/common/tools/ .

Partition, format and copy all images to an SD card:

sudo ./ -f <name>-<touch> /dev/sdX; sync
  • See the possible <name> and <touch> values at the above table
  • Replace /dev/sdX with your true device, You can identify it with dmesg

Boot From SD card

After following the above steps for creating a bootable SD card:

  • Power-off board
  • Insert the newly created SD card into the SD card socket of the evaluation kit.
  • Press and hold the boot-select button, and power-on the kit.

Flash and boot Android from eMMC

eMMC based system consist of:

  1. SPL and U-boot on NAND-Flash
  2. Rest of Android images in eMMC

Preparing images

All Android built images but system.img are ready for flashing out of the default build.
system.img must be modified:

cd out/target/product/var_mx6
simg2img system.img system_raw.img
rm system.img
mv system_raw.img system.img

Step is required only for eMMC binaries.

Flashing Android from Linux shell

An example of flashing the various images into NAND flash and eMMC, can be found here :
You can use this pre-built recovery SD-Card, replace your newly created images with the ones in the /media/rootfs/opt/images/Android/Emmc directory, and run the script
also refer to for details

Flashing Android with USB Fastboot

Make sure you built Android for emmc

Connect the target with host PC at fastboot mode:

  1. Connect a USB OTG cable from the target board OTG port to a your host machine USB HOST port.
  2. Power up the board and hit return/space to stop the boot at u-boot
  3. type fastboot in the u-boot prompt.

In case you already have partitions on the eMMC you can skip the next step.

$ sudo `which fastboot` flash mbr  emmc_mbr.img

The mbr need to be collected once of an eMMC formatted target. You can install the eMMC for the fisrt time by using our nand-recovery utility.

$ dd if=/dev/mmcblk1 of=emmc_mbr.img bs=512 count=1
If you write the MBR reset the board and enter again to fastboot before you try to flash the other images.

On the Host PC:

$ sudo `which fastboot` flash boot out/target/product/var_mx6/boot-som-mx6q-c.img
$ sudo `which fastboot` flash recovery out/target/product/var_mx6/recovery-som-mx6q-c.img
$ sudo `which fastboot` flash system out/target/product/var_mx6/system.img
$ sudo `which fastboot` reboot

boot-som-mx6q-c.img and recovery-som-mx6q-c.img are for VAR-SOM-MX6 with a capacitive display. You should pick and choose the right file for you see the table above.

Manual operations

Build boot.img

When you perform changes to the kernel, you may build boot.img solely instead of building the whole Android.

cd ~/var_ll_511_210/ll_511_210_build
source build/
lunch var_mx6-user
make bootimage

Toolchain setup for manual build kernel and U-Boot

Setup the toolchain path to point to arm-eabi- tools in prebuilts/gcc/linux-x86/arm/arm-eabi-4.6/bin

export ARCH=arm
export PATH=~/var_ll_511_210/ll_511_210_build/prebuilts/gcc/linux-x86/arm/arm-eabi-4.6/bin:$PATH
export CROSS_COMPILE=arm-eabi-

Manual build Bootloader 

Change directory to u-boot

cd ~/var_ll_511_210/ll_511_210_build/bootable/bootloader/uboot-imx

Execute following commands:

clean tree:
$ make mrproper

Choose build for SD card or NAND Flash:
$ make mx6var_som_sd_android_defconfig
$ make mx6var_som_nand_android_defconfig

Build U-Boot:
$ make -j4

This command will generate the U-Boot images 'SPL' and 'u-boot.img'.

Manual build Android Linux Kernel and modules

cd ~/var_ll_511_210/ll_511_210_build/kernel_imx 
make distclean
make imx_v7_var_android_defconfig
make -j4 uImage LOADADDR=0x10008000
make -j4 modules

This will generate uImage(kernel image) in kernel/arch/arm/boot folder

Display Options

Selecting the display type is done by setting the bootcmd with the required display type.

The bootcmd is embedded into boot.img. To set the bootargs edit the file ~/var_ll_511_210/ll_511_210_build/device/variscite/var_som_mx6/ as follows:

  • HDMI
BOARD_KERNEL_CMDLINE := console=ttymxc0,115200 init=/init video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24,bpp=32 video=mxcfb1:off video=mxcfb2:off video=mxcfb3:off vmalloc=400M androidboot.console=ttymxc0 consoleblank=0 androidboot.hardware=freescale cma=384M androidboot.selinux=disabled androidboot.dm_verity=disabled