OEM Image Setup

This article shows how OEMs can create images including custom applications and settings

Linux

Prerequisites：

Android-tools：https://developer.android.com/studio/releases/platform-tools

Step

• Download and unzip following files:

• simg2img](https://herelinkfw.cubepilot.org/tools/simg2img_linux.zip)

• img2simg](https://herelinkfw.cubepilot.org/tools/img2simg_linux.zip)

• Remote Unit: oem_ru_base.img

• Air Unit: oem_au_base.img

• Ensure that you select the base image depending upon which unit you are modifying.

• Download and extract zips into same directory.

• Now to generate ext4fs image from the sparse image (.img) downloaded above do ./simg2img_mac oem_au_base.img raw_oem_au_base.img

• Create a mount point directory using mkdir oem

• Mount the image using mount raw_oem_au_base.img oem

• Now you should be able to modify files inside the mount directory.

• You need to use sudo to be able to do any writes the files inside the mount point.

• Once you have made your changes, you need to unmount your drive using command sudo umount oem

• Afterwards convert the ext4fs image back to android sparse image using command ./img2simg raw_oem_au_base.img oem_au.img

• Now you may flash this image into Herelink Air Unit, by putting it under bootloader using command adb reboot bootloader

• And finally to flash to image run command fastboot flash oem oem_au.img

• Check example below for a sample modification.

MacOS

Prerequisites：

Homebrew：https://brew.sh/

Android：https://developer.android.com/studio/releases/platform-tools

Step

• Setup osxfuse in your system using brew cask install osxfuse, this will require rebooting your system proceed and do that。

• Follow the steps here to install fuse-ext2. This will allow you to mount ext4fs we will be generating.

  https://github.com/alperakcan/fuse-ext2#macos

• Download and unzip following files:

  • simg2img：https://herelinkfw.cubepilot.org/tools/simg2img_mac.zip

  • img2simg：https://herelinkfw.cubepilot.org/tools/img2simg_mac.zip

  • Remote Unit：https://herelinkfw.cubepilot.org/tools/oem_ru_base.img

  • Air Unit：https://herelinkfw.cubepilot.org/tools/oem_au_base.img

• Ensure that you select the base image depending upon which unit you are modifying.

• Download and extract zips into same directory.

• Now to generate ext4fs image from the sparse image (.img) downloaded above do

  ./simg2img_mac oem_au_base.img raw_oem_au_base.img

• Create a mount point directory using

  mkdir oem

• Mount the image using

• fuse-ext2 raw_oem_au_base.img oem -o rw+

• Now you should be able to modify files inside the mount directory.

• You need to use sudo to be able to do any writes the files inside the mount point.

• Once you have made your changes, you need to unmount your drive using command

  sudo umount oem

• Afterwards convert the ext4fs image back to android sparse image using command

  ./img2simg raw_oem_au_base.img oem_au.img

• Now you may flash this image into Herelink Air Unit, by putting it under bootloader using command

adb reboot bootloader

• And finally to flash to image run command：

  fastboot flash oem oem_au.img

Example：

• In the following example we change the system_id used by herelink air unit for board specific messages.

• Most config files are located in you unit at /system/etcin the following example we will pull config using command adb pull /system/etc/system-control.telepathy-air.conf

• Once pulled the file will contain information like bellow:

# module on/off

board_control_enabled = true

d2d_tracker_enabled = true

camera_control_enabled = true

# board control

board_system_id = 42

# camera control

video_stream_ip_address = 192.168.0.10

camera_system_id = 42

support_multiple_camera = true

support_camera_capture = false

• You can change the value of board_system_id and camera_system_id fields as per your requirement in your favourite editor.

• Once done save this file and exit editor.

• Create a folder inside oem image called etc using command sudo mkdir oem/etc

• Copy file using command sudo cp system-control.telepathy-air.conf oem/etc/

• Continue to unmount the image and flashing into the unit as described in above steps.

Example App Change

• In the following example we override the installed QGroundcontrol App.

• A new OEM app can be installed under /oem/app//.apk

• For installing your custom version of QGroundcontrol, ensure that you started with https://github.com/cubepilot/qgroundcontrol-herelink as your base.

• After building the project, create a folder QgroundControl

• Copy .apk file cp -r build-qgroundcontrol-Android_for_armeabi_v7a_Clang_Qt_5_11_0_for_Android_armv72_fd6ff4-Debug/android-build/build/outputs/apk/android-build-debug.apk QGroundControl/QGroundControl.apk

• Also create a lib directory QGroundControl/lib

• Copy libraries cp -r build-qgroundcontrol-Android_for_armeabi_v7a_Clang_Qt_5_11_0_for_Android_armv72_fd6ff4-Debug/android-build/libs/armeabi-v7a/ QGroundControl/lib/arm/

• Finally move QgroundControl directory to oem image sudo cp -r QGroundControl oem/app/QGroundControl

• Do ensure you have already created app directory inside oem image if not already done sudo mkdir oem/app

• Continue to unmount the image and flashing into the unit as described in above steps.

Extra OEM Files：

• On boot several files are setup for use, and you can override these files

• These files can exist in (searched in this order)

/data/oem/etc - user default - wiped on factory reset

/oem/etc - oem default

/system/etc - system default

• files that can be overridden (optimus is the internal GCS name, telepathy-air is the air unit (ro.product.device))

lampsignal-telepathy-air.json

rc_service_config_optimus.ini

mavlink-router.optimus.conf

system-control.optimus.conf