Linaro Releases

The Linaro Qualcomm Landing Team is pleased to announce the new release of the Linaro Linux release for Qualcomm™ Snapdragon® 410 processor. The Linaro Linux release 16.04 is a Debian-based Linaro Build that provides developers with a desktop like environment using Debian and the LXDE desktop, as well as a console-only image.

What’s new in this release

• Upgrade to Debian 8.4.
• Upgrade to Linux kernel 4.4.8
• Added support for Soft AP mode in wcn36xx
• Added SPI_SPIDEV as module, and proper aliases in DTS
• Bug fixed:
  • qcom-lt/release/qcomlt-4.4: panic() during tests after disabling DEBUG_LOCK_ALLOC
  • Provide instructions to create a bootable SD card
  • hwclock doesn’t work

Features

The Linaro Linux version 16.04 for the Snapdragon 410 supports the following features:

• Provides a working Debian environment with access to Debian repositories (apt-get) and updates. It is based on Debian 8.4 (aka jessie).
• It is based on Linux kernel 4.4.8.
• It is based on proprietary firmware available on Qualcomm Developer Network.
• The following images are released:
  • boot image that includes prebuilt kernel and initrd
  • developer image that includes core packages as well as typical development packages (headless)
  • alip image that includes a minimal desktop environment GUI using LXDE
• All images have a pre-configured user called linaro, and the password for this user is set to linaro
• The root file system should be flashed in the onboard eMMC.
• The following features are supported on the DragonBoard 410c:
  • Quad Core ARMv8 A53 CPU (@1.2GHz)
  • Adreno 306 GPU, powered by freedreno Mesa/Gallium GPU driver, version 11.1.2
    • OpenGL 3.1, OpenGLES 3.0, GLX, EGL
    • xf86-video-freedreno driver v1.4.0, with XA support enabled
  • Cpufreq, using ondemand governor by default
  • CPU thermal sensors, and thermal management using the step wise governor
  • HDMI display and audio using the onboard ADV7533 MIPI/DSI Receiver with HDMI Transmitter from Analog Devices
  • UART, SD, eMMC
  • USB2.0 (Mouse, Keyboard, Storage, Ethernet)
  • Wifi and Bluetooth using integrated WCN3620, using proprietary firmware and wcn36xx driver
  • Hardware accelerated video codecs using dedicated Snapdragon coprocessor

Information about the DragonBoard 410c

For more information about the DragonBoard 410c, please check the following website and wiki:

• http://www.96boards.org/dragonboard410c
• http://www.96boards.org/dragonboard410c/documentation
• http://www.96boards.org/dragonboard410c/gettingstarted
• https://github.com/96boards/documentation/wiki
• https://developer.qualcomm.com/hardware/dragonboard-410c

How to install and use this release

To install this release please follow the instructions from the DragonBoard 410c Linux user guide.

Proprietary firmware

This release contains proprietary firmware. You can download the proprietary firmware separately, from here. All the required firmware files are pre-installed, and our images are bound to the following license agreement.

Running the ALIP Desktop image

The ALIP/LXDE image is expected to provide a desktop-like experience, as such it is recommended to use an HDMI monitor, as well as USB keyboard and mouse. The default image will directly boot to the login screen by default. However a root console login will also be started on the serial console.

Note: The default bootargs enable the kernel messages to be displayed on the serial console.

Running the Developer based image

If you have flashed the developer image, when booting the board you will end up in a root login on the serial console. If you have an HDMI monitor connected, you will also have login terminals on the display

How to get and customize the kernel source code

Building the Linux kernel from source

The Linux kernel used in this release is available via tags in the Linaro Qualcomm Landing Team git repository:

git: http://git.linaro.org/landing-teams/working/qualcomm/kernel.git
tag: debian-qcom-dragonboard410c-16.04
defconfig: arch/arm64/defconfig kernel/configs/distro.config

The kernel image (Image) is located in the boot image and partition and the kernel modules are installed in the root file system. It is possible for a user to rebuild the kernel and run a custom kernel image instead of the released kernel. You can build the kernel using any recent GCC release using the git tree, tag and defconfig mentioned above. This release only supports booting with device tree, as such both the device tree blobs need to be built as well.

The DragonBoard 410c is an ARMv8 platform, and the kernel is compiled for the Aarch64 target. Even though it is possible to build natively, on the target board, It is recommended to build the Linux kernel on a PC development host. In which case you need to install a cross compiler for the ARM architecture. It is recommended to download the Linaro GCC cross compiler.

To build the Linux kernel, you can use the following instructions:

git clone -n http://git.linaro.org/landing-teams/working/qualcomm/kernel.git
cd kernel
git checkout -b kernel-16.04 debian-qcom-dragonboard410c-16.04
export ARCH=arm64
export CROSS_COMPILE=<path to your GCC cross compiler>/aarch64-linux-gnu-
make defconfig distro.config
make -j4 Image dtbs KERNELRELEASE=4.4.8-linaro-lt-qcom

Additionally, you might want or need to compile the kernel modules:

make -j4 modules KERNELRELEASE=4.4.8-linaro-lt-qcom

Building a boot image

You now need to create a valid boot image with your own kernel build.

On your host PC, we need to install the following tools:

sudo apt-get install device-tree-compiler
git clone git://codeaurora.org/quic/kernel/skales

The boot image consists of the table of device tree (dt.img), the kernel image (Image) and an init ramdisk image.

The dtbTool is a standalone application that will process the DTBs generated during the kernel build, to create the table of device tree image. This tool is included in the skales git tree cloned above.

./skales/dtbTool -o dt.img -s 2048 arch/arm64/boot/dts/qcom/

To create the boot image, you also need a ramdisk image, and you can use the one from the release:

wget http://builds.96boards.org/releases/dragonboard410c/linaro/debian/16.04/initrd.img-4.4.8-linaro-lt-qcom

The tool mkbootimg (also in the git tree previously cloned) is a standalone application that will process all files and create the boot image that can then be booted on the target board, or flash into the on-board eMMC. The boot image also contains the kernel bootargs, which can be changed as needed in the next command:

./skales/mkbootimg --kernel arch/arm64/boot/Image \
                   --ramdisk initrd.img-4.4.8-linaro-lt-qcom \
                   --output boot-db410c.img \
                   --dt dt.img \
                   --pagesize 2048 \
                   --base 0x80000000 \
                   --cmdline "root=/dev/disk/by-partlabel/rootfs rw rootwait console=ttyMSM0,115200n8"

Booting a custom boot image

Assuming you have now built a valid boot image called boot-db410c.img, you can run the following fastboot command to boot it on the board:

sudo fastboot boot boot-db410c.img

If you want to permanently use a custom kernel image, you can update the boot image and reflash it into the boot partition:

sudo fastboot flash boot boot-db410c.img

How to get and customize the bootloader

While the first stage bootloader is proprietary and released as firmware blob available on Qualcomm Developer Network, the second stage bootloader is LK and is open source.

The original LK source code is available on CodeAurora.org, and the source code which is used in this release can be found in the Linaro Qualcomm Landing Team git repository:

git: http://git.linaro.org/landing-teams/working/qualcomm/lk.git
tag: debian-qcom-dragonboard410c-LA.BR.1.2.4-00310-8x16.0-linaro1

To build the LK bootloader, you can use the following instructions:

git clone git://codeaurora.org/platform/prebuilts/gcc/linux-x86/arm/arm-eabi-4.8.git -b LA.BR.1.1.3.c4-01000-8x16.0
git clone http://git.linaro.org/landing-teams/working/qualcomm/lk.git -b debian-qcom-dragonboard410c-LA.BR.1.2.4-00310-8x16.0-linaro1
cd lk
make -j4 msm8916 EMMC_BOOT=1 TOOLCHAIN_PREFIX=<path to arm-eabi-4.8 tree>/bin/arm-eabi-

The second stage bootloader is flashed on the aboot partition, you can now flash your board with:

sudo fastboot aboot ./build-msm8916/emmc_appsboot.mbn

How to get and customize Debian/Ubuntu packages source code

This release is based on Debian 8.4 (aka jessie), and it is not possible to use a different Debian release (e.g. it is not possible to downgrade to an older Debian release, nor is it possible to use a newer release, such as the one being currently developed).

Since all packages installed in Linaro Debian-based images are maintained either in Debian archives or in Linaro repositories, it is possible for users to update their environment with commands such as:

sudo apt-get update
sudo apt-get upgrade

All user space software is packaged using Ubuntu or Debian packaging process. As such you can find extensive information about using, patching and building packages in the Ubuntu packaging guide or The Debian New Maintainers Guide. If you quickly want to rebuild any package, you can run the following commands to fetch the package source code and install all build dependencies:

sudo apt-get update
sudo apt-get build-dep <pkg>
apt-get source <pkg>

Then you can rebuild the package locally with:

cd <pkg-version>
dpkg-buildpackage -b -us -uc

Notes:

• you can drop patches in debian/patches/ and update debian/patches/series before building with dpkg-buildpackage to customize the source code.
• all associated .deb files will be located in the root folder, and can be installed in the system with dpkg -i .deb.
• all these commands should be executed on the target directly, not on the development host. It is generally enough to build packages natively, on the target platform. For some packages, it is possible to cross compile Ubuntu/Debian packages however this goes beyond the scope of this wiki page.

Using X11 with modesetting video driver and GLAMOR

While not enabled by default, it is possible use evaluate X11/GLAMOR. In order to start X server with the modesetting driver, with GLAMOR support, your first need to make sure that X server is not running:

sudo systemctl stop lightdm

Then you can run the following commands to switch from freedreno video driver, to modesetting, and restart the LXDE desktop:

sudo sed -i 's/freedreno/modesetting/' /usr/share/X11/xorg.conf.d/42-freedreno.conf
sudo systemctl start lightdm

To switch back to freedreno video driver, please run:

sudo systemctl stop lightdm
sudo sed -i 's/modesetting/freedreno/' /usr/share/X11/xorg.conf.d/42-freedreno.conf
sudo systemctl start lightdm

Audio configuration settings

The release has support for both analog and digital audio (HDMI). When using the ALIP desktop image, to switch back and forth you can use PulseAudio volume control application, and in the configuration tab, you will be able to chose which profile to use. Note that by default, PulseAudio will use the analog output, and you need to switch to HDMI at first boot if your HDMI monitor supports HDMI audio.

Feedback and Support

For general question or support request, please go to 96boards.org Community forum.

For any bug related to this release, please submit issues to the 96Board.org Bug tracking system. To submit a bug, follow this link.

Bugs will be reviewed and prioritized by the team. For any bug report it is recommended to provide as much information as possible, and at the very list please include the name of the release you are using, the output of dpkg -l to list all packages installed, as well, as the boot log (output of dmesg).

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Qualcomm Snapdragon is product of Qualcomm Technologies, Inc.