TS-4900 Kernel Compile Guide

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To add drivers or reduce the size of our kernel, or to write custom kernel drivers you may need to build the kernel. These steps allow you to rebuild the kernel which is compatible with most of our Linux distributions.

This board has several kernels released and available in our git depending on the branch name.

  • The "master" branch is 3.10.17 and is largely outdated and replaced with later kernels. This is used with the old Yocto Dora builds.
  • The "imx_3.10.53_1.1.0_ga" kernel is a stable branch. Use this with Yocto Dizzy, Fido, or compatible with Debian Jessie.
  • The "imx_3.14.52_1.1.0_ga" branch is compatible with Yocto Jethro, and Debian.
  • The "imx_4.1.15_1.0.0_ga" branch is compatible with Yocto Jethro, Yocto Morty and Debian. Includes recent fixes not in older branches. This is recommended for most users.

You can pick the branch below. The kernel can be rebuilt by cross compiling from an X86/X86_64 Linux. Our default kernels are rebuilt using the toolchains built by Yocto. You can download the appropriate cross toolchain for your Linux system here:

Note: Older kernels will require older toolchains. These that are listed are recommended for the 4.1.15 which is our current recommended version. Use the Yocto Fido toolchain for older kernels.
chmod a+x poky*.sh
sudo ./poky*.sh

This will ask for the install directory for the toolchain. You can choose another directory than the default, but the following instructions will assume the defaults.

This also requires several tools from your distribution. For Ubuntu/Debian:

sudo apt-get install git build-essential lzop u-boot-tools libncursesw5-dev

Once those are installed:

git clone https://github.com/embeddedarm/linux-3.10.17-imx6.git -b imx_4.1.15_1.0.0_ga linux-tsimx6 --depth 1
# If you already have it cloned out you can "git pull" to get the latest changes
cd linux-tsimx6
# These export commands must be run every time before any make commands
export ARCH=arm
# For 64-bit
export CROSS_COMPILE=/opt/poky/2.0.2/sysroots/x86_64-pokysdk-linux/usr/bin/arm-poky-linux-gnueabi/arm-poky-linux-gnueabi-
# For 32-bit
#export CROSS_COMPILE=/opt/poky/2.0.2/sysroots/i686-pokysdk-linux/usr/bin/arm-poky-linux-gnueabi/arm-poky-linux-gnueabi-
export LOADADDR=0x10008000
make ts4900_defconfig
## Make any changes in "make menuconfig" or driver modifications, then compile
make -j8 && make -j8 uImage

To install this to a board you would use a USB SD reader and plug in the card. You must have an image already written to the card. This will not install the root filesystem with a bootable OS, only the kernel and drivers. Assuming your Linux rootfs is all on "sdc1":

export DEV=/dev/sdc1
sudo mount "$DEV" /mnt/sd
sudo rm /mnt/sd/boot/uImage
sudo cp arch/arm/boot/uImage  /mnt/sd/boot/uImage
sudo cp arch/arm/boot/dts/imx6*ts*.dtb /mnt/sd/boot/
INSTALL_MOD_PATH="/mnt/sd" sudo -E make modules_install 
INSTALL_HDR_PATH="/mnt/sd" sudo -E make headers_install
sudo umount /mnt/sd/

Change Kernel Splash Screen

The kernel splashscreen allows 224 colors. It also allows up to the full screen resolution, but for fastest boot speed it should be kept as small as possible. The image will be centered around a black background.

To convert your image, for example, "mylogo.png":

convert mylogo.png mylogo.ppm
ppmquant 224 mylogo.ppm > mylogo-224.ppm
pnmnoraw mylogo-224.ppm > logo_user_clut224.ppm
cp logo_user_clut224.ppm <kernel build sources>/drivers/video/logo/

Now recompile the kernel following the guide in the previous section.

Add the kernel cmdline "logo.nologo" in u-boot to completely disable the splash screen.