Install the required packages

Some packages are needed to compile the Linux Kernel for UDOO boards. E.g. in Ubuntu 14.04 it is necessary to install the following packages:

sudo apt-get update
sudo apt-get install gawk wget git diffstat unzip texinfo gcc-multilib \
     build-essential chrpath socat libsdl1.2-dev xterm picocom ncurses-dev lzop \
     gcc-arm-linux-gnueabihf

Get the kernel sources from GitHub

Create a develop folder

mkdir udoo-dev
cd udoo-dev

then download the sources:

git clone https://github.com/UDOOboard/linux_kernel
cd linux_kernel

The default branch 3.14-1.0.x-udoo is the one where we are working on for the UDOO QUAD/DUAL. It is based on 3.14.56 Freescale community kernel.

Load the default kernel configuration

UDOO Neo has a dedicated default kernel configuration that you can import with:

ARCH=arm make udoo_neo_defconfig

(optional) Personalize the kernel configuration

Add or remove kernel modules to fit your project:

ARCH=arm make menuconfig

Compile sources

To build the kernel image, type:

ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- make zImage -j5

You can safely tweak the -jX parameter. For instance, on quad core CPUs with two threads per core, you can use -j8.

The build can take several minutes, approximately from 2 to 15, depending on your PC host or VM configuration.

[...]
  Kernel: arch/arm/boot/Image is ready
  LZO     arch/arm/boot/compressed/piggy.lzo
  CC      arch/arm/boot/compressed/decompress.o
  CC      arch/arm/boot/compressed/string.o
  SHIPPED arch/arm/boot/compressed/hyp-stub.S
  SHIPPED arch/arm/boot/compressed/lib1funcs.S
  SHIPPED arch/arm/boot/compressed/ashldi3.S
  SHIPPED arch/arm/boot/compressed/bswapsdi2.S
  AS      arch/arm/boot/compressed/hyp-stub.o
  AS      arch/arm/boot/compressed/lib1funcs.o
  AS      arch/arm/boot/compressed/ashldi3.o
  AS      arch/arm/boot/compressed/bswapsdi2.o
  AS      arch/arm/boot/compressed/piggy.lzo.o
  LD      arch/arm/boot/compressed/vmlinux
  OBJCOPY arch/arm/boot/zImage
  Kernel: arch/arm/boot/zImage is ready

Compile Device Trees

ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- make dtbs -j5

Compile the modules

ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- make modules -j5

Copy the kernel to the SD card

You can overwrite the kernel on a UDOObuntu SD card with the following commands:

BOOT_PARTITION=/path/to/boot-partition
ROOT_PARTITION=/path/to/root-partition

cp arch/arm/boot/zImage $BOOT_PARTITION
cp arch/arm/boot/dts/*.dtb $BOOT_PARTITION/dts
ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- make firmware_install modules_install INSTALL_MOD_PATH=$ROOT_PARTITION

Heads up! Be aware that if you have used the DTEditor previously, u-boot will load DTBs from /boot/dts-overlay. Disable this via /boot/uEnv.txt or copy your modified DTBs to that directory.

This page was last updated on Thursday, September 14, 2017 at 10:48 AM.