Building the Image file for Beagle Bone Black

Step by step procedure from RTS for building the image file for Beagle bone black which includes

1. uboot-image

2. z-image

3. MLO(primary bootloader)

4. Board support package 

5. RFS(root file system)

Steps to make an U-boot image in linux for Beaglebone Black (u-boot.img)

Step 1 : Firstly, install the arm cross compiler. it is a 64-bit gcc compiler. download it from the link below.

wget -c https://releases.linaro.org/components/toolchain/binaries/6.4-2017.11/arm-linux-gnueabihf/gcc-linaro-6.4.1-2017.11-x86_64_arm-linux-gnueabihf.tar.xz

Step 2 : Next, extract the downloaded zip file. preferably, download and extract it in an user created directory.

tar xf gcc-linaro-6.4.1-2017.11-x86_64_arm-linux-gnueabihf.tar.xz

Step 3 : Now, add the path of the cross compiler in order to set it as your cross-compiler.

export CC=`pwd`/gcc-linaro-6.4.1-2017.11-x86_64_arm-linux-gnueabihf/bin/arm-linux-gnueabihf-

Step 4 : Check the version of the c ross-compiler. make sure it is exported.

${CC}gcc --version

Step 5 : Next step is to build the bootloader. the next step will clone the standard u-boot from github into a directory named u-boot

git clone https://github.com/u-boot/u-boot

Step 6 : Change the present working directory as u-boot and check the version

cd u-boot/

git checkout v2018.01 -b tmp

Step 7 : Now you need to apply some patches based on the processor and board you will be using.

wget -c https://rcn-ee.com/repos/git/u-boot-patches/v2018.01/0001-am335x_evm-uEnv.txt-bootz-n-fixes.patch

wget -c https://rcn-ee.com/repos/git/u-boot-patches/v2018.01/0002-U-Boot-BeagleBone-Cape-Manager.patch

patch -p1 < 0001-am335x_evm-uEnv.txt-bootz-n-fixes.patch

patch -p1 < 0002-U-Boot-BeagleBone-Cape-Manager.patch

Step 8 : Build the bootloader with the cross compiler you chose

make ARCH=arm CROSS_COMPILE=${CC} distclean

make ARCH=arm CROSS_COMPILE=${CC} am335x_evm_defconfig

make ARCH=arm CROSS_COMPILE=${CC}

Kernel Image

This will build the kernel along with the device trees and modules(zImage)

Step 1:

Download the kernel files from github

git clone https://github.com/RobertCNelson/bb-kernel

Step 2:

Migrate into the kernel directory

cd bb-kernel/

Step 3:

Getting into the required directory depending on the version of the processor for am33x-rt-v4.14,

git checkout origin/am33x-rt-v4.14 -b tmp

Step 4:

Build the kernel

./build_kernel.sh

Step 5:

Download the board support package

git clone https://github.com/RobertCNelson/ti-linux-kernel-dev.git

Step 6:

GET INTO THE BSP DIRECTORY AVAILABLE IN THE /dev DIRECTORY

cd ti-linux-kernel-dev/

Step 7:

Getting into the required directory depending on the version of bsp

For TI v4.14.x,

git checkout origin/ti-linux-rt-4.14.y -b tmp

Step 8:

Build the kernel along with the bsp

./build_kernel.sh

RFS

According to the Operating System you are working on, download the file for root file system

->FOR UBUNTU 16.04

USERNAME: ubuntu

PASSWORD: temppwd

Step 1:

wget -c https://rcn-ee.com/rootfs/eewiki/minfs/ubuntu-16.04.3-minimal-armhf-2017-12-09.tar.xz

Step 2 :

The next command will help you verify the rfs.

sha256sum ubuntu-16.04.3-minimal-armhf-2017-12-09.tar.xz

running the above command will give you a result as below

cacc1a8c56649808e3bc27ca58f94dbe817b9e86e660780009a3535709823cc1 ubuntu-16.04.3-minimal-armhf-2017-12-09.tar.xz

Step 3:

Unzip the rfs

tar xf ubuntu-16.04.3-minimal-armhf-2017-12-09.tar.xz

->FOR DEBIAN 9

USERNAME: debian

PASSWORD: temppwd

USERNAME: root

PASSWORD: root

Step 1:

wget -c https://rcn-ee.com/rootfs/eewiki/minfs/debian-9.3-minimal-armhf-2017-12-09.tar.xz

Step 2:

The next command will help you verify the rfs.

sha256sum debian-9.3-minimal-armhf-2017-12-09.tar.xz

Running the above command will give you a result as below

5120fcfb8ff8af013737fae52dc0a7ecc2f52563a9aa8f5aa288aff0f3943d61 debian-9.3-minimal-armhf-2017-12-09.tar.xz

Step 3: Unzip the rfs

tar xf debian-9.3-minimal-armhf-2017-12-09.tar.xz