CODEWITHSUNDEEP
linux-kernelbeagleboneblack
Alex Marshall
Alex Marshall

Reputation: 10322

Reliable build of the Linux Kernel for the BeagleBone Black

Is there a reliable build of the Linux kernel for the BeagleBone Black platform anywhere ? I've followed the instructions here, as well as numerous other places, and none of them work. Either the modules don't build (the .ko files just don't get built and can't be found in the case of the link above), or there's missing build targets for the kernel. I'm using the Linaro ARM compiler (arm-linux-gnueabihf-gcc) cross compiling on 32-bit x86 Ubuntu 14.04.

Specifically, I've checked out the source at the BeagleBone Git repository, branches 3.8, 3.11, 3.12, 3.13 and 3.14. I've also checked out a 3rd party git clone here. The problems I've encountered are as follows:

In the cases where I could compile a kernel, I copied it to a fresh, vanilla board in memory using a TFTP boot server from U-Boot, and booted the kernel in memory. However, none of the successfully compiled kernels could work properly because they were missing their modules / firmware / dtbs. What could be causing the incorrect patching ? Surely, the developers who've written the code and patches must have tested it, so there may be something wrong with my workspace, though I can't imagine what at this point. The commands I used were the same as those at link 1.

Upvotes: 10

Views: 9428

Answers (3)

pysup
pysup

Reputation: 61

I was finally able to boot the BBB with a new kernel 3.14

I am on a beagleboneblack rev C with debian pre-installed.

I basically followed steps here http://dev.ardupilot.com/wiki/building-for-beaglebone-black-on-linux/

Kernel download: (I didn't use git, limited bandwidth...) https://github.com/beagleboard/linux/archive/3.14.tar.gz

Build (done on a Ubuntu 14.04) : (I am not sure if some steps are not relevant or redundant)

Install mkimage

sudo apt-get install libssl-dev
wget ftp://ftp.denx.de/pub/u-boot/u-boot-latest.tar.bz2
tar -xjf u-boot-latest.tar.bz2
cd u-boot-2014.10/
make sandbox_defconfig tools-only
sudo install tools/mkimage /usr/local/bin

Download am335x-pm-firmware.bin from http://arago-project.org/git/projects/?p=am33x-cm3.git;a=tree;f=bin;h=75a5de7aa94ff6ccbfb1b3b9dc80bc2fe5b423bf;hb=refs/heads/master and copy to kernel directory

Build the kernel

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- bb.org_defconfig
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- menuconfig
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- uImage dtbs LOADADDR=0x80008000 -j4
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- modules -j4
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- am335x-boneblack.dtb -j4

Install Modules

mkdir -p ../export/rootfs
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- INSTALL_MOD_PATH=../export/rootfs/ modules_install

Now copy modules to /lib/modules/ directory in your beaglebone black (create a new directory for the modules)

cd ../export/rootfs/lib/modules/
rsync -avz 3.14.25/ [email protected]:/lib/modules/3.14.25/

Next is to copy the zImage and am335x-boneblack.dtb to the BBB

copy zImage from arch/arm/boot to /boot/uboot/ of BBB

copy am335x-boneblack.dtb from arch/arm/boot/dts to /boot/uboot/dtbs

If you replace the existing zImage and am335x-boneblack.dtb with new ones directly and they don't work, you will be in trouble. I stored the new images in a folder in /boot/uboot and manipulated environment variables in uboot to pick the one i wanted.

I know, I could have used tftpserver..

I hope it helps someone. I spent a lot of time on this which should have been very straightforward :(

Upvotes: 5

ragu foss
ragu foss

Reputation: 101

I also followed the link you have mentioned and I am able to boot the BBB. I am using the mainline kernel from https://www.kernel.org/. The following are the steps I followed

  1. Download the latest kernel. My version is 3.18-rc4
  2. Use "omap2plus_defconfig" which is the default config for beaglebone black

  3. Make commands are

    make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- omap2plus_defconfig -j4

    make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- uImage dtbs LOADADDR=0x80008000 -j4.

    The image produced is present in the following path.

    arch/arm/boot/uImage uImage

    arch/arm/boot/dts/am335x-boneblack.dtb

  4. After this compile the modules.

    make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- modules -j4

  5. I was using busybox and NFS server as root

Compiler used is arm-linux-gnueabi-gcc. With this I am able to boot successfully and run modules. It has the advantage that we are using the latest kernel available.

Upvotes: 10

dturvene
dturvene

Reputation: 2406

Yeah, the documentation is really out of date (circa 2011 or early 2012) and very confusing. First, the github/beagleboard/kernel area says it is deprecated and to use beagleboard/linux for the kernel. BUT, it is still be actively used 1) to add patches that have not been accepted to the kernel tree yet and 2) to add kernel configs specifically for the beaglebone devel builds. The bb.org_defconfig in the kernel tree does not turn on some debug stuff.

So.. both github/beagleboard/linux AND github/beagleboard/kernel work for me (3.14) on a BBB. If you want a standard image, use "linux"; if you want a bells-and-whistles image use "kernel".

Also, a more recent cross-compiler is in APT at gcc-arm-linux-gnueabihf. Make sure you have the "hf" (hard floating point unit) version. No need to depend on linaro.

I'll update the docs after I get the project rolling....

Upvotes: 1

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