Yocto Chromium

Chromium recipes for yocto

Introduction

Let's build Chromium on yocto. You can build both X11 and Ozone GBM. This recipes is for chromium developers who want to build chromium on yocto. You may checkout chromium source in your computer already. You will build Chromium using your local source. Yocto build system is smart enough to not copy or change your local source.

Acknowledge: @tmpsantos teach me everything.

I have experience to build chromium on chrome os and tizen. Yocto is way better. Yocto doesn't use chroot, so you can keep the source in another partition of storage.

Contents

• Design - the architecture behind
• Howto - set up the system environment, build and run

Design

• similar to Crosswalk

Howto

Important caveat: this project only covers x86 or x64. I didn't test ARM but there is no reason to not be possible to build for ARM. For Chromium Ozone-GBM, I test it on Intel Haswell and newer generation GPU. That said, we don't have plans to extend it to any other category of devices. For testing, development and deployment we recommend the MinnowBoard MAX or Intel Haswell without any external GPU.

This guide will help you to build a bootable image with the Chromium. Most of the toolchain needed to build comes from Yocto Poky and it's expected to use just a few of your system's dependencies. We use Ubuntu 14.04 LTS (Trusty Tahr) in particular, but there's no reason to not use any other different system. Besides, make sure you have at least 45 GB of disk space to store all the sources and a few types of images to be built.

Firstly, you will need anyway a couple of your distribution tools and development packages:

$ sudo apt-get install gawk wget git-core diffstat unzip texinfo \
gcc-multilib build-essential chrpath libsdl1.2-dev xterm gyp

then download the needed stuff:

$ mkdir yocto
$ cd yocto/

$ git clone http://git.yoctoproject.org/git/poky
$ git clone https://github.com/otcshare/yocto-chromium.git

• If you want stable branch of poky, checkout git checkout dizzy. I usually work on master.

• jump to its build environment:

  $ cd poky/
  $ source oe-init-build-env
  
  

You had no conf/local.conf file so a configuration file has therefore been created for you with some default values, but we need still to add the meta-browser layers in conf/bblayers.conf - mind to change the lines below with the full path of the directory you are cloning the repos (in our case it was /media/yocto/) :

BBLAYERS ?= " \
/media/yocto/poky/meta \
/media/yocto/poky/meta-yocto \
/media/yocto/poky/meta-yocto-bsp \
/media/yocto/yocto-chromium/meta-chromium \
"

then, set in conf/local.conf the genericx86-64 machine (you could try a different architecture but we haven't yet):

MACHINE ?= "genericx86-64"

then, set chromium configuration:

# to use libav
LICENSE_FLAGS_WHITELIST = "commercial"
# your local chromium tree
CHROMIUM_LOCAL_PATH = "/home/dshwang/chromium/src"
# you might use "out" directory for linux chromium already.
CHROMIUM_OUT_DIR = "out_yocto"
# if you want to build shared library
PACKAGECONFIG_append_pn-chromium = " component-build"
IMAGE_INSTALL_append = " chromium"

Now close the file and let's build whole yocto image including chromium also. core-image-sato is the referece image including window manager using X11.

$ bitbake core-image-sato

You can cook only the package:

$ bitbake chromium

If you want to compile only, you can do it.

$ bitbake -c compile chromium

It will take several hours to download much of the dependencies, build and etc. Relax now. If everything goes fine, you will have the following directory with the images built in inside:

$ ls tmp/deploy/images/genericx86-64/*.hddimg
$ tmp/deploy/images/genericx86-64/core-image-sato-genericx86-64-20150307113028.hddimg
$ tmp/deploy/images/genericx86-64/core-image-sato-genericx86-64.hddimg

Make sure you have now inserted a USB flash drive, checking the correct file descriptor that Linux will be using with the sudo fdisk -l command. For example in our system it is /dev/sdc, so the following is what we used to flash it:

$ cd tmp/deploy/images/genericx86-64/
$ sudo dd if=core-image-sato-genericx86-64.hddimg of=/dev/sdc
$ sync 
$ sudo eject /dev/sdc

You are able now to boot the flash drive in your hardware and play around with Chromium browser.

Ozone GBM

• change local.conf as follows to build Chromium Ozone GBM
• Add "ozone-gbm" to "PACKAGECONFIG"
• GBM requires the latest version of kernel

PACKAGECONFIG_append_pn-chromium = " component-build ozone-gbm"
PREFERRED_VERSION_linux-yocto = "3.19%"

When you build whole yocto image, use core-image-minimal which doesn't include X11 and window manager.

$ bitbake core-image-minimal

Tips

ICECC

add following lines in local.conf

PARALLEL_MAKE = "-j 80"
ICECC_PATH = "/home/dshwang/thirdparty/icecream/install/bin/icecc"
INHERIT += "icecc"

Before bitbake you must exclude icecc toolchain wrapper path(e.g. /usr/lib/icecc/bin) from $PATH

• Reference
• icecc.bbclass
• Using IceCC in OpenEmbedded

Icecc trouble shooting

• icecc you builds by yourself gets along with yocto. don't worry.

• exception 23

• this means that your machine makes wrong toolchain.

ICECC[24079] 13:52:14: compiler did not start - compiled on 10.237.72.78
ICECC[24079] 13:52:14: got exception 23 (10.237.72.78) 

• A1: purge annoying hardening-wrapper (which wastes my 2 days) sudo apt-get purge hardening-wrapper hardening-includes
• A2: purge clang and all gcc and then reinstall only minimal gcc

Add more tools in minimal images

• you might need "bash", "ssh", "sshfs" for more convinient embedded development.
• checkout meta-openembedded and then add following lines to bblayers.conf

BBLAYERS ?= " \
   ...
  /d/workspace/yocto/meta-openembedded/meta-oe \
  /d/workspace/yocto/meta-openembedded/meta-filesystems \
  "

• add packages you want ot local.conf

-EXTRA_IMAGE_FEATURES = "debug-tweaks"
+EXTRA_IMAGE_FEATURES = "debug-tweaks ssh-server-dropbear"

-IMAGE_INSTALL_append = " chromium"
+IMAGE_INSTALL_append = " chromium sshfs-fuse bash"

How to use sshfs

• install sshfs on your machine, then add yourself to the fuse group:
• Refer Ubuntu SSHFS

> sudo apt-get install sshfs
> sudo gpasswd -a $USER fuse

• ssh to device

> ssh root@$<YOCTOURL>
$

• (optional) you can use bash. Do you remember we added bash package on the image :)

$ bash

• ssh from device to your machine because it loads some kernel module, which means sshfs has a bug not-loading it.

$ ssh <ID>@<HOST>
> [crtl + d]

• sshfs mounts host chromium directory on device

$ mkdir remote
$ sshfs -o idmap=user <ID>@<HOST>:<chromium path> /home/root/remote/

• Enjoy hack

• unmount if needed

fusermount -u /home/root/remote

my conf

• Refer to my local.conf and bblayers.conf

Reference

• META Crosswalk project
• Yocto Quick start
• Yocto dev manual
• meta-crosswalk-embedded project