Open webOS

Introduction

This directory and the repository in which it resides hold upper level code used to aggregate the various OpenEmbedded layers, into webOS. It does this using Git submodules which are handled transparently only for the initial build.

Set-up

Because this repository uses Git submodules, you must register your SSH key with GitHub in order to build it. For help on doing this, visit [Generating SSH Keys] (https://help.github.com/articles/generating-ssh-keys).

Build the webos-image by cloning the git repository:

 git clone https://github.com/openwebos/build-webos.git

Note: If you populate it by downloading an archive (zip or tar.gz file), then you will get the following error when you run 'mcf':

 fatal: Not a git repository (or any parent up to mount parent). Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYTEM not set).

Prerequisites

Before you can build, you will need some tools. If you try to build without them, bitbake will fail a sanity check and tell you what's missing, but not really how to get the missing pieces. You can force all of the missing pieces to be installed using:

$ sudo scripts/prerequisites.sh

This has been tested on Ubuntu 11.04 and 12.04 32-bit.

Note: Builds on 64-bit machines are not currently supported.

Building

To configure the build for the qemux86 emulator and to fetch the Git submodule sources:

$ ./mcf -p 0 -b 0 qemux86

The -p and -b options set the make and bitbake parallelism values to the number of CPU cores found on your computer.

To build the bitbake component, type:

$ make <componentName>

To kick off a full build of Open webOS, type the following, (which may take two hours on a reasonably fast workstation, or many more hours on a slower laptop or VM):

$ make webos-image

Using your own recipe files

The "mcf" script automatically clones the meta-webos repository from GitHub into the build-webos folder.
If adding a new component or testing a change to a recipe file, you will need to switch over to using your own clone of meta-webos:

• Delete the standard meta-webos folder from within the build-webos folder on your computer
• Copy the modified meta-webos folder and its contents under the build-webos folder
• Make the new or modified component to test your recipe

Caution: Rerunning the "mcf" script will overwrite the meta-webos folder in build-webos. Keep a separate clone of meta-webos for your development work.
To be safe, delete the copy of meta-webos under the build-webos folder before running the "mcf" script.

Running

To run the resulting build in the qemux86 emulator, type:

$ cd BUILD-qemux86
$ source bitbake.rc 
$ runqemu webos-image qemux86

Cleaning

To blow away everything and do a clean build, you can remove the build folder and run ./mcf again to create a new one:

$ rm -rf BUILD-qemux86
$ ./mcf -p 0 -b 0 qemux86

Note that the steps above are more efficient than blowing away the entire webOS tree, as that would also purge your downloads and sstate-cache folders.

Using the ARM emulator

To build for the ARM emulator, specify qemuarm to mcf instead of qemux86. To run the resulting build, type:

$ cd BUILD-qemuarm
$ source bitbake.rc 
$ runqemu webos-image qemuarm

Images

The following images have been tested and should build:

core-image-minimal: This is inherited verbatim from openembedded-core.

webos-image: This is an aggregator for webOS-specific components.

Adding a new package to webOS

The procedure to add new packages to the webOS image depends on the build procedure for each individual package.

1. For a CMake-based build, you will need to inherit from the webos_cmake class. An example recipe can be found in librolegen.bb.

2. For autoconfig/automake based build procedure, you will need to inherit from the autotools class. An example recipe can be found in c-ares_1.7.4.bb.

3. If the package source is fetched from Github, you will need to add the following to your local.conf file. You must not set SRCREV in the package recipe directly.

    $ vi BUILD-<machine>/conf/local.conf
    SRCREV_pn-<pkg name> ?= "commit-id" or "${AUTOREV}"
   

4. To include the new package in the image, add the following to your local.conf. Once the package is functional, let us know and we'll add it permanently to the image.

    $ vi BUILD-<machine>/conf/local.conf
    IMAGE_INSTALL_append = " <pkg name>"  # Note the space before the name
   

5. Package checksum is calculated using the Message-Digest algorithm. Use md5sum to generate the MD5 hash used for LIC_FILES_CHKSUM.

Build times

Typical build times on modern servers are running anywhere from 8 - 20 hours for single threaded builds. These times, and their variations, are primarily due to the cost of downloading source over the internet. Local mirrors are expected to cut these times by at least an order of magnitude as well as to enable sharing of prebuilt binaries. With preseeded downloads and very high parallelism, (48-core machines of which only about 16 - 24 are utilized), the build can be brought down to under an hour.

Copyright and License Information

Unless otherwise specified, all content, including all source code files and documentation files in this repository are:

Copyright (c) 2008 - 2012 Hewlett-Packard Development Company, L.P.

Unless otherwise specified or set forth in the NOTICE file, all content, including all source code files and documentation files in this repository are: Licensed under the Apache License, Version 2.0 (the "License"); you may not use this content except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.