Building the Yocto BSP (BELK/BXELK)

Info Box Applies to Bora Applies to BORA Xpress

As the structure of the BELK/BXELK is based on several tools, it is strongly recommended the reading of this document first.

Introduction

As known, Linux needs a root file system to operate: a root file system must contain everything needed to support the Linux system (applications, settings, data, ..). The root file system is the file system that is contained on the same partition on which the root directory is located. The Linux kernel, at the end of its startup stage, mounts the root file system on the configured root device and finally launches the /sbin/init, the first user space process and "father" of all the other processes. For more information on the Linux filesystem, please refer to http://www.thegeekstuff.com/2010/09/linux-file-system-structure/.

BELK/BXELK provides one (or more) pre-built root file system, that can be used during the evaluation/development phase since it provides a relatively rich set of packages for working with the BORA platform. This root file system is located here: /home/dvdk/<target_name>/rfs/<kit_name>.

BELK/BXELK also provides a rich repository containing pre-built applications and libraries. These packages can be easily installed on the target by using the smart tool. Please refer to this section for more details.

How to build the Yocto BSP images including the U-Boot binary file, the Linux kernel image, and the target root file system image

The following procedure requires the access to the DAVE Embedded Systems' git repositories. The access to such repositories is granted to development kit's owners only. Please refer to this page for detailed instructions on how to get it.

The generic procedure to generate the Yocto BSP image is the following:

dvdk@dvdk-vm:~/belk$ curl http://commondatastorage.googleapis.com/git-repo-downloads/repo > repo
dvdk@dvdk-vm:~/belk$ chmod a+x repo
dvdk@dvdk-vm:~/belk$ ./repo init -u git@git.dave.eu:bora/bora-bsp.git -b bora-morty
dvdk@dvdk-vm:~/belk$ ./repo sync
dvdk@dvdk-vm:~/belk$ source bora-bsp-init-env.sh
dvdk@dvdk-vm:~/belk/build$ bitbake <target-image-name>

bora-image bora-image-devel bora-image-networking

The components listed in the table above can be kept in sync and up to date with DAVE Embedded Systems' repositories. Once the git account has been enabled, the developer can:

• clone the repository with the git clone <git_remote_repository> command
• synchronize a source tree entering the repository directory and launching the git fetch origin command.

Please note that git fetch doesn't merge the commits on the current branch. To do that, the developer should run the git merge command or replace the fetch-merge process with a single git pull command. Please note that the recommended method is the fetch-merge process. For further information on Git, please refer to the official Git Documentation (http://git-scm.com/documentation).

Technically speaking, the developer can run a Yocto-based full build process to (re)generate all the pre-built objects included in the MVM. However, this process requires a lot of hardware resources in terms of disk storage, RAM, and processing power. For this reason, it is discouraged to use the MVM to perform such build. Using a physical machine is recommended instead. For more details on this, please refer to this page.

The following table lists the pre-built root file systems included in the MVM.

Kit version BELK BXELK	Image name	Build commands	Path
4.0.0 2.0.0	bora-image	dvdk@dvdk-vm:~/belk$ curl http://commondatastorage.googleapis.com/git-repo-downloads/repo > repo dvdk@dvdk-vm:~/belk$ chmod a+x repo dvdk@dvdk-vm:~/belk$ ./repo init -u git@git.dave.eu:bora/bora-bsp.git -b bora-morty dvdk@dvdk-vm:~/belk$ ./repo sync dvdk@dvdk-vm:~/belk$ source bora-bsp-init-env.sh dvdk@dvdk-vm:~/belk/build$ bitbake bora-image	/home/dvdk/bora/rfs/belk-4.0.0
	bora-image-devel	dvdk@dvdk-vm:~/belk$ curl http://commondatastorage.googleapis.com/git-repo-downloads/repo > repo dvdk@dvdk-vm:~/belk$ chmod a+x repo dvdk@dvdk-vm:~/belk$ ./repo init -u git@git.dave.eu:bora/bora-bsp.git -b bora-morty dvdk@dvdk-vm:~/belk$ ./repo sync dvdk@dvdk-vm:~/belk$ source bora-bsp-init-env.sh dvdk@dvdk-vm:~/belk/build$ bitbake bora-image-devel	/home/dvdk/bora/rfs/belk-4.0.0
	bora-image-networking	dvdk@dvdk-vm:~/belk$ curl http://commondatastorage.googleapis.com/git-repo-downloads/repo > repo dvdk@dvdk-vm:~/belk$ chmod a+x repo dvdk@dvdk-vm:~/belk$ ./repo init -u git@git.dave.eu:bora/bora-bsp.git -b bora-morty dvdk@dvdk-vm:~/belk$ ./repo sync dvdk@dvdk-vm:~/belk$ source bora-bsp-init-env.sh dvdk@dvdk-vm:~/belk/build$ bitbake bora-image-networking	/home/dvdk/bora/rfs/belk-4.0.0

The following table lists the pre-built Yocto SDKs included in the MVM. These SDKs are associated with the root file system images mentioned above.

Kit version BELK BXELK	SDK name	Build commands	Path
4.0.0 2.0.0	bora-image	bitbake bora-image -c populate-sdk	/home/dvdk/bora/sdk/belk-4.0.0/sysroots/cortexa9hf-neon-xilinx-linux-gnueabi
	bora-image-devel	bitbake bora-image-devel -c populate-sdk	/home/dvdk/bora/sdk/belk-4.0.0/sysroots/cortexa9hf-neon-xilinx-linux-gnueabi
	bora-image-networking	bitbake bora-image-networking -c populate-sdk	/home/dvdk/bora/sdk/belk-4.0.0/sysroots/cortexa9hf-neon-xilinx-linux-gnueabi

About C/C++ application development and debugging, please refer to this page.