{{ImportantMessage|text=As the structure of the BELK/BXELK is based on several tools, it is strongly recommended the reading of [[Logical_structure_of_Bora_and_BoraX_Embedded_Linux_Kits_(BORA_SOM/BELK-L/General/BXELK)Logical_structure_of_BELK|this document]] first to get an overview.

{{ImportantMessage|text=As the XUELK BELK/BXELK kit is based on Yocto, the implementation of the MVM follows the approach described [[Managed_Virtual_Machine_(MVM)#Yocto-based_Linux_distribution|here]]. As such, the reading of [[Managed_Virtual_Machine_(MVM)#Yocto-based_Linux_distribution|this section]] is highly recommended.

 <section begin=BELK/>  =Introduction=Building the Yocto BSP== ===Quick reference==={| class="wikitable" border="1"|+Repository Information|-! Repository| BSP Manifest| Yocto BSP Layer|-! URL| git@git.dave.eu:bora/bora-bsp.git| git@git.dave.eu:bora/meta-bora.git|-! stable branch| bora-morty| bora-morty|-! stable tag| belk-4.1.4| belk-4.1.4|} {| class="wikitable" border="1"|+Build targets! Name! Description|-| dave-image-devel| This image include tools for development/debugging|-| dave-image-networking| In addition <code>dave-image-devel</code>, this image provides several networking tools|} 

Besides the pre-built root file systems, 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 <code>smart</code> tool. Please refer to [[Advanced_use_of_Yocto_build_system_(BORA_SOM/BELK-L/Development/BXELK)Advanced_use_of_Yocto_build_system#Using_pre-built_package_archive|this section]] for more details.

For more general information regarding the Yocto build system, please refer the [[:Category:Yocto|dedicated category page]].

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

{{ImportantMessage|text=The procedure described here makes use of a huge number of pre-built software modules which are included in the MVM. Technically speaking, the developer can run a Yocto-based '''full''' build process to (re)generate from scratch all these modules. However, this This process requires a lot of hardware resources in terms of disk storage, RAM, and processing power. For this reason, '''it also is discouraged recommended to consider the use the MVM to perform such a build'''. Using of a physical machine is '''recommended''' instead. For more details on this topic, please refer to [[Advanced_use_of_Yocto_build_system_(BORA_SOM/BELK-L/Development/BXELK)Advanced_use_of_Yocto_build_system|this document]] which talks about the advanced use of the Yocto build system.}}

===Prerequisites===BELK/BXELK MVM is already configured to build this Yocto version/configuration, therefore no additional packages have to be installed by the user in order to run the Yocto BSP build process. === Initialize the build environment ====

dvdk@dvdk-vm:~/lynxbelk$ curl http://commondatastorage.googleapis.com/git-repo-downloads/repo -1 > repodvdk@dvdk-vm:~/lynxbelk$ chmod a+x repodvdk@dvdk-vm:~/lynxbelk$ ./repo init -u git@git.dave.eu:lynxbora/lynxbora-bsp.git -b lynxbora-fidomortydvdk@dvdk-vm:~/lynxbelk$ ./repo syncdvdk@dvdk-vm:~/belk$ source bora-bsp-init-env.sh

=== Run the build ==unauthenticated git protocol error ====={{ImportantMessage|text=Since March 15th, 2022, GitHub stopped accepting DSA keys. RSA keys uploaded after Nov 2, 2021 will work only with SHA-2 signatures.The deprecated MACs, ciphers, and unencrypted Git protocol are permanently disabled.<br>For more details on this topic, please refer to [[MISC-TN-015:_Yocto_and_git_protocol_error|this Technical Note]].}}

==== Running the build ====Please note that even the basic root file system requires a few hours to build on a mid/hi range desktop (4-6 cores, 8-12 GiB RAM) also depending on your Internet connection speed (all sources are fetched from the network). Nearly 20GiB of disk space is required for the build. Moreover, building inside the DVDK adds some overhead, The process may be slowed down significantly since the performances of a virtual machine are reduced if compared to the physical hardware. Thus, it's recommended to check the hardware capabilities of the host system and, when building with Yocto is required, developers should to consider the following options: * migrating Migrating the build system to a physical machine* assuming Assuming that the host system has the required resources, extending the hardware capabilities of the default DVDK MVM (eg: e.g. adding more cores and disk space).

dvdk@dvdk-vm:~/lynx$ DISTRO=fsl-imx-fb MACHINE=sbc-lynx source lynx-setup-release.sh -b build-fb -e fbdvdk@dvdk-vm:~/lynxbelk/build$ bitbake lynx<target-image-networkingname>

The Once the build process is completed, the resulting files (the U-Boot binaries, the Linux kernelimage, devicetree and u-boot binariesthe device tree blob, plus the .tar.gz compressed root file systemimage, etc.) will then be available inside ''in <code>build/tmp/deploy/images/sbc-lynx''bora</code>.

In addition to ====Generating the typical imagesSDKs====After creating an image as described in the previous version, the XUELK provides corresponding SDK can be generated by issuing the following toocommand:*<codepre class="workstation-terminal">lynxbitbake <target-image-networkingname> -sbcc populate-lynx-xenosdk</codepre>**With respect to the Again, replace <code>lynx<target-image-networkingname></code> image, this includes additional libraries required to run with one of the Linux kernel featuring the Xenomai real-time extension. For more details about it, please refer to https://xenomai.org/images listed in [[#Quick reference|here]].

=== Build Building additional packages ===

To build additional packages the user must first enter the directory where the <code>lynxbora-setupbsp-releaseinit-env.sh</code> is placed and source it

dvdk@dvdk-vm:~/lynxbelk$ DISTRO=fsl-imx-fb MACHINE=sbcsource bora-lynx source lynxbsp-setupinit-releaseenv.sh -b build-fb -e fbdvdk@dvdk-vm:~/lynxbelk/build$

dvdk@dvdk-vm:~/lynxbelk/build$ bitbake memtester

dvdk@dvdk-vm:~/lynxbelk/build$ ls -l tmp/deploy/rpm/cortexa7hf_vfp_neoncortexa9hf_neon/memtester*-rw-r--r-- 1 dvdk dvdk 9967 10692 Sep 7 12 16:05:43 tmp/deploy/rpm/cortexa7hf_vfp_neoncortexa9hf_neon/memtester-4.13.30-r0.cortexa7hf_vfp_neoncortexa9hf_neon.rpm-rw-r--r-- 1 dvdk dvdk 25544 27693 Sep 7 12 16:05:43 tmp/deploy/rpm/cortexa7hf_vfp_neoncortexa9hf_neon/memtester-dbg-4.13.30-r0.cortexa7hf_vfp_neoncortexa9hf_neon.rpm-rw-r--r-- 1 dvdk dvdk 2884 2872 Sep 7 12 16:05:42 tmp/deploy/rpm/cortexa7hf_vfp_neoncortexa9hf_neon/memtester-dev-4.13.30-r0.cortexa7hf_vfp_neoncortexa9hf_neon.rpm-rw-r--r-- 1 dvdk dvdk 5611 5903 Sep 7 12 16:05:44 tmp/deploy/rpm/cortexa7hf_vfp_neoncortexa9hf_neon/memtester-doc-4.13.30-r0.cortexa7hf_vfp_neoncortexa9hf_neon.rpm

                              The generic procedure to generate the Yocto BSP image is the following:<pre classsection end="board-terminal">dvdk@dvdk-vm:~/belk$ curl http://commondatastorage.googleapis.com/git-repo-downloads/repo > repodvdk@dvdk-vm:~/belk$ chmod a+x repodvdk@dvdk-vm:~/belk$ ./repo init -u git@git.dave.eu:bora/bora-bsp.git -b bora-mortydvdk@dvdk-vm:~/belk$ ./repo syncdvdk@dvdk-vm:~/belk$ source bora-bsp-init-env.shdvdk@dvdk-vm:~/belk/build$ bitbake <target-image-name></pre>bora-imagebora-image-develbora-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 <code>git clone <git_remote_repository></code> command *synchronize a source tree entering the repository directory and launching the <code>git fetch origin</code> command.Please note that git fetch doesn't merge the commits on the current branch. To do that, the developer should run the <code>git merge</code> command or replace the ''fetch-merge'' process with a single <code>git pull</code> 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). {{ImportantMessage|text=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 [[Advanced_use_of_Yocto_build_system_(BELK/BXELK)|this page]].}}   The following table lists the pre-built root file systems included in the MVM.{| class="wikitable" border="1"!Kit version<br>BELK<br>BXELK!Image name!Build commands!Path|-|rowspan="3"|<br>4.0.0<br>2.0.0|<code>bora-image</code>|<pre>dvdk@dvdk-vm:~/belk$ curl http://commondatastorage.googleapis.com/git-repo-downloads/repo > repodvdk@dvdk-vm:~/belk$ chmod a+x repodvdk@dvdk-vm:~/belk$ ./repo init -u git@git.dave.eu:bora/bora-bsp.git -b bora-mortydvdk@dvdk-vm:~/belk$ ./repo syncdvdk@dvdk-vm:~/belk$ source bora-bsp-init-env.shdvdk@dvdk-vm:~/belk/build$ bitbake bora-image</pre>|<code>/home/dvdk/bora/rfs/belk-4.0.0</code>|-|<code>bora-image-devel</code>|<pre>dvdk@dvdk-vm:~/belk$ curl http://commondatastorage.googleapis.com/git-repo-downloads/repo > repodvdk@dvdk-vm:~/belk$ chmod a+x repodvdk@dvdk-vm:~/belk$ ./repo init -u git@git.dave.eu:bora/bora-bsp.git -b bora-mortydvdk@dvdk-vm:~/belk$ ./repo syncdvdk@dvdk-vm:~/belk$ source bora-bsp-init-env.shdvdk@dvdk-vm:~/belk/build$ bitbake bora-image-devel</pre>|<code>/home/dvdk/bora/rfs/belk-4.0.0</code>|-|<code>bora-image-networking</code>|<pre>dvdk@dvdk-vm:~/belk$ curl http://commondatastorage.googleapis.com/git-repo-downloads/repo > repodvdk@dvdk-vm:~/belk$ chmod a+x repodvdk@dvdk-vm:~/belk$ ./repo init -u git@git.dave.eu:bora/bora-bsp.git -b bora-mortydvdk@dvdk-vm:~/belk$ ./repo syncdvdk@dvdk-vm:~/belk$ source bora-bsp-init-env.shdvdk@dvdk-vm:~/belk/build$ bitbake bora-image-networking</pre>|<code>/home/dvdk/bora/rfs/belk-4.0.0</code>|-|}  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.{| class="wikitable" border="1"!Kit version<br>BELK<br>BXELK!SDK name!Build commands!Path|-|rowspan="3"|<br>4.0.0<br>2.0.0|<code>bora-image</code>|<pre>bitbake bora-image -c populate-sdk</pre>|<code>/home/dvdk/bora/sdk/belk-4.0.0/sysroots/cortexa9hf-neon-xilinx-linux-gnueabi</code>|-|<code>bora-image-devel</code>|<pre>bitbake bora-image-devel -c populate-sdk</pre>|<code>/home/dvdk/bora/sdk/belk-4.0.0/sysroots/cortexa9hf-neon-xilinx-linux-gnueabi</code>|-|<code>bora-image-networking</code>|<pre>bitbake bora-image-networking -c populate-sdk</pre>|<code>/home/dvdk/bora/sdk/belk-4.0.0/sysroots/cortexa9hf-neon-xilinx-linux-gnueabi</code>|-|}  About C/C++ application development and debugging, please refer to [[Debugging_with_Eclipse_(MVM)|this page]].