Sometimes you can find this log pattern:
audit(.:*): avc: denied
in kernel log (cat /proc/kmsg or dmesg)

It means that your selinux configuration isn’t well.

Yocto is not a distribution, it’s a flexible toolset and a development environment that you can use to build your own distribution. Yocto projects include many open-source libraries and you can choose what you need. Even write your own library. ref. by me

Official document.
Overview for v3.1.3
You might be interested in this article by Drew Moseley and in this short introductory video.

You should learn:

– for the host os:

Required Packages for the Build Host:
The list of packages you need on the host development system can be large when covering all build scenarios using the Yocto Project.


– for the target os:

These components and tools are open source projects and metadata that are separate from the reference distribution (Poky) and the OpenEmbedded build system. Most of the components and tools are downloaded separately.

OpenEmbedded Build System: The build system specific to the Yocto Project. The OpenEmbedded build system is based on another project known as “Poky”, which uses BitBake as the task executor. Throughout the Yocto Project documentation set, the OpenEmbedded build system is sometimes referred to simply as “the build system”. If other build systems, such as a host or target build system are referenced, the documentation clearly states the difference.

Poky: Poky is a reference embedded distribution and a reference test configuration. Poky provides the following:
– A base-level functional distro used to illustrate how to customize a distribution.
– A means by which to test the Yocto Project components (i.e. Poky is used to validate the Yocto Project).
– A vehicle through which you can download the Yocto Project.

Recipe: (zhuzii: like makefile) A set of instructions for building packages. A recipe describes where you get source code, which patches to apply, how to configure the source, how to compile it and so on. Recipes also describe dependencies for libraries or for other recipes. Recipes represent the logical unit of execution, the software to build, the images to build, and use the .bb file extension.

Opkg : (zhuzii: like dpkg in Ubuntu) A lightweight package management system based on the itsy package (ipkg) management system. Opkg is written in C and resembles Advanced Package Tool (APT) and Debian Package (dpkg) in operation.

others: ref-manual