\subsection{Define a distribution}
\begin{frame}
\frametitle{why define a distribution?}
\begin{itemize}
\item naming of the toolchain (codenames, vendor)
		\pause
\item version numbers
		\pause
\item enable default features
\end{itemize}
\end{frame}

\begin{frame}
\frametitle{distro features: file-systems}
\begin{description}
\item[cramfs] CramFS support
\item[ext2] tools for supporting for devices with internal HDD/Microdrive
	for storing files (instead of Flash only devices)
\item[nfs] NFS client support (for mounting NFS exports on device)
\item[smbfs] SMB networks client support
	(for mounting Samba/Microsoft Windows shares on device)
\end{description}
\end{frame}

\begin{frame}
\frametitle{distro features: hardware support}
\begin{description}
\item[alsa] ALSA/sound support
	(OSS compatibility kernel modules installed if available)
\item[bluetooth] bluetooth support (integrated BT only)
\item[irda] IrDA support
		\pause
\item[wifi] WiFi support (integrated only).
\item[keyboard] keyboard support (e.g. keymaps will be loaded during boot)
\end{description}
\end{frame}

\begin{frame}
\frametitle{distro features: grahpics}
\begin{description}
\item[opengl] the Open Graphics Library, which is a cross-language,
	multi-platform application programming interface used for rendering two
	and three-dimensional graphics
\item[directfb] DirectFB support
\end{description}
\end{frame}

\begin{frame}
\frametitle{distro features: networking}
\begin{description}
\item[ipsec] IPSec support
\item[ipv6] IPv6 support
\item[ppp] PPP dialup support
\end{description}
\end{frame}

\begin{frame}
\frametitle{distro features: bus support}
\begin{description}
\item[pci] PCI bus support
\item[pcmcia] PCMCIA/CompactFlash support
\item[usbgadget] USB Gadget Device support (for USB networking/serial/storage)
\item[usbhost] USB Host support
	(allows to connect external keyboard, mouse, storage, network etc)
\end{description}
\end{frame}

\begin{frame}
\frametitle{distro features: software}
\begin{description}
\item[systemd] support for this init manager, which is a full replacement of
	for init with parallel starting of services, reduced shell overhead,
	and other features. This init manager is used by many distributions
\item[wayland] the Wayland display server protocol
	and the library that supports it
\item[x11] X server and libraries
\end{description}
\end{frame}

\begin{frame}[fragile]
\frametitle{use a DISTRO\_FEATURE}
Normally the distro features are used in package groups in a core layer.
e.g. 'meta/recipes-core/packagegroups/packagegroup-base.bb':
\begin{verbatim}
PACKAGES = ' \
	..
	${@base_contains("DISTRO_FEATURES", \
	                 "opengl", "packagegroup-opengl", "", d)} \
	..
	'
\end{verbatim}
\end{frame}