\input{configpres}

\title{YOCTO - Basics}
\maketitle

\begin{frame}
\frametitle{Agenda}
\begin{itemize}
\item Workflow
\item Variable asssignments
\item Recipes
\item Append files
\item Classes
\item Tasks
\item Machines
\item Images
\item ADT
\end{itemize}
\end{frame}

\subsection{Workflow}
\begin{frame}[fragile]
\includegraphics[width=\textwidth]{images/yocto-workflow}
\end{frame}

\begin{frame}
\frametitle{classes}
\begin{itemize}
\item denoted by the .bbclass extension
\pause
\item base.bbclass is automatically included by all other classes and recipes.
\pause
\item common tasks and there execution order is defined in base.bbclass
\pause
\item tasks can be added, overridden, extended or used by other classes
\end{itemize}
\end{frame}

\begin{frame}
\frametitle{recipes}
\begin{itemize}
\item a .bb file inherits classes and populates them with data
\pause
\item bitbake is used to schedule the tasks defined in a recipe
\end{itemize}
\end{frame}

\begin{frame}
\frametitle{layers}
\begin{itemize}
\item a folder containing recipes, configs and classes
\pause
\item used to isolate different types of customizations from each other
\pause
\item e.g. own layer for machine specific stuff, one for own applications
\pause
\item extend, add, replace or modify recipes
\pause
\item add or replace class files
\pause
\item 'conf/layer.conf' is used to configure the layer
\pause
\item are added and ordered via BBLAYERS variable in build/conf/bblayers.conf
\pause
\item 'bitbake-layers show-layers' is used to show used layers
\end{itemize}
\end{frame}

\begin{frame}
\frametitle{layers \#2}
layers should be grouped by functionality
\begin{itemize}
\item custom toolchains (compilers, debuggers, profiling tools)
\pause
\item distribution specifications (i.e. meta-yocto)
\pause
\item BSP/machine settings (i.e. meta-yocto-bsp)
\pause
\item functional areas (selinux, networking, etc)
\pause
\item project specific changes
\pause
\item a layer is typically organized as a git repository
\end{itemize}
\end{frame}

\begin{frame}[fragile]
	\frametitle{directory layout}
	\begin{verbatim}
poky
├── bitbake
├── documentation
├── meta
├── meta-selftest
├── meta-skeleton
├── meta-yocto
├── meta-yocto-bsp
└── scripts
	\end{verbatim}
\end{frame}

\subsection{Variable assignments}
\begin{frame}
\frametitle{available operators}
\begin{itemize}
\item =
\item ?=
\item ??=
\item :=
\item += / =+
\item .= / =.
\end{itemize}
\end{frame}

\begin{frame}[fragile]
\frametitle{variable assignment with =}
\begin{verbatim}
VAR = "value"
\end{verbatim}
\pause
\begin{itemize}
	\item normal assignment
	\item values need to be surrounded by double quotes
\end{itemize}
\end{frame}

\begin{frame}[fragile]
\frametitle{early default assignment with ?=}
\begin{verbatim}
VAR ?= "1"
VAR ?= "2"
\end{verbatim}
\pause
\begin{itemize}
	\item VAR is set to "1" in this example
	\item if there are multiple assignments using ?= the first one is used
\end{itemize}
\end{frame}

\begin{frame}[fragile]
\frametitle{late default assignment with ??=}
\begin{verbatim}
VAR ??= "1"
VAR ??= "2"
\end{verbatim}
\pause
\begin{itemize}
	\item VAR is set to "2" in this example
	\item if there are multiple assignments using ??= the last one is used
\end{itemize}
\end{frame}

\begin{frame}[fragile]
\frametitle{assignment priorities \#1}
\begin{verbatim}
VAR_A ??= "12"
VAR_A ?= "34"

VAR_B ?= "12"
VAR_B ??= "34"
\end{verbatim}
\pause
\begin{itemize}
	\item VAR\_A contains "34"
	\item VAR\_B contains "12"
\end{itemize}
\end{frame}

\begin{frame}[fragile]
\frametitle{assignment priorities \#2}
\begin{verbatim}
VAR ?= "12"
VAR ??= "34"
VAR = "56"
VAR ?= "78"
VAR ??= "78"
\end{verbatim}
\pause
\begin{itemize}
	\item VAR contains "56"
\end{itemize}
\end{frame}

\begin{frame}[fragile]
\frametitle{immediate variable expansion with :=}
\begin{verbatim}
VAR_A = "11"
VAR_B = "B:${VAR_A}"
VAR_A = "22"
VAR_C := "C:${VAR_A}"
VAR_A = "33"
echo ${VAR_A} ${VAR_B} ${VAR_C}
\end{verbatim}
\pause
\begin{itemize}
	\item 33 B:33 C:22
	\item the content of VAR\_C is expanded immediately on assignment
	\item the content of VAR\_B is expanded on use
\end{itemize}
\end{frame}

\begin{frame}[fragile]
\frametitle{append (+=) or prepend (=+) a variable}
\begin{verbatim}
VAR_A = "12"
VAR_A += "34"
VAR_B = "56"
VAR_B =+ "78"
\end{verbatim}
\pause
\begin{itemize}
	\item VAR\_A contains "12 34"
	\item VAR\_B contains "78 56"
	\item there are spaces between the appended values
\end{itemize}
\end{frame}

\begin{frame}[fragile]
\frametitle{append (.=) or prepend (=.) a variable}
\begin{verbatim}
VAR_A = "12"
VAR_A .= "34"
VAR_B = "56"
VAR_B =. "78"
\end{verbatim}
\pause
\begin{itemize}
	\item VAR\_A contains "1234"
	\item VAR\_B contains "7856"
	\item there are no spaces between the appended values
\end{itemize}
\end{frame}

\begin{frame}[fragile]
\frametitle{assignment debugging}
\begin{verbatim}
$ echo 'FOO ??= "123"' >> conf/local.conf
$ echo 'FOO ?= "456"' >> conf/local.conf

$ bitbake -e | grep FOO
# $FOO [2 operations]
FOO="456"
\end{verbatim}
\end{frame}

\subsection{Recipes}
\begin{frame}
\frametitle{typical progressing}
\begin{enumerate}
\item fetch source files
\pause
\item extract sources
\pause
\item patch sources
\pause
\item configure sources
\pause
\item compilation
\pause
\item packaging
\end{enumerate}
\end{frame}

\begin{frame}[fragile]
\frametitle{skeleton}
\begin{verbatim}
SUMMARY = "short description of the package (1 line)"
DESCRIPTION = "a long version of the description of the package"
HOMEPAGE = "http://url-of-the-os-project.org"
LICENSE = "LGPLv2.1"

LIC_FILES_CHKSUM = "file://COPYING;md5=xxxx \
                    file://licfile1.txt;beginline=5;endline=29;md5=yyyy \
                    file://licfile2.txt;endline=50;md5=zzzz

SRC_URI = "file://mysw-1.0.tbz"
SRC_URI[md5sum] = "xxx"
SRC_URI[sha256sum] = "yyy"

S = "${WORKDIR}/${PN}-${PV}"

inherit autotools
\end{verbatim}
\end{frame}

\begin{frame}
\frametitle{syntax}
a recipe normaly consists of a human readable description of the project and
references to the open-source project and:
\pause
\begin{description}
\item[LIC*] reference to the used licenses
\pause
\item[SRC\_URI] list of source files (local or remote)
\pause
\item[PV] package-version (retrived from filename name\_version.bb)
\pause
\item[PN] package-name (retrived from filename name\_version.bb)
\pause
\item[P] ${PN}-${PV}
\pause
\item[S] The location in the Build Directory where unpacked recipe source code resides.
\pause
\item[inherit] use a class (or multiple classes)
\end{description}
\end{frame}

\begin{frame}
\frametitle{the LICENSE variable}
list of source licenses for the recipe:
\begin{itemize}
\item do not use spaces within individual license names
\pause
\item use spaces between license names
\pause
\item separate license names using | (pipe) when there is a choice between
 licenses
\pause
\item separate license names using \& (AND) if parts of the code are licensed
 with different licenses
\pause
\item for standard licenses, use the names of the files in
 meta/files/common-licenses/ or the SPDXLICENSEMAP
 \footnote{aps commonly used license names to their SPDX counterparts found in
 meta/files/common-licenses/. For the default SPDXLICENSEMAP mappings, see the
 meta/conf/licenses.conf file}
 flag names defined in meta/conf/licenses.conf
\pause
\item use "CLOSED" for closed source software
 (LIC\_FILES\_CHKSUM is not needed to be defined then)
\end{itemize}
\end{frame}

\begin{frame}
\frametitle{LIC\_FILE\_CHKSUM variable}
Checksums of the license text in the recipe source code.
\pause
\vspace{2em}


This variable tracks changes in license text of the source code files.
If the license text is changed, it will trigger a build failure,
which gives the developer an opportunity to review any license change.
\end{frame}

\begin{frame}[fragile]
\frametitle{SRC\_URI variable}
\begin{verbatim}
SRC_URI = "<protocol>://<host>/<path>;<OptionA=xxx>;<OptionB=xxx>"
\end{verbatim}
\pause
multiple urls can be set in a SRC\_URI variable:
\begin{verbatim}
SRC_URI = "<url1>;name=url1 <url2>;name=url2"
\end{verbatim}
\pause
for each url a md5 and sha256 checksum needs to be added:
\begin{verbatim}
SRC_URI[url1.md5sum] = xxx
SRC_URI[url1.sha256sum] = yyy
SRC_URI[url2.md5sum] = zzz
SRC_URI[url2.sha256sum] = xyz
\end{verbatim}
\pause
To get these checksums don't specify them and run a build and copy them from
the error message. (Don't use md5sum or sha256sum on the commandline; they
produce a different checksum.)
\end{frame}

\begin{frame}
\frametitle{local SRC\_URI (file://)}
The path is relative to the FILESPATH variable. To modify the FILESPATH use
FILESEXTRAPATH.
\pause
\vspace{2em}


Additional files are searched in subdirectories of the directory in which the
recipe file (.bb) or append file (.bbappend) resides:
\begin{description}
\item[\${BPN}] base recipe name without any special suffix or version numbers.
\pause
\item[\${BP} - \${BPN}-\${PV}] base recipe name and version but without any special package name suffix.
\pause
\item[files] files within a directory, which is named files and is also alongside the recipe or append file. 
\end{description}
\end{frame}

\begin{frame}
\frametitle{the BPN variable}
\begin{itemize}
\item bare name of the recipe
\pause
\item version of PN but without suffixes specified in SPECIAL\_PKGSUFFIX
  (-common, -native, -cross)
\pause
\item version of PN but without prefixes specified in MLPREFIX (lib64-, lib32-)
\end{itemize}
\end{frame}

\begin{frame}
\frametitle{remote SRC\_URI}
\begin{description}
\item[bzr://]Bazaar revision control repository
\pause
\item[git://]Git revision control repository
\pause
\item[osc://]OSC (OpenSUSE Build service) revision control repository
\pause
\item[ccrc://]ClearCase repository
\pause
\item[http://]Internet using http
\pause
\item[https://]Internet using https
\pause
\item[ftp://]Internet using ftp
\pause
\item[cvs://]CVS revision control repository
\pause
\item[hg://]Mercurial (hg) revision control repository
\pause
\item[p4://]Perforce (p4) revision control repository
\pause
\item[ssh://]secure shell
\pause
\item[svn://]Subversion (svn) revision control repository
\end{description}
\end{frame}

\begin{frame}
\frametitle{SRC\_URI patch options}
standard options
\begin{description}
\item[apply=no] apply patch or not; default is yes
\pause
\item[striplevel=0] striplevel to use when applying a patch; default is 1
\pause
\item[patchdir=\${S}/foo] directory in which the patch should be applied;
 default is \${S}
\end{description}

\end{frame}
\begin{frame}
\frametitle{SRC\_URI patch options \#2}
specific options
\begin{description}
\item[mindate] apply patch only if SRCDATE
 \footnote{The date of the source code used to build the package.
 This variable applies only if the source was fetched from a
 Source Code Manager (SCM)} is equal to or greater than mindate
\pause
\item[maxdate] apply patch only if SRCDATE is not later than maxdate
\pause
\item[minrev] apply the patch only if SRCREV
 \footnote{The revision of the source code used to build the package.
 This variable applies to Subversion, Git, Mercurial and Bazaar only}
 is equal to or greater than minrev
\item[maxrev] apply patch only if SRCREV is not later than maxrev
\pause
\item[rev] apply patch only if SRCREV is equal to rev
\pause
\item[notrev] apply patch only if SRCREV is not equal to rev
\end{description}
\end{frame}

\begin{frame}
\frametitle{SRC\_URI options}
\begin{description}
\item[unpack=no] controls if an archive is unpacked; default is yes
\pause
\item[subdir=bla] places the file (or extracts its contents) into the
 specified subdirectory of WORKDIR
 \footnote{${TMPDIR}/work/${MULTIMACH\_TARGET\_SYS}/${PN}/${EXTENDPE}${PV}-${PR}; 
 eg. poky/build/tmp/work/qemux86-poky-linux/foo/1.3.0-r0}
\item[name=mydl] name to be used for association with SRC\_URI checksums when
 you have more than one file specified in SRC\_URI
\pause
\item[downloadfilename=my.tar.gz] the filename used when storing the downloaded file
\end{description}
\end{frame}

\begin{frame}
\frametitle{inherit}
inherit is used to use the functionality defined in a .bblcass file. Popular
predefined classes are:
\begin{itemize}
\item allarch
\item archiver
\item autotools / autotools-brokensep
\item bin\_package
\item cmake
\item cpan
\item distutils / setuptools
\item kernel / module
\item mime
\item qmake / qmake2
\item qt4e / qt4x11
\item scons
\item systemd
\item u-boot
\item vala
\end{itemize}
\end{frame}

\subsection{Append files}
\begin{frame}
\frametitle{basics}
\begin{itemize}
	\item are typically used to modify or extend the functionality of the base
		recipe
\pause
	\item it's recommended by the Yocto project to use bbappend files instead
		of copying and modyfiing a recipe in an own layer
\end{itemize}
\end{frame}

\begin{frame}[fragile]
\frametitle{naming}
an append file must be named after the base package:
\begin{verbatim}
<base-pn>\_<base-pv>.bbappend
\end{verbatim}
\pause
<base-pv> can be replaced by \% to match all versions.
\end{frame}

\subsection{Classes}
\begin{frame}
\frametitle{basics}
\begin{itemize}
	\item python can be used to write functions
\pause
	\item there should be no need to write a own class
\end{itemize}
\end{frame}

\subsection{Tasks}
\begin{frame}
\frametitle{basics}
\begin{itemize}
	\item are defined and ordered in classes
	\item can be overriden by classes and recipes
\end{itemize}
\end{frame}

\begin{frame}
	\frametitle{download \& patch}
\begin{description}
\item [do\_checkuri] validates the SRC\_URI value
\pause
\item [do\_checkuriall] validates the SRC\_URI value for all recipes required
	to build a target"
\pause
\item [do\_fetch] fetches the source code
\pause
\item [do\_fetchall] fetches all remote sources required to build a target
\pause
\item [do\_unpack] unpacks the source code into a working directory
\pause
\item [do\_patch] locates patch files and applies them to the source code
\end{description}
\end{frame}

\begin{frame}
	\frametitle{configue \& compile}
\begin{description}
\item [do\_configure] configures the source by enabling and disabling any
	build-time and configuration options for the software being built
\pause
\item [do\_configure\_ptest\_base] configures the runtime test suite included
	in the software being built
\pause
\item [do\_compile] compiles the source in the compilation directory
\pause
\item [do\_install] copies files from the compilation directory to a holding
	area
\pause
\item [do\_populate\_sysroot] copies a subset of files installed by
	do\_install into the sysroot in order to make them available to other
	recipes
\end{description}
\end{frame}

\begin{frame}
\frametitle{packaging}
\begin{description}
\item [do\_packagedata] creates package metadata used by the build system to
	generate the final packages
\pause
\item [do\_package] analyzes the content of the holding area and splits it
	into subsets based on available packages and files
\pause
\item [do\_package\_write] creates the actual packages and places them in the
	Package Feed area
\pause
\item [do\_package\_write\_deb] creates the actual DEB packages and places
	them in the Package Feed area
\pause
\item [do\_package\_write\_ipk] creates the actual IPK packages and places
	them in the Package Feed area
\pause
\item [do\_package\_write\_rpm] creates the actual RPM packages and places
	them in the Package Feed area
\pause
\item [do\_package\_write\_tar] creates tar archives for packages and places
	them in the Package Feed area
\pause
\item [do\_package\_index] creates or updates the index in the Package Feed
	area
\end{description}
\end{frame}

\begin{frame}
	\frametitle{deploy}
\begin{description}
\item [do\_rootfs] creates the root filesystem (file and directory structure)
	for an image
\pause
\item [do\_vmdkimg] creates a .vmdk image for use with VMware and compatible
	virtual machine hosts"
\pause
\item [do\_deploy] writes deployable output files to the deploy directory
\pause
\item [do\_populate\_sdk] creates the file and directory structure for an
	installable SDK
\end{description}
\end{frame}

\begin{frame}
\frametitle{cleanup}
\begin{description}
\item [do\_clean] removes all output files for a target
\pause
\item [do\_cleanall] removes all output files, shared state cache, and
	downloaded source files for a target
\pause
\item [do\_cleansstate] removes all output files and shared state cache for a
	target
\pause
\item [do\_rm\_work] removes work files after the build system has finished
	with them
\pause
\item [do\_rm\_work\_all] top-level task for removing work files after the
	build system has finished with them
\end{description}
\end{frame}

\begin{frame}
\frametitle{kernel}
\begin{description}
\item [do\_kernel\_checkout] checks out source/meta branches for a linux-yocto
	style kernel
\pause
\item [do\_validate\_branches] ensures that the source/meta branches are on
	the locations specified by their SRCREV values for a linux-yocto style
	kernel"
\pause
\item [do\_kernel\_configme] assembles the kernel configuration for a
	linux-yocto style kernel
\pause
\item [do\_menuconfig] runs 'make menuconfig' for the kernel
\pause
\item [do\_diffconfig] compares the old and new config files after running
	do\_menuconfig for the kernel
\pause
\item [do\_savedefconfig] creates a minimal Linux kernel configuration file
\pause
\item [do\_kernel\_configcheck] validates the kernel configuration for a
	linux-yocto style kernel
\pause
\item [do\_sizecheck] checks the size of the kernel image against
	KERNEL\_IMAGE\_MAXSIZE (if set)
\end{description}
\end{frame}

\begin{frame}
\frametitle{kernel}
\begin{description}
\item [do\_compile\_kernelmodules] compiles loadable modules for the Linux
	kernel
\pause
\item [do\_strip] strips unneeded sections out of the Linux kernel image
\pause
\item [do\_kernel\_link\_vmlinux] creates a symbolic link in arch/\$arch/boot
	for vmlinux kernel images
\pause
\item [do\_bundle\_initramfs] combines an initial ramdisk image and kernel
	together to form a single image
\end{description}
\end{frame}

\begin{frame}
\frametitle{tests}
\begin{description}
\item [do\_compile\_ptest\_base] compiles the runtime test suite included in
	the software being built
\pause
\item [do\_install\_ptest\_base] copies the runtime test suite files from the
	compilation directory to a holding area
\pause
\item [do\_testimage] boots an image and performs runtime tests within the
	image
\pause
\item [do\_testimage\_auto] boots an image and performs runtime tests within
	the image immediately after it has been built
\end{description}
\end{frame}

\begin{frame}
\frametitle{licenses}
\begin{description}
\item [do\_populate\_lic] writes license information for the recipe that is
	collected later when the image is constructed
\pause
\item [do\_spdx] a build stage that takes the source code and scans it on a
	remote FOSSOLOGY server in order to produce an SPDX document
\end{description}
\end{frame}

\begin{frame}
\frametitle{special stuff}
\begin{description}
\item [do\_uboot\_mkimage] creates a uImage file from the kernel for the
	U-Boot bootloader
\pause
\item [do\_generate\_qt\_config\_file] writes a qt.conf file for building a
	Qt-based application
\pause
\item [do\_devshell] starts a shell with the environment set up for
	development/debugging
\pause
\item [do\_listtasks] lists all defined tasks for a target
\end{description}
\end{frame}

\subsection{Machines}
\begin{frame}
\frametitle{basics}
a machine config is used to describe a board
\begin{itemize}
	\item machine configs are stored in the layers: conf/machine/*
\pause
	\item settings can be splitted in different include *.inc files
\pause
	\item e.g. one include for CPU that is used by the SoC inc file,
that is used by the Board .conf file
\pause
	\item the include files can be stored in different layers
\end{itemize}
\end{frame}

\begin{frame}
	\frametitle{u-boot \& kernel}
\begin{description}
	\item [UBOOT\_MACHINE] value passed on the make command line when building a
		U-Boot image
\pause
	\item [UBOOT\_MAKE\_TARGET] target called in the Makefile
\pause
	\item [UBOOT\_ENTRYPOINT] entry point for the U-Boot image
\pause
	\item [PREFERRED\_PROVIDER\_virtual/kernel] default kernel
\pause
	\item [KERNEL\_DEVICETREE] default devicetree
\pause
	\item [KERNEL\_IMAGETYPE] type of kernel to build for a device,
		defaults to 'zImage'
\end{description}
\end{frame}

\begin{frame}
	\frametitle{hardware}
\begin{description}
	\item[SOC\_FAMILY] groups together machines based upon the same family of SOC
		(System On Chip)
\pause
	\item [MACHINEOVERRIDES] lists overrides specific to the current machine.
		By default, this list includes the value of MACHINE. This can be used in
		recipes; e.g. MACHINEOVERRIDES =. "mymachine" and in the recipe
		SRC\_URI\_append\_mymachine = "file://mymachine-quirk.patch"
\pause
	\item [MACHINE\_FEATURES] list of hardware features the MACHINE supports
		\footnote{acpi, alsa, apm, bluetooth, ext2, irda, keyboard, pci, pcmcia,
		screen, serial, touchscreen, usbgadget, usbhost, wifi}
\pause
	\item [MACHINE\_EXTRA\_RRECOMMENDS] list of machine-specific packages to
		install as part of the image being built that are not essential for booting
		the machine. The image being built has no build dependencies on the packages
		in this list.
\pause
\item [SERIAL\_CONSOLE] speed and device for the serial port used to attach
		the serial console. This variable is given to the kernel as the 'console'
		parameter. After booting occurs, getty is started on that port so remote
		login is possible.
	\end{description}
\end{frame}

\begin{frame}
\frametitle{compiler settings}
\begin{description}
\item [DEFAULTTUNE] e.g. armv6hf or cortexa8hf-neon, x86-64, \dots
\pause
\item [TUNE\_FEATURES] e.g. "armv7a vfp neon"
\pause
\item [TUNEVALID] Descriptions, stored as flags, of valid tuning features
\pause
\item [TUNECONFLICTS] list of conflicting features for a given feature
\end{description}
\end{frame}

\begin{frame}
\frametitle{software}
\begin{description}
\item [PREFERRED\_VERSION\_xserver-xorg] compatible xserver version
\pause
\item [PREFERRED\_PROVIDER\_virtual/kernel] recommended kernel
\pause
\item [IMAGE\_FSTYPES] formats for the rootfs, e.g. "ext3 tar.bz2"
\pause
\item [IMAGE\_CLASSES] list of classes that all images should inherit, default
		is image\_types
\end{description}
\end{frame}

\subsection{Images}
\begin{frame}
\frametitle{basics}
\begin{itemize}
\item images are constructed using the packages built earlier and put into the
	Package Feeds
\pause
\item decisions of what to install on the image is based on the minimum
	defined set of required components in an image recipe
\pause
\item this minimum set is then expanded based on dependencies to produce a
	package solution
\pause
\item variety of formats (tar.bz2, ext2, ext3, jffs, \dots) are supported
\end{itemize}
\end{frame}

\begin{frame}[fragile]
\frametitle{prepare environment}
\begin{itemize}
\item bitbake is typically not installed into regular search paths
\pause
\item the environment of the bash is modified to find the commands
\pause
\item non-bash shells are not supported
\end{itemize}
\pause
\begin{verbatim}
% . ./oe-init-buildenv <builddir>
\end{verbatim}
\begin{itemize}
\item is used to modify the environment and change the CWD to <builddir>
\item ./oe-init-buildenv-memres is used to keep the bitbake-server running
\end{itemize}
\end{frame}

\begin{frame}[fragile]
\frametitle{build a predefined image}
\begin{verbatim}
% bitbake core-image-minimal
\end{verbatim}
\end{frame}

\begin{frame}[fragile]
\frametitle{start the image}
\begin{verbatim}
% runqemu qemux86 core-image-minimal
\end{verbatim}
\end{frame}

\begin{frame}[fragile]
\frametitle{inspect the build}
\begin{verbatim}
tmp/
├── buildstats
├── cache
├── deploy
├── log
├── sstate-control
├── stamps
├── sysroots
├── work
└── work-shared
\end{verbatim}
\end{frame}

\begin{frame}[fragile]
\frametitle{inspect the build}
\begin{verbatim}
tmp/buildstats/core-image-minimal-qemux86/201408271416/
├── acl-2.2.52-r0
├── acl-native-2.2.52-r0
├── alsa-lib-native-1.0.27.2-r0
├── attr-2.4.47-r0
├── attr-native-2.4.47-r0
├── autoconf-native-2.69-r11
...
\end{verbatim}
\end{frame}

\begin{frame}[fragile]
\frametitle{inspect the build}
\begin{verbatim}
tmp/buildstats/core-image-minimal-qemux86/201408271416/acl-2.2.52-r0/
├── do_compile
├── do_compile_ptest_base
├── do_configure
├── do_configure_ptest_base
├── do_fetch
├── do_install
├── do_install_ptest_base
├── do_package
├── do_packagedata
├── do_package_write_rpm
├── do_patch
├── do_populate_lic
├── do_populate_sysroot
└── do_unpack
\end{verbatim}
\end{frame}

\begin{frame}[fragile]
\frametitle{inspect the build}
\begin{verbatim}
408271416/acl-2.2.52-r0/do_unpack
Event: TaskStarted
Started: 1409143746.65
acl-2.2.52-r0: do_unpack: Elapsed time: 0.22 seconds
CPU usage: 7.1%
EndIOinProgress: 0
EndReadsComp: 973062
EndReadsMerged: 543875573
EndSectRead: 36860156
EndSectWrite: 1158945211
EndTimeIO: 30104972
EndTimeReads: 5545878
EndTimeWrite: 1455538600
...
StartWritesComp: 12202741
Status: PASSED
Ended: 1409143746.87
\end{verbatim}
\end{frame}

\begin{frame}[fragile]
\frametitle{inspect the build}
\begin{verbatim}
tmp/
├── buildstats
├── cache
├── deploy
├── log
├── sstate-control
├── stamps
├── sysroots
├── work
└── work-shared
\end{verbatim}
\end{frame}

\begin{frame}[fragile]
\frametitle{inspect the build}
\begin{verbatim}
tmp/deploy/
├── images
│   └── qemux86
│       ├── bzImage -> bzImage--3.14+git0+09424...
│       ├── core-image-minimal-qemux86-20140827121546.rootfs.ext3
│       ├── core-image-minimal-qemux86-20140827121546.rootfs.manifest
│       ├── core-image-minimal-qemux86-20140827121546.rootfs.tar.bz2
│       ├── core-image-minimal-qemux86.ext3 -> core-image...
│       ├── ...
\end{verbatim}
\end{frame}

\begin{frame}[fragile]
\frametitle{inspect the build}
\begin{verbatim}
tmp/deploy/
├── licenses
│   ├── acl
│   │   ├── COPYING
│   │   ├── COPYING.LGPL
│   │   ├── generic_GPLv2
│   │   └── generic_LGPLv2.1
│   ├── acl-native
│   ├── alsa-lib-native
│   ├── apr-native
│   ├── ..
\end{verbatim}
\end{frame}

\begin{frame}[fragile]
\frametitle{inspect the build}
\begin{verbatim}
tmp/deploy/
└── rpm
    ├── all
    │   ├── packagegroup-core-standalone-sdk-target-1.0-r8.all.rpm
    │   ├── packagegroup-core-standalone-sdk-target-dbg-1.0-r8.all.rpm
    │   ├── packagegroup-core-standalone-sdk-target-dev-1.0-r8.all.rpm
    │   ├── repodata
    │   ├── run-postinsts-1.0-r9.all.rpm
    │   ├── ...
    ├── i586
    ├── qemux86
    └── x86_64_nativesdk
\end{verbatim}
\end{frame}

\begin{frame}[fragile]
\frametitle{inspect the build}
\begin{verbatim}
tmp/
...
├── log/cooker/qemux86/20140827121546.log
\end{verbatim}
\pause
\begin{verbatim}
├── sstate-control/manifest-<pn>.<task>
|    /home/local/src/poky/build2/tmp/sysroots/x86_64-linux/usr/include/zconf.h
|    /home/local/src/poky/build2/tmp/sysroots/x86_64-linux/usr/include/zlib.h
|    /home/local/src/poky/build2/tmp/sysroots/x86_64-linux/usr/lib/libz.so.1
\end{verbatim}
\pause
\begin{verbatim}
├── stamps    # cache files
├── sysroots  # for the differnet architectures
\end{verbatim}
\pause
\begin{verbatim}
├── work      # work directories / where the sources are built
|     % ls tmp/work/qemux86-poky-linux/linux-yocto/3.14+gitAUTOINC+0942...
|    deploy-linux-yocto  linux                         packages-split
|    deploy-rpms         linux-qemux86-standard-build  pkgdata
|    image               linux-yocto.spec              pseudo
|    license-destdir     package                       sysroot-destdir
|    temp
\end{verbatim}
\end{frame}

\begin{frame}[fragile]
\frametitle{inspect the build}
\begin{verbatim}
tmp/
└── work-shared
\end{verbatim}
For efficiency, the OpenEmbedded build system creates and uses this directory
to hold recipes that share a work directory with other recipes.


\vspace{2em}
In practice, this is only used for gcc and its variants.
\end{frame}

\begin{frame}[fragile]
\frametitle{inspect the build}
\begin{verbatim}
downloads/
\end{verbatim}
all fetched source tarballs
\end{frame}

\begin{frame}[fragile]
\frametitle{execute a specific task}
\begin{verbatim}
bitbake <recipe> -c <task
\end{verbatim}
\end{frame}

\begin{frame}[fragile]
\frametitle{build dependencies}
dependency graphs (sucks because they're really huge)
\begin{verbatim}
bitbake -g <target>
\end{verbatim}
\pause
dependency explorer
\begin{verbatim}
bitbake -g -u depexp <target>
\end{verbatim}
\end{frame}

\begin{frame}[fragile]
\frametitle{developer shell}
\begin{verbatim}
bitbake <recipe> -c devshell
\end{verbatim}
use ./configure and make to debug build issues
\end{frame}

\begin{frame}[fragile]
\frametitle{inspect builds using toaster}
start toaster web application
\begin{verbatim}
poky/build % source toaster start
\end{verbatim}
\pause
run bitbake

\vspace{2em}
\pause
use 'http://localhost:8000' to browse through the build informations
\pause
\begin{verbatim}
poky/build % source toaster stop
\end{verbatim}
is used to stop toaster (only one toaster per pc possible)
\vspace{2em}
\pause

only actions between toaster start and stop are recorded
\end{frame}

\begin{frame}[fragile]
\frametitle{cleanup}
\begin{verbatim}
% bitbake -c core-image-minimal
\end{verbatim}
\pause
\begin{itemize}
\item doesn't cleanup dependencies
\item doesn't remove deployed files
\item triggers repackaging of all packages
\end{itemize}


\vspace{2em}
\pause
To start from scratch backup the conf directory
and remove everything from build.
\end{frame}

\begin{frame}[fragile]
\frametitle{cleanup}
\begin{verbatim}
% bitbake -c clean xserver-nodm-init
\end{verbatim}
\pause
\begin{itemize}
\item doesn't cleanup dependencies
\item removes deployed files
\item removes downloaded files
\item removes data from work and sysroot directory
\item doesn't remove data from sstate
\item triggers nothing, files from sstate are used
\end{itemize}
\end{frame}

\begin{frame}[fragile]
\frametitle{cleanup}
\begin{verbatim}
% bitbake -c cleanall xserver-nodm-init
\end{verbatim}
\pause
\begin{itemize}
\item doesn't cleanup dependencies
\item removes deployed files
\item removes downloaded files
\item removes data from work and sysroot directory
\item removes data from sstate
\item triggers fetch, compilation and packaging of the component
\end{itemize}
\end{frame}

\begin{frame}[fragile]
\frametitle{force recompilation}
\begin{verbatim}
% bitbake -f -c compile xserver-nodm-init
\end{verbatim}
\begin{itemize}
\item changes are not in the image
\item and not in the package
\end{itemize}
\end{frame}

\subsection{ADT}
\begin{frame}
\frametitle{Yocto ADT (Application Development Kit}
Core Components
\vspace{2em}
\begin{itemize}
\item System Root
\item QEMU Emulator
\item Cross Development Toolchain
\end{itemize}
\end{frame}

\begin{frame}
\frametitle{Yocto ADT}
Eclipse Plugin
\vspace{2em}
\begin{itemize}
\item Roundtrip Application Development
\item Toolchain/System Root Integration
\item Emulated and Hardware Targets
\item Application Templates
\item On-target Debugging
\end{itemize}
\end{frame}

\begin{frame}
\frametitle{Yocto ADT}
Profiling Tools
\vspace{2em}
\begin{itemize}
\item LatencyTOP
\item PowerTOP
\item OProfile
\item Perf
\item SystemTap
\item Lttng-ust
\end{itemize}
\end{frame}

\begin{frame}[fragile]
\frametitle{build a external usable toolchain}
\begin{verbatim}
poky/build % bitbake meta-toolchain
\end{verbatim}
\vspace{2em}
\pause
to install the toolchain:
\begin{verbatim}
% ./tmp/deploy/sdk/poky-eglibc-x86\_64-meta-toolchain-i586-toolchain-1.6.1.sh
Enter target directory for SDK (default: /opt/poky/1.6.1): /home/devel/sdk
\end{verbatim}
\pause
to use the toolchain:
\begin{verbatim}
source /home/local/sdk/environment-setup-i586-poky-linux
\end{verbatim}
\end{frame}

\begin{frame}[fragile]
\frametitle{build a internal usable toolchain}
\begin{verbatim}
poky/build % bitbake meta-ide-support
\end{verbatim}
\vspace{2em}
\end{frame}

\begin{frame}
\frametitle{export a nfsroot}
\begin{verbatim}
%runqemu-extract-sdk \
tmp/deploy/images/qemux86/core-image-minimal-qemux86.tar.bz2 \
~/sdk/core-image-minimal
\end{verbatim}
\end{frame}

\begin{frame}[fragile]
\frametitle{build ADT installer script}
\begin{verbatim}
poky/build % bitbake adt-installer
poky/build % cp tmp/deploy/sdk/adt_installer.tar.bz2 ~/
poky/build % cd
% cp tmp/deploy/sdk/adt_installer.tar.bz2 ~/
% tar xjf adt_installer.tar.bz2
% cd adt-installer
\end{verbatim}
\end{frame}

\begin{frame}
\frametitle{configure ADT installer}
general configuration
\begin{description}
\item[YOCTOADT\_REPO] http repo with rootfs images and ipkg packages.
	Needs to match the layout from 'http://adtrepo.yoctoproject.org'
\pause
\item[YOCTOADT\_TARGETS] machine target architectures to setup cross SDKs
\pause
\item[YOCTOADT\_QEMU] install qemu? \[Y/N\]
\pause
\item[YOCTOADT\_NFS\_UTIL] needed for eclipse \[Y/N\]
\end{description}
\end{frame}

\begin{frame}
\frametitle{configure ADT installer \#2}
configuration for each supported BSP
\begin{description}
\item[YOCTOADT\_TARGET\_MACHINE\_<arch>] qemu that should be used, e.g. qemux86
\pause
\item[YOCTOADT\_ROOTFS\_<arch>] rfs images that should be used, e.g. sato-sdk
\pause
\item[YOCTOADT\_TARGET\_SYSROOT\_<arch>] needs to match above variable
\pause
\item[YOCTOADT\_TARGET\_SYSROOT\_LOC\_<arch>] path where the sysroot will be
	stored
\end{description}
\end{frame}

\begin{frame}[fragile]
\frametitle{run ADT installer}
\begin{verbatim}
adt-installer % ./adt_installer
Please enter the install location (default: /opt/poky/1.6.1): <return>
...
[ADT_INST] Please enter your selections here:
S<return>
...
\end{verbatim}
\pause
to use the ADT, the environment needs to be sourced:
\begin{verbatim}
% .  /opt/poky/1.6.1/environment-setup-i586-poky-linux
\end{verbatim}
\end{frame}

\begin{frame}[fragile]
\frametitle{ADT \& Eclipse}
only supported eclipse releases: kepler \& juno


\vspace{2em}
install and start eclipse:
\begin{verbatim}
% wget http://ftp.fau.de/eclipse/technology/epp/downloads/release/kepler/R/eclipse-cpp-kepler-R-linux-gtk.tar.gz
% tar xzf eclipse-*.tar.gz
% ./eclipse/eclipse
\end{verbatim}
\pause
add the yocto update-site (Help, Install New Software, Add\dots)
\begin{verbatim}
http://downloads.yoctoproject.org/releases/eclipse-plugin/1.6/kepler/
\end{verbatim}
select and install all components, by clicking
'Next, Next, Accept Licenses, Finish, Accept installing from insecure source,
and accept to restart eclipse'
\pause
goto 'Help, Install New Software, Add\dots' again and
select 'Kepler' as update site and select 'Linux Tools' and
'Mobile and Device Development'; select 'Next' until you can
'Finish' and quit eclipse
\end{frame}

\begin{frame}
\frametitle{configure Eclipse}
\begin{itemize}
	\item select 'Window, Preferences, Yocto Project ADT'
	\item select 'Standalone pre-built toolchain'
	\item set Toolchain Root Location '/home/devel/src/poky/build'
	\item set Sysroot Location '/home/devel/poky/build/tmp/sysroots/qemux86'
	\item use 'QEMU' as 'Target Options'
	\item set Kernel to
		'/home/devel/adt-installer/download\_image/bzImage-qemux86.bin'
	\item 'Apply' the Settings and close the dialog with 'OK'
\end{itemize}
\end{frame}

\begin{frame}
\frametitle{Hello World example}
\begin{itemize}
	\item select 'File, New, Project\dots'
	\item select 'C/C++, C Project'
	\item select 'Yocto Project ADT Autotools Project, Hello World ANSI C Project'
	\item enter a 'Project name' and select 'Next'
	\item enter 'Basic settings' and select 'Finish'
	\item if opened, close the 'Welcome' window
	\item right click on the root project folder and select 'Reconfigure Project'
	\item right click on the root project folder and select 'Build Project'
\end{itemize}
\end{frame}

\begin{frame}
\frametitle{start qemu}
\begin{itemize}
	\item select 'Run, External Tools, External Tools Configurations\dots'
	\item select 'Program, qemu\_i586-poky'
	\item edit the arguments that they match:
\begin{verbatim}
-e "source /opt/poky/1.6.1/environment-setup-i586-poky-
linux;runqemu qemux86 /home/local/adt-installer/download_image/
bzImage-qemux86.bin /home/local/sdk/core-image-minimal ;bash"
\end{verbatim}
	\item select 'Apply, Run'
\end{itemize}
Attention! This starts a NFS Server on a user port that listens on all network
interfaces of the PC
\end{frame}

\begin{frame}
\frametitle{remote execution and debugging}
\begin{itemize}
	\item seems to be broken at the moment, or works different than documented
	\item it should be possible, if ssh is added to the image and an ssh
		remote connection will be used.
\end{itemize}
\end{frame}

\input{tailpres}