Using OpenEmbedded

A brief overview of the
scope and issues
involved with building your own
GNU/Linux-based distributions.
Trevor Woerner
trevor@toganlabs.com
Using OpenEmbeddedAn Introduction To Building Your Own Distributions

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March 10, 2019
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Trevor Woerner
●
Senior Software Developer @
Togán Labs
●
Embedded Linux development
and consulting
●
Specialize in OpenEmbedded
●
Strong open-source focus

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Why?

SCaLE 17x
March 10, 2019
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why create your own distribution?
●
very difficult to answer for (casual) user
●
easier to answer when building products
●
tight control over installed software
●
tight control over versions of installed software
●
security
●
software updates
●
device lifetime, multiple devices

SCaLE 17x
March 10, 2019
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Code Choices

SCaLE 17x
March 10, 2019
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booting GNU/Linux
a
press power
button
bootloader kernel boot init system
display
manager /
login screen
window
manager
gui
display server
protocol
desktop
environment
text
START

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March 10, 2019
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in a GNU/Linux system,
only this is "Linux"
kernel boot

SCaLE 17x
March 10, 2019
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booting GNU/Linux - drilling down
bootloader
●
grub
●
u-boot
●
lilo
●
syslinux
●
systemd-boot
●
gummiboot
●
barebox
●
shim

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March 10, 2019
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kernel boot
●
latest kernel.org
●
LTS
●
evil vendor kernel
●
benevolent distro kernel
●
with or without PREEMPT_RT
●
2.6 / 3.x / 4.x
●
xenomai

SCaLE 17x
March 10, 2019
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a
init system
●
sysvinit
●
systemd
●
upstart
●
busybox init
●
OpenRC
●
runit

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March 10, 2019
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display server
protocol
●
X11
●
wayland
●
directfb
●
mir

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March 10, 2019
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display
manager /
login screen
●
XDM
●
GDM
●
KDM
●
LXDM
●
CDM
●
xlogin
●
nodm
●
LightDM

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desktop
environment
●
GNOME
●
KDE
●
LXDE
●
MATE
●
LXQt
●
Enlightenment
●
Cinnamon
●
Unity
●
Xfce

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window
manager
●
Xfwm
●
Openbox
●
KWin
●
i3
●
FVWM
●
TWM
●
compiz
●
Matchbox
●
Metacity
●
Sawfish
●
mwm
●
uwm
●
xmonad
●
ion
●
fluxbox

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March 10, 2019
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NOT booting GNU/Linux - drilling down
●
bash
●
csh
●
tcsh
●
zsh
●
sh
●
ash
●
ksh
●
mosh
●
dsh
Shells
●
gnome-terminal
●
xterm
●
konsole
●
rxvt
●
xfce4-terminal
Terminal
Emulators

SCaLE 17x
March 10, 2019
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●
bash
●
csh
●
tcsh
●
zsh
●
sh
●
ash
●
ksh
●
mosh
●
dsh
Shells
●
gnome-terminal
●
xterm
●
konsole
●
rxvt
●
xfce4-terminal
Terminal
Emulators
●
apache2
●
tomcat
●
jetty
●
lighttpd
●
Nginx
●
cherokee
●
fcgi
●
hiawatha
●
monkey
●
nostromo
Web
Servers
●
chromium
●
firefox
●
links
●
epiphany
●
opic
●
midori
●
konqueror
●
qtwebbrowser
●
rekonq
Web
Browsers

SCaLE 17x
March 10, 2019
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●
bash
●
csh
●
tcsh
●
zsh
●
sh
●
ash
●
ksh
●
mosh
●
dsh
Shells
●
gnome-terminal
●
xterm
●
konsole
●
rxvt
●
xfce4-terminal
Terminal
Emulators
●
apache2
●
tomcat
●
jetty
●
lighttpd
●
Nginx
●
cherokee
●
fcgi
●
hiawatha
●
monkey
●
nostromo
Web
Servers
●
OpenSSH
●
dropbear
SSH
Servers●
coreutils
●
busybox
●
toybox
Basic
Cmdline
Utilities
●
chromium
●
firefox
●
links
●
epiphany
●
opic
●
midori
●
konqueror
●
qtwebbrowser
●
rekonq
Web
Browsers
●
glibc
●
uclibc
●
musl
C
Libraries
●
coreutils
●
busybox
●
toybox
Basic
Cmdline
Utilities ●
gcc
●
llvm
C
Compilers

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●
bash
●
csh
●
tcsh
●
zsh
●
sh
●
ash
●
ksh
●
mosh
●
dsh
Shells
●
gnome-terminal
●
xterm
●
konsole
●
rxvt
●
xfce4-terminal
Terminal
Emulators
●
apache2
●
tomcat
●
jetty
●
lighttpd
●
Nginx
●
cherokee
●
fcgi
●
hiawatha
●
monkey
●
nostromo
Web
Servers
●
OpenSSH
●
dropbear
SSH
Servers●
coreutils
●
busybox
●
toybox
Basic
Cmdline
Utilities
●
db
●
gdbm
●
sqlite
●
hiera
●
metakit
●
mysql
●
postgresql
Databases
●
chromium
●
firefox
●
links
●
epiphany
●
opic
●
midori
●
konqueror
●
qtwebbrowser
●
rekonq
Web
Browsers
●
glibc
●
uclibc
●
musl
C
Libraries
●
coreutils
●
busybox
●
toybox
Basic
Cmdline
Utilities
●
java
●
python
●
go
●
rust
●
nodejs
●
ruby
●
perl
●
mono
●
smalltalk
●
erlang
●
ada
Language
Support
●
gcc
●
llvm
C
Compilers

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March 10, 2019
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●
bash
●
csh
●
tcsh
●
zsh
●
sh
●
ash
●
ksh
●
mosh
●
dsh
Shells
●
gnome-terminal
●
xterm
●
konsole
●
rxvt
●
xfce4-terminal
Terminal
Emulators
●
apache2
●
tomcat
●
jetty
●
lighttpd
●
Nginx
●
cherokee
●
fcgi
●
hiawatha
●
monkey
●
nostromo
Web
Servers
●
OpenSSH
●
dropbear
SSH
Servers●
coreutils
●
busybox
●
toybox
Basic
Cmdline
Utilities
●
db
●
gdbm
●
sqlite
●
hiera
●
metakit
●
mysql
●
postgresql
Databases
●
chromium
●
firefox
●
links
●
epiphany
●
opic
●
midori
●
konqueror
●
qtwebbrowser
●
rekonq
Web
Browsers
●
glibc
●
uclibc
●
musl
C
Libraries
●
coreutils
●
busybox
●
toybox
Basic
Cmdline
Utilities
●
java
●
python
●
go
●
rust
●
nodejs
●
ruby
●
perl
●
mono
●
smalltalk
●
erlang
●
ada
Language
Support
●
gcc
●
llvm
C
Compilers
●
wolfssl
●
tpm/tpm2
●
swupd/swupdate
●
selinux
●
optee
●
ro-rootfs
●
pentesting/kali
Security ●
lxd/lxc
●
docker
●
openstack
●
criu
●
kubernetes
●
kvm
●
oci
●
xen
●
runc
Virtualization

SCaLE 17x
March 10, 2019
20 of 78
●
bash
●
csh
●
tcsh
●
zsh
●
sh
●
ash
●
ksh
●
mosh
●
dsh
Shells
●
gnome-terminal
●
xterm
●
konsole
●
rxvt
●
xfce4-terminal
Terminal
Emulators
●
apache2
●
tomcat
●
jetty
●
lighttpd
●
Nginx
●
cherokee
●
fcgi
●
hiawatha
●
monkey
●
nostromo
Web
Servers
●
OpenSSH
●
dropbear
SSH
Servers●
coreutils
●
busybox
●
toybox
Basic
Cmdline
Utilities
●
db
●
gdbm
●
sqlite
●
hiera
●
metakit
●
mysql
●
postgresql
Databases
●
chromium
●
firefox
●
links
●
epiphany
●
opic
●
midori
●
konqueror
●
qtwebbrowser
●
rekonq
Web
Browsers
●
glibc
●
uclibc
●
musl
C
Libraries
●
coreutils
●
busybox
●
toybox
Basic
Cmdline
Utilities
●
java
●
python
●
go
●
rust
●
nodejs
●
ruby
●
perl
●
mono
●
smalltalk
●
erlang
●
ada
Language
Support
●
gcc
●
llvm
C
Compilers
●
wolfssl
●
tpm/tpm2
●
swupd/swupdate
●
selinux
●
optee
●
ro-rootfs
●
pentesting/kali
Security ●
lxd/lxc
●
docker
●
openstack
●
criu
●
kubernetes
●
kvm
●
oci
●
xen
Virtualization
VER
SIO
N
S

SCaLE 17x
March 10, 2019
21 of 78
●
bash
●
csh
●
tcsh
●
zsh
●
sh
●
ash
●
ksh
●
mosh
●
dsh
Shells
●
gnome-terminal
●
xterm
●
konsole
●
rxvt
●
xfce4-terminal
Terminal
Emulators
●
apache2
●
tomcat
●
jetty
●
lighttpd
●
Nginx
●
cherokee
●
fcgi
●
hiawatha
●
monkey
●
nostromo
Web
Servers
●
OpenSSH
●
dropbear
SSH
Servers●
coreutils
●
busybox
●
toybox
Basic
Cmdline
Utilities
●
db
●
gdbm
●
sqlite
●
hiera
●
metakit
●
mysql
●
postgresql
Databases
●
chromium
●
firefox
●
links
●
epiphany
●
opic
●
midori
●
konqueror
●
qtwebbrowser
●
rekonq
Web
Browsers
●
glibc
●
uclibc
●
musl
C
Libraries
●
coreutils
●
busybox
●
toybox
Basic
Cmdline
Utilities
●
java
●
python
●
go
●
rust
●
nodejs
●
ruby
●
perl
●
mono
●
smalltalk
●
erlang
●
ada
Language
Support
●
gcc
●
llvm
C
Compilers
●
wolfssl
●
tpm/tpm2
●
swupd/swupdate
●
selinux
●
optee
●
ro-rootfs
●
pentesting/kali
Security ●
lxd/lxc
●
docker
●
openstack
●
criu
●
kubernetes
●
kvm
●
oci
●
xen
Virtualization
VER
SIO
N
S
DEPENDENCIES

SCaLE 17x
March 10, 2019
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why "re-invent the wheel" and create alternates of
existing, working projects?
●
code forks due to disagreement in {techincal | legal |
community | leadership | ...} direction
●
real or perceived legal issues
●
re-design in order to
●
add more features
●
support more platforms
●
fundamentally change how something works
(algorithm)

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why "re-invent the wheel" and create alternates of
existing, working projects?
●
to promote "healthy" competition
●
unaware of existing projects
●
original project is abandoned
●
to "start fresh"
●
for the learning experience

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a GNU/Linux system is not one single, monolithic blob
created by one company/organization
●
individual people/groups, working mostly
autonomously
●
rarely a top-level, rigid, overall, pre-developed spec
●
independent release schedules
●
multiple options at every step
●
choosing a cohesive set → DISTRIBUTION
●
one doesn’t slap together a cohesive, working set by
accident

SCaLE 17x
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issues
●
there is no “one correct way” to write (open-source)
software
●
language
●
repository system
●
location
●
licensing
●
(still) not enough developers consider cross-
compilation

SCaLE 17x
March 10, 2019
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solution
●
use an embedded Linux build system
●
PLEASE don’t “roll your own”

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Running Code

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●
processors are the heart of any device
●
all processor families "speak" their own "language"
(sometimes sub-groups within a family have their own
"dialect")
●
a programmer's intentions, eventually, has to be
expressed in the processor's "language"
●
either by compiling/assembling/linking code
●
or by running the code through an interpreter
●
whether we're talking about compiled code, or
interpreted, at some point compiling needs to take
place (compiling of code, compiling of interpreter)

SCaLE 17x
March 10, 2019
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how to compile code
●
fetch code
●
unpack
●
patch
●
configure
●
build/compile
●
stage
●
package

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fetch
●
not always obvious from where to get code
●
interact with a repository (svn, cvs, git, hg, perforce,
clearcase, rcs/sccs, darcs, monotone, GNU bazaar,
MS vss...) or tarball releases (e.g. ftp)
●
interact with a code hosting site (github,
sourceforge, bitbucket, gitlab, launchpad,
cloudforge...)
●
branches, tags
●
verify signature/checksum(s)

SCaLE 17x
March 10, 2019
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unpack
●
compression
●
gzip, bzip2, xz, z, lzo, lzma
●
archive
●
tar, cpio, shar
●
compression + archive
●
7z, zip, arc, apk, tar.{gz|xz|bzip2|...}

SCaLE 17x
March 10, 2019
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patch
●
when you do something (even slightly) different than
what the people who wrote the code are doing,
patches are often needed
●
different compiler
●
different/newer/older host
●
different C library
●
different versions of dependencies
●
sometimes upstream doesn't accept your patch
●
where to store/maintain these patches?

SCaLE 17x
March 10, 2019
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configure
●
enable/disable features
●
build systems
●
make
●
makefile generators
●
autotools
●
cmake
●
pymake
●
"make" replacements
●
ant
●
maven
●
waf
●
ninja
●
gyp/gn
●
meson

SCaLE 17x
March 10, 2019
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build/compile
●
cross-compiling
●
selecting, patching, configuring a cross-compiler
(and C lib) is non-trivial
●
using the cross-compilier is non-trivial (avoiding
host contamination)

SCaLE 17x
March 10, 2019
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stage
●
preparing artifacts for the target
●
packing
●
signing
●
arranging
●
updating/removing
●
only install relevant parts (remove docs, man pages,
include files... unless user wants them explicitly)

SCaLE 17x
March 10, 2019
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package
●
ipk
●
deb
●
rpm

SCaLE 17x
March 10, 2019
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Target
Device

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each device has its own quirks
●
RPi
●
fat + ext partitions
●
config.txt in fat
●
Rockchip
●
multiple partitions, individual chunks per partition
●
all chunks need to run through vendor tool
●
AllWinner
●
special "fex" files (i.e. pre-dt) + script.bin
●
DragonBoard 410c
●
fastboot tools to load eMMC
●
C.H.I.P.
●
special "UBI" image
●
board needs to be in "FEL" mode
●
etc...

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Putting It
Together

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creating a distro
●
choosing amongst 1000's x 1000's of packages,
making sure there's one of each of the required
packages, dependencies, versions, ...
●
preparing the right cross-development tools
●
building (fetching, unpacking, patching, configuring,
cross-compiling, staging, packaging) the software
●
getting that software onto/into the target device in
the proper format

SCaLE 17x
March 10, 2019
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OpenEmbedded

SCaLE 17x
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●
targeting multiple devices!
OpenEmbedded

SCaLE 17x
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OpenEmbedded
●
provides "recipes" for 1000's of packages ~>
2000ish in base layers alone
●
prepares the cross-development tools
●
builds (fetches, unpacks, patches, configures, cross-
compiles, stages, package) the software with a very
sophisticated scheduler with correct dependencies
●
creates an image for the target device in the proper
format
●
targets multiple platforms/devices with small
configuration changes (often a one line change)

SCaLE 17x
March 10, 2019
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OpenEmbedded+
●
has an optional graphical front-end (toaster)
●
optionally integrates into Eclipse
●
can generate image-specific SDK and eSDK
●
the (e)SDK can be used on Linux, Windows, or
MacOS hosts (CROPS)
●
supports many hardware targets (including qemu)
across many architectures (x86, arm, ppc, mips,
riscv) and variants (32bit, 64bit) ~> 600ish

SCaLE 17x
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MinnowBoard/Turbot
●
Intel Atom x86_64
●
Intel Graphics
●
1GB - 2GB DDR3
●
uSD, GbE, USB2/3
●
turbot dual/quad dual-eth
●
meta-intel
$99

SCaLE 17x
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BeagleBoard/Bone
●
TI OMAP3xxx/Sitara AM3xxx
●
Cortex-A8, Cortex-A15
●
PowerVR
●
256MB - 512MB DDR2
●
SD/uSD, 10/100, USB2, PRU
●
BeagleBoard, BeagleBoard-xM,
BeagleBone, BeagleBone
Black, BeagleBoard x15
●
meta-ti
$55

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DragonBoard 410c
●
Qualcomm Snapdragon 410
●
Cortex-A53
●
Adreno 306 → Freedreno
●
2GB DDR3
●
uSD, 8GB eMMC, USB2, WiFi
2.4GHz a/b/g/n, bt 4.1
●
meta-qcom
$75

SCaLE 17x
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C.H.I.P. (i.e. the $9 computer)
●
AllWinner R8
●
Cortex-A8
●
Mali-400
●
512MB DDR3
●
4GB eMMC, USB2, WiFi
2.4GHz a/b/g/n, bt 4.0
●
meta-chip
$9

SCaLE 17x
March 10, 2019
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Creator Ci20
●
MIPS Ingenic JZ4780
●
PowerVR
●
1GB DDR3
●
8GB eMMC, SD, 10/100, USB2,
WiFi 2.4GHz b/g/n, bt 4.0
●
meta-jz-mips
$72

SCaLE 17x
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Odroid C1/C2
●
Amlogic S805/S905
●
ARM Cortex-A5, Cortex-A53
●
Mali-450
●
1GB - 2GB DDR3
●
opt eMMC, uSD, GbE, USB2
●
meta-odroid
$40

SCaLE 17x
March 10, 2019
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Odroid XU3/XU4
●
Samsung Exynos 5 Octa
●
ARM Cortex-A7 + A15
●
Mali-T628
●
2GB DDR3
●
opt eMMC, uSD, 10/100/GbE,
USB2/3
●
meta-odroid
$74

SCaLE 17x
March 10, 2019
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Zybo-Zynq7
●
Xilinx Zynq 7Z007S
●
ARM Cortex-A9
●
512MB DDR3
●
PMOD, uSD, USB2
●
meta-xilinx
$189

SCaLE 17x
March 10, 2019
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Pine64
●
AllWinner A64
●
ARM Cortex-A53
●
Mali-400
●
512MB DDR3
●
uSD, 10/100, USB2
●
meta-pine64
$189

SCaLE 17x
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Firefly-RK3288
●
Rockchip RK3288
●
ARM Cortex-A17
●
Mali-T760
●
2GB - 4GB DDR3
●
16GB eMMC, uSD, GbE, WiFi
a/b/g/n/ac, bt 4.0+ble, USB2
●
meta-rockchip
$129

SCaLE 17x
March 10, 2019
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Wandboard
●
Freescale iMX6
●
ARM Cortex-A9
●
Vivante → Etnaviv
●
1GB DDR3
●
uSD, GbE, WiFi n, USB2
●
solo, dual, quad
●
meta-freescale-3rdparty
$69

SCaLE 17x
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Raspberry Pi
●
Broadcom BCM2835 BCM2836
BCM2837
●
ARM11, Cortex-A7, Cortex-A53
●
Broadcom VC4
●
512MB - 1GB DDR2
●
uSD, 10/100, USB2
●
Rpi A/B, Rpi2, Rpi0, Rpi3,
Rpi3B+
●
meta-raspberrypi
$35

SCaLE 17x
March 10, 2019
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Banana Pi
●
AllWinner A20
●
Cortex-A7
●
Mali-400
●
1GB DDR3
●
SD, GbE, USB2
●
meta-sunxi
$32

SCaLE 17x
March 10, 2019
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Orange Pi
●
AllWinner A20/H2/H3
●
Cortex-A7
●
Mali-400
●
1GB - 2GB DDR3
●
uSD, GbE, USB2
●
meta-sunxi
$25

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March 10, 2019
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OpenEmbedded++
●
runs on most GNU/Linux host distributions (debian,
ubuntu, fedora, centOS, openSUSE)
●
is mostly host-independent (builds it own set of
many native tools)
●
extensive test framework (build tests, package unit-
tests, on-target tests, image/boot tests)
●
license/legal audit or constraint
●
speeds up subsequent builds with sophisticated
sstate cache

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March 10, 2019
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How Does
It Work?

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March 10, 2019
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recipes
●
a file with the necessary data to process a package
classes
●
a grouping of similar functionality
layers
●
a set of related recipes, classes, data for a specific
purpose (BSP, software, distro)
bitbake
●
the tool which runs the whole build
configuration files
●
e.g. conf/local.conf

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sample recipe (openembedded-core/meta/recipes-graphics/mesa/mesa -- abridged)
SUMMARY = "A free implementation of the OpenGL API"
DESCRIPTION = "Mesa is an open-source implementation of the OpenGL specification -
a system for rendering interactive 3D graphics.
A variety of device drivers allows Mesa to be used in many different environments
ranging from software emulation to complete hardware acceleration for modern GPUs.
Mesa is used as part of the overall Direct Rendering Infrastructure and X.org
environment."
HOMEPAGE = "http://mesa3d.org"
BUGTRACKER = "https://bugs.freedesktop.org"
SECTION = "X11"
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://docs/license.html;md5=725f991a1cc322aa7a0cd3a2016621c4"
DEPENDS = "expat makedepend-native zlib"
PROVIDES = "virtual/libgl virtual/libgles1 virtual/libgles2 virtual/egl"
inherit autotools pkgconfig python3native gettext distro_features_check
PACKAGECONFIG ??= "x11 dri3"
PACKAGECONFIG[dri3] = "--enable-dri3,--disable-dri3,dri3proto presentproto libxshmfence"
SRC_URI = "https://mesa.freedesktop.org/archive/mesa-${PV}.tar.xz
file://disable-asm-on-non-gcc.patch"
SRC_URI[md5sum] = "203d1a79156ab6926f2d253b377e9d9d"
SRC_URI[sha256sum] = "8f9d9bf281c48e4a8f5228816577263b4c655248dc7666e75034ab422951a6b1"

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preamble
environment."
SECTION = "X11"
LICENSE = "MIT"

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March 10, 2019
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license
environment."
SECTION = "X11"
LICENSE = "MIT"

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alternates of same purpose
environment."
SECTION = "X11"
LICENSE = "MIT"

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adding classes of known functionality
environment."
SECTION = "X11"
LICENSE = "MIT"

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March 10, 2019
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configuration options
environment."
SECTION = "X11"
LICENSE = "MIT"

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March 10, 2019
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dependencies (build and native)
environment."
SECTION = "X11"
LICENSE = "MIT"

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March 10, 2019
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fetch: location, patch, signature verification
environment."
SECTION = "X11"
LICENSE = "MIT"

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March 10, 2019
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layers (conf/bblayers.conf)
# LAYER_CONF_VERSION is increased each time build/conf/bblayers.conf
# changes incompatibly
LCONF_VERSION = "7"
BBPATH = "${TOPDIR}"
BBFILES ?= ""
BBLAYERS ?= "
/opt/oe/configs/z/build-master/rpi3-64-vc4/layers/meta-raspberrypi
/opt/oe/configs/z/build-master/rpi3-64-vc4/layers/openembedded-core/meta
/opt/oe/configs/z/build-master/rpi3-64-vc4/layers/meta-openembedded/meta-oe
/opt/oe/configs/z/build-master/rpi3-64-vc4/layers/meta-openembedded/meta-gnome
/opt/oe/configs/z/build-master/rpi3-64-vc4/layers/meta-openembedded/meta-python
/opt/oe/configs/z/build-master/rpi3-64-vc4/layers/meta-openembedded/meta-networking
/opt/oe/configs/z/build-master/rpi3-64-vc4/layers/meta-openembedded/meta-multimedia
/opt/oe/configs/z/build-master/rpi3-64-vc4/layers/meta-qt5
/opt/oe/configs/z/build-master/rpi3-64-vc4/layers/meta-qt5-extra
/opt/oe/configs/z/build-master/rpi3-64-vc4/layers/meta-browser
"

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March 10, 2019
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configuration (conf/local.conf -- abridged)
MACHINE ?= "raspberrypi3-64"
DISTRO ?= "nodistro"
DL_DIR ?= "/opt/Downloads"
# gui/gl
MACHINE_FEATURES_append = " vc4graphics"
DISTRO_FEATURES_append = " directfb opengl x11"
PACKAGECONFIG_append_pn-mesa-demos = " glut"
CORE_IMAGE_EXTRA_INSTALL += " glmark2 mesa-demos chromium-x11"
# touchscreen
PACKAGECONFIG_pn-xserver-nodm-init = "nocursor"
WAVESHARE_1024X600_C_2_1 = "1"
# rpi
ENABLE_I2C = "1"
KERNEL_MODULE_AUTOLOAD += "i2c-dev"
ENABLE_SPI_BUS = "1"
ENABLE_UART = "1"
PACKAGE_CLASSES = "package_ipk"
EXTRA_IMAGE_FEATURES ?= "debug-tweaks"

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Case Study

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March 10, 2019
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customers
hardware
manufacturers
RDK

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March 10, 2019
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RDK set-top-box
●
purposefully multi-vendor, multi-architecture
●
but expects a base, functioning system
●
needs to add its own software on top
●
needs to tightly control the base system
●
packages
●
versions
●
functionality (e.g. init system, graphics)

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March 10, 2019
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OpenEmbedded solution
●
RDK is its own distro → RDK (layer)
●
defines packages, behaviour
●
vendors create hardware and provide BSP layers
●
RDK builds images for each device using distro
layer, BSP layer, as well as others
●
RDK generates SDKs for the developers
●
RDK maintains a packagefeed for updates
●
this is not a "home grown" solution, embedded
developers are already familiar with the tools

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Caveats

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●
not all layers work well together
●
OpenEmbedded doesn't catch all mistakes and mis-
matches
●
code is constantly changing, and getting all these
independent projects to work as a cohesive whole
isn't always easy (moving target)
●
layer quality, layer duplications
●
needs a really big build machine
●
works better with a really good connection to the
Internet
●
... and more

SCaLE 17x
March 10, 2019
78 of 78
Thank you!

Using OpenEmbedded

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