TipsAndTricks/BuildingZephyrImages

2022-09-25T10:51:19Z

RzR:

Back to [[TipsAndTricks]]
== Introduction ==
Yocto offers an alternative way of building [https://www.zephyrproject.org/ Zephyr Project] images by using the [http://git.yoctoproject.org/cgit/cgit.cgi/meta-zephyr meta-zephyr] layer.

== Configuration ==
You'll need to install the following additional package <tt>python3-pexpect</tt>. If you're going to using the Arduino 101 board, you'll also need to configure <tt>dfu-util</tt> as follows:

=== Using DFU ===
Device Firmware Update (DFU) allows you to flash A101 images over USB without the need for a JTAG adaptor. First you'll need to install the package <tt>dfu-util</tt> on your Linux distro. By default dfu-util needs root privileges to run. You work around this with the following udev rules
* If on Fedora, you need to create the system group plugdev
$ sudo groupadd -r plugdev
* Add user to plugdev group
$ sudo usermod -a -G plugdev $USER
* Create file <tt>etc/udev/rules.d/50-arduino101.rules</tt> and add the following linr
SUBSYSTEMS=="usb", ATTRS{idVendor}=="8087", ATTRS{idProduct}=="0aba", GROUP="plugdev", MODE="0666"
* Reload udev rules
$ sudo udevadm control --reload-rules

=== Zephyr Layer ===
meta-zephyr layer can be found at git://git.yoctoproject.org/meta-zephyr. The layer supports dunfell and master branches and is dependent on the equivalent poky branch.

== Boards and Machines ==
Zephyr BOARDS typically map to bitbake MACHINES, but underscores become dashes. e.g. BOARD=arduino_101_sss maps to MACHINE = "arduino-101-sss"

== Building Zephyr samples ==
The following instructions build the philosophers sample.
=== Recipe ===
The recipe is pretty simple, see below.
* Think of the require statements as the zephyr base class (could/should be <tt>inhert zephyr-in-tree-build</tt> instead ?
* <tt>inhert deploy</tt> adds a deploy task (it's a standard poky base class)
* ZEPHYR_SRC_DIR sets location of application
* do_deploy puts image in a known location

<pre>
require zephyr-kernel.inc
require zephyr-kernel-common.inc
inherit deploy

ZEPHYR_SRC_DIR = "${S}/samples/philosophers"
ZEPHYR_BASE = "${S}"
OECMAKE_SOURCEPATH = "${ZEPHYR_SRC_DIR}"

do_deploy () {
install -D ${B}/zephyr/${ZEPHYR_MAKE_OUTPUT} ${DEPLOYDIR}/${PN}.elf
}

addtask deploy after do_compile
do_install[noexec] = "1"
</pre>

=== Targeting QEMU ===
Here are the steps. We'll use the kirkstone (LTS) branch for stability.
<pre>
export MACHINE=qemu-x86
export DISTRO="zephyr"
branch=kirkstone

git clone -b ${branch} --recursive --depth 1 git://git.yoctoproject.org/meta-zephyr/
git clone -b ${branch} --recursive --depth 1 git://git.yoctoproject.org/poky
git clone -b ${branch} --recursive --depth 1 git://git.openembedded.org/meta-openembedded
source poky/oe-init-build-env
bitbake-layers add-layer ../meta-openembedded/meta-oe
bitbake-layers add-layer ../meta-openembedded/meta-python
bitbake-layers add-layer ../meta-zephyr/meta-zephyr-core
bitbake-layers add-layer ../meta-zephyr/meta-zephyr-bsp

</pre>

Now build a Qemu image of the canonical Zephyr sample

bitbake zephyr-philosophers
Running zephyr qemu image
runqemu qemu-x86
And will produce output like this
:[[File:Zehpyr-philosophers-screen-shot.png]]

=== Arduino 101 ===
Let's build the philosophers sample for Arduino 101 x86 core. Set up as for [[TipsAndTricks/BuildingZephyrImages#QEMU|QEMU]] but set machine as follows
MACHINE = "arduino-101"
Then run
bitbake zephyr-philosophers
Note that there will be significant rebuild, as although both qemu-x86 and arduino-101 are 386 class devices, arduino-101 uses the subtly different IAMCU toolchain.

After build complete, use the flash_usb task to flash the target via DFU
bitbake zephyr-philosophers -c flash_usb
Sample text output will appear on serial port.

== Arduino 101 and Multiconfig ==
Inter Processor Mailbox (IPM) is a Zephyr driver that allows communications between processors. The IPM sample shows communication between the x86 and ARC cores and is good way to exercise multi-config.
=== Configuration ===
Add the following to <tt>local.conf</tt>
DISTRO = "zephyr"
MACHINE ?= "arduino-101"
BBMULTICONFIG ?= "arduino-101 arduino-101-sss"
Create folder <tt>multiconfig</tt> under <tt>conf</tt> with a file <tt>arduino-101-sss.conf</tt>
+ conf
+ multiconfig
arduino-101.conf
arduino-101-sss.conf
The file <tt>conf/multiconfig/arduino-101.conf</tt> should contain:
MACHINE="arduino-101"
TMPDIR="${TOPDIR}/tmp-arduino-101"
The file <tt>conf/multiconfig/arduino-101-sss.conf</tt> should contain:
MACHINE="arduino-101-sss"
TMPDIR="${TOPDIR}/tmp-arduino-101-sss"
The TMPDIR settings are a workaround a multiconfig bug exposed by the meta-zephyr.

=== Building ===
Build both images:
$ bitbake multiconfig:arduino-101:zephyr-ipm multiconfig:arduino-101-sss:zephyr-ipm

=== Flashing ===
Once the build is finished (both images are built), flash:
$ bitbake multiconfig:*:zephyr-ipm -cflash_usb

=== Running ===
Press reset, serial output should look like this
<pre>
===== app started ========
Hello from application processor (x86)! (0) Sensor Subsystem (ARC) is sleeping, mailbox status: 00000000 mask fffff0ef
sending messages for IPM device 0xa80064e4
sending messages for IPM device 0xa80064d8
sending messages for IPM device 0xa80064cc
Hello from application processor (x86)! (1) Sensor Subsystem (ARC) is sleeping, mailbox status: 00000000 mask fffff0ef
pinging sensor subsystem (ARC) for counter status
ipm_console0: 'counters: 148 6 7'
ipm_console0: 'Hello from ARC!'
Hello from application processor (x86)! (2) Sensor Subsystem (ARC) is sleeping, mailbox status: 00000000 mask fffff0ef
pinging sensor subsystem (ARC) for counter status
ipm_console0: 'counters: 69 50 35'
</pre>

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TipsAndTricks/BuildingZephyrImages