[yocto] Where to find help for yocto application and and system development

Fri Jan 27 10:16:55 PST 2017

I hear you asking a lot of reasonable questions that probably seem trivial
to most of us who have been using Yocto for a while.  We tend to forget
what it was like the first time.

I can't tell what reading and research you've done so far.  Have you read
both the BitBake User Manual
<http://www.yoctoproject.org/docs/2.2/bitbake-user-manual/bitbake-user-manual.html>
 and Yocto Project Reference Manual
<http://www.yoctoproject.org/docs/2.2/ref-manual/ref-manual.html>.  Those
explain many vital details such as: what many of the variables, like
SRC_URI, are used for, the syntax rules for recipes, directory structure of
the metadata, and more.  It's a lot to read and some sections are confusing
but it's a huge resource that will answer many questions.

As others have mentioned, IRC and this mailing list are both excellent
places to ask questions.  I personally get asked a lot of questions that
require some research and more lengthy explanations.  I've started writing
my responses in an advice column form on my blog at
http://www.kc8apf.net/category/dear-brother-yocto/.  (Note to Yocto
experts: I'm certain to get things wrong in my explanations.  Please send
in corrections as well.  I'm happy to include them.).

Rick

On Fri, Jan 27, 2017 at 6:51 AM, Jakob Hasse <
jakob.hasse at smart-home-technology.ch> wrote:

> Hello Leon,
>
> Thank you for the answer!
>
> I read the documentation, it doesn't really give me more than general
> hints what to try (or maybe I read at the wrong place). I also read in
> "Embedded Linux Project Using Yocto Project Cookbook". I know that bitbake
> should use autotools somehow. I set up my directories exactly like the
> other projects which work without any issues. The other project, however,
> are simple executables.
>
> What is unclear to me:
> To what shall SCR_URI point? The git repo? Downloaded .tar.gz file? The
> source dir copied into the project directory besided the recipe)? I tried
> all these ways already, each bringing up a different error, basically.
>
> Do I need to change do_install() or does the makefile handles it? If I
> interpret the documentation and the book correctly, I don't need to do
> anything more in the recipe...
>
> When I want to fetch from git, it complains about the SRCREF not being
> set. So I tried to set it to the most recent commit of the repo in the
> recipe file, but it gave another error. I also tried to "append" it somehow
> to the git URI which didn't work either.
>
>
> Note that I need to include the development version of openssl, not
> openssl itself (on Ubuntu host you do something like apt install
> openssl-dev).
>
> The recipe is appended, if it helps:
>
> # Recipe created by recipetool
> # This is the basis of a recipe and may need further editing in order to
> be fully functional.
> # (Feel free to remove these comments when editing.)
> #
> # WARNING: the following LICENSE and LIC_FILES_CHKSUM values are best
> guesses - it is
> # your responsibility to verify that the values are complete and correct.
> LICENSE = "Unknown"
> LIC_FILES_CHKSUM = "file://COPYING;md5=c8ee358fdf91d887aa014c8712e8c22d"
> SRC_URI[md5sum] = "da7315f9bc22ff4c24a1cef404b4f3a8"
> # No information for SRC_URI yet (only an external source tree was
> specified)
> SRC_URI = "/usr/local/dey-2.0/sources/meta-training/recipes-
> examples/tr-50/tr-50-0.1/"
> #SRC_URI = "git://https://github.com/inhedron/libtr50.git;rev=
> aedc45c4e9a9a9a3aa301616ad03f07b903d9a81"
> #SRC_URI = "file:///home/jakob/Downloads/libtr50-0.1.0.tar.gz"
> #SRCREF = "aedc45c4e9a9a9a3aa301616ad03f07b903d9a81"
>
> DEPENDS = "openssl "
> # NOTE: if this software is not capable of being built in a separate build
> directory
> # from the source, you should replace autotools with autotools-brokensep
> in the
> # inherit line
> inherit autotools
>
> # Specify any options you want to pass to the configure script using
> EXTRA_OECONF:
> EXTRA_OECONF = " --with-examples"
>
> #do_install(){
> #    eo_runmake install DESTDIR=${D} PREFIX=${D}
> #}
>
> Thanks in advance for any answers!
>
> All the best,
> Jakob
>
>
> On 27.01.2017 14:39, Leon Woestenberg wrote:
>
> Hi Jakob,
>
> welcome on-board.
>
> The Yocto community expects you to re-use the available documentation and
> online resources (or even offline resources like books) on Yocto or
> OpenEmbedded. Then if things remains unclear you can ask questions here on
> the mailing list and on IRC channels yocto.
>
> Your question (and probably a lot of subsequent things you learn on the
> way) can be answered by the documentation and existing resources.
>
> I would recommend to read the documentation, then find an existing recipe
> that uses "autotools" and another that DEPENDS on openssl.
>
> There are a lot of resources online:
>
> http://www.yoctoproject.org/docs/1.6.1/dev-manual/dev-
> manual.html#new-recipe-writing-a-new-recipe
>
> https://www.yoctoproject.org/tools-resources/community/irc
>
> Regards,
>
> Leon.
>
> On Fri, Jan 27, 2017 at 12:43 PM, Jakob Hasse <jakob.hasse at smart-home-
> technology.ch> wrote:
>
>> Hello,
>>
>> I'm beginning with Yocto.
>> I would like to know where to find general help (like a forum, or mailing
>> lists) for my Yocto-related technical problems.
>> Right now I have problems just integrating a library into my build. Later
>> I will also do system development.
>>
>> If this helps, a further description of my most urgent problem:
>>
>> I want to integrate the tr-50 library, available on github:
>>
>> https://github.com/inhedron/libtr50
>>
>> It is managed via autotools.
>> I built a new project subdirectory in my custom layer for the lib.
>> I built a basic recipe (with some tool) which, in principle should
>> somehow recognize the autotools and build the project then. I changed the
>> SCR_URI to the local .tar.gz file. But when I build, it comes down to this:
>> make: *** No rule to make target 'install'.  Stop.
>> I don't know if and which parameters I should change in the recipe.
>> Another problem is that the lib needs openssl-dev. I can't find how to
>> include openssl-dev into the Yocto build.
>>
>> Looking forward for your answers, best regards,
>> Jakob
>>
>> --
>> Jakob Hasse
>> Software Developement
>>
>> E: jakob.hasse at smart-home-technology.ch
>> T: +41 44 552 02 66
>>
>> Smart Home Technology GmbH
>> www.smart-home-technology.ch
>>
>> --
>> _______________________________________________
>> yocto mailing list
>> yocto at yoctoproject.org
>> https://lists.yoctoproject.org/listinfo/yocto
>>
>
>
> --
> Jakob Hasse
> Software Developement
>
> E: jakob.hasse at smart-home-technology.ch
> T: +41 44 552 02 66 <+41%2044%20552%2002%2066>
>
> Smart Home Technology GmbHwww.smart-home-technology.ch
>
>
> --
> _______________________________________________
> yocto mailing list
> yocto at yoctoproject.org
> https://lists.yoctoproject.org/listinfo/yocto
>
>
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