Re: [yocto] Question regarding custom device tree update
Hi Robert,
Thank you for your reply.
This works and I got my dtb generated in my build directory!
Best wishes,
Sohil
On Wed, Jul 7, 2021 at 10:29 PM Robert Calhoun
wrote:
> > From: yocto@lists.yoctoproject.org on
> behalf of Sohil Shah
> > Sent: Wednesday, June 30, 2021 09:46
> > To: yocto@lists.yoctoproject.org
> > Subject: [yocto] Question regarding custom device tree update
> >
> > (...)
> > I want to build the image using my custom dts file where I enable
> certain peripherals and disable the ones not required. (A test to update
> dtb's in future).
> >
> > I tried different methods found here
> >
> https://stackoverflow.com/questions/38917745/quick-rebuild-of-device-tree-only-with-yocto-bitbake
> >
> > But, I seem to run into some errors when I try to build the image.
> >
> > Please help and let me know if I missed any required information from my
> side.
> >
> >Thank you and Regards,
> > Sohil
>
> Hi Sohil,
>
> First make a custom layer for you modifications and add it to
> bblayers.conf. Then modify your machine definition of KERNEL_DEVICETREE (in
> meta-yourlayer/conf/machine/machinname.conf) to specify multiple device
> trees, e.g.
>
> KERNEL_DEVICETREE = "at91-sama5d27_wlsom1_ek.dtb
> at91-sama5d27_wlsom1_ek_custom.dtb"
>
> Note this should specify the "dtb" (compiled device tree name), not the
> "dts" (source.)
>
> Next, make a .bbappend for your linux recipe that will provide the .dts
> source, something like:
>
> FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
>
> SRC_URI += " \
> file://at91-sama5d27_wlsom1_ek_custom.dts;subdir=git/arch/arm/boot/dts \
> "
>
> Make a subdirectory with package name (e.g. linux-yocto) and put your dts
> in there. The "subdir" directive tells bitbake to drop the dts into the
> appropriate directory for the linux build process to find it. The device
> tree(s) will be built along with linux and put in the image's /boot
> directory. You can select which device tree you want to boot with via
> u-boot, or by manipulating the symbolic links in the /boot directory.
>
> Best wishes,
>
> Rob Calhoun
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Re: [yocto] Question regarding custom device tree update
> From: yocto@lists.yoctoproject.org on behalf
> of Sohil Shah
> Sent: Wednesday, June 30, 2021 09:46
> To: yocto@lists.yoctoproject.org
> Subject: [yocto] Question regarding custom device tree update
>
> (...)
> I want to build the image using my custom dts file where I enable certain
> peripherals and disable the ones not required. (A test to update dtb's in
> future).
>
> I tried different methods found here
> https://stackoverflow.com/questions/38917745/quick-rebuild-of-device-tree-only-with-yocto-bitbake
>
> But, I seem to run into some errors when I try to build the image.
>
> Please help and let me know if I missed any required information from my side.
>
>Thank you and Regards,
> Sohil
Hi Sohil,
First make a custom layer for you modifications and add it to bblayers.conf.
Then modify your machine definition of KERNEL_DEVICETREE (in
meta-yourlayer/conf/machine/machinname.conf) to specify multiple device trees,
e.g.
KERNEL_DEVICETREE = "at91-sama5d27_wlsom1_ek.dtb
at91-sama5d27_wlsom1_ek_custom.dtb"
Note this should specify the "dtb" (compiled device tree name), not the "dts"
(source.)
Next, make a .bbappend for your linux recipe that will provide the .dts source,
something like:
FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
SRC_URI += " \
file://at91-sama5d27_wlsom1_ek_custom.dts;subdir=git/arch/arm/boot/dts \
"
Make a subdirectory with package name (e.g. linux-yocto) and put your dts in
there. The "subdir" directive tells bitbake to drop the dts into the
appropriate directory for the linux build process to find it. The device
tree(s) will be built along with linux and put in the image's /boot directory.
You can select which device tree you want to boot with via u-boot, or by
manipulating the symbolic links in the /boot directory.
Best wishes,
Rob Calhoun
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[yocto] Question regarding custom device tree update
Hello, I am kinda a noob at this so please bear with me. I am using the sama5d27-wlsom1-ek board for my demo and I am trying to make changes to the device tree. So far I have compiled core-image-minimal and find my dtb files are generated in /tmp/work/sama5d27_wlsom1_ek_sd-poky-linux-gnueabi/linux-at91/5.4+gitAUTOINC+3dba8c9991-r0/build/arch/arm/boot/dts folder. Also I find many different dts files in build/tmp/work-shared/sama5d27-wlsom1-ek-sd/kernel-source/arch/arm/boot/dts But where does my machine get device tree files if they are generated inside the build folder and if so where do I place my custom files so that they get called during bitbake. I want to build the image using my custom dts file where I enable certain peripherals and disable the ones not required. (A test to update dtb's in future). I tried different methods found here https://stackoverflow.com/questions/38917745/quick-rebuild-of-device-tree-only-with-yocto-bitbake But, I seem to run into some errors when I try to build the image. Please help and let me know if I missed any required information from my side. Thank you and Regards, Sohil -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#54020): https://lists.yoctoproject.org/g/yocto/message/54020 Mute This Topic: https://lists.yoctoproject.org/mt/83892570/21656 Group Owner: yocto+ow...@lists.yoctoproject.org Unsubscribe: https://lists.yoctoproject.org/g/yocto/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
