Add custom device tree to image in IMX8MPLUS using devtool

[vignesh_r]

Hi Team,
I try to integrate MAX98357A with IMX8MPEVK.
I have own custom dts.
1.created own meta layer.
2.devtool modify linux-imx and workspace is created.
3.Copied dts file to build/workspace/sources/linux-imx/arch/arm64/boot/dts/freescale/imx8mp-evk-max98357a.dts
4.dtb-$(CONFIG_ARCH_MXC) += imx8mp-evk-max98357a.dtb is added in build/workspace/sources/linux-imx/arch/arm64/boot/dts/freescale/Makefile.
5.Created patch by devtool update-recipe linux-imx -a imx-yocto-bsp/sources/meta-test .
0001-dts-added-for-max98357a.patch to imx-yocto-bsp/sources/meta-test/recipes-kernel/linux/linux-imx/0001-dts-added-for-max98357a.patch
6.Build kernel - bitbake linux-imx

I could not see my dtb in build/tmp/work/imx8mp_lpddr4_evk-poky-linux/linux-imx/6.1.36+git999-r0/linux-imx-6.1.36+git999/arch/arm64/boot/dts/freescale and also in my image.

[vignesh_r]

Hi,
Any help here?

[joanxie]

I've already mailed to you, pls check it

[vignesh_r]

Hi,

how to create a cutomized camera on yocto - NXP Community 
How to use Devshell to compile device tree files. - NXP Community

Thanks for the links, I can refer. I am trying build dts where I am facing syntax errors.
Once it is resolved, I will check that dtb in image.
Kindly close this thread.

[joanxie]

good to hear this, I will close it

[vignesh_r]

Hi Joanxie,

I have copied dts to build/tmp/work-shared/imx8mp-lpddr4-evk/kernel-source/arch/arm64/boot/dts/freescale/imx8mp-evk-max98357a.dts.
then bitbake -c devshell virtual/kernel & make dtbs. Now it is build successfully.
I can see dtb in /build/tmp/work/imx8mp_lpddr4_evk-poky-linux/linux-imx/6.1.36+gitAUTOINC+04b05c5527-r0/build/arch/arm64/boot/dts/freescale.
Then I exit from devshell.
bitbake -c compile virtual/kernel
bitbake -c deploy virtual/kernel
bitbake linux-imx
bitbake myreceipe
bitbake myimage

I could not find my dtb in imx-yocto-bsp/build/tmp/deploy/images/imx8mp-lpddr4-evk folder.
I copied wic image & flashed in sd card, just connected to pc & checked boot folder there also dtb is not available.
Anyway try to boot with fdtfile variable in uboot,dtb is not available.
So Build image that doesnt have dtb. Is dtb should be added in machine config or some place? Can you please help here?

[joanxie]

I haven't imx8mp board right now, if I remember it correctly, for  the bsp 6.1.36, you can find dtb file and image under /run/media/bootxxxx folder, you also can check this detailed path from your boot up logfile, then you just put your new dtb file there, then reboot the board, use the "setenv fdtfile <your own dtb>" to set your own dtb file, you don't need build the new image and flash to the board again, which too waste time

[vignesh_r]

Hi,

Thanks for the input.
 It is core-image minimal. So how can we place the dtb file in run/media/bootxxxx folder?
Could you please share any reference thread or steps to place the dtb file directly into that path.
Are you referring that copy file from pc to sd card path when it is connected to pc?

[vignesh_r]

Hi,

I have copied dtb from pc to SDCARD . i.e in boot folder.
I have set fdtfile as my dtb.
Then exectued run loadfdt. So it is properly loaded.
But unfortunately, after booting kernel, panic is happened. Let me check and come back.

[joanxie]

if you already put your own dtb in the sd card, when you reboot board, you can use "setenv fdtfile xxx" xxx is your new dtb file, use "saveenv" to save it, then use bootcmd to boot the board again