Re: [yocto] How to define and build device tree in Yocto?

2019-05-07 Thread Bas Mevissen
On 2019-05-07 08:41, Gabriele Zampieri wrote: Hi all, Bas' defconfig trick (do_set_custom_defconfig) is already implemented by Yocto itself: just add a file called defconfig to SRC_URI and the system will apply it for you (you can read kernel_do_configure in kernel.bbclass) . For more

Re: [yocto] How to define and build device tree in Yocto?

2019-05-07 Thread Gabriele Zampieri
Hi all, Bas' defconfig trick (do_set_custom_defconfig) is already implemented by Yocto itself: just add a file called defconfig to SRC_URI and the system will apply it for you (you can read kernel_do_configure in kernel.bbclass) . For more information check

Re: [yocto] How to define and build device tree in Yocto?

2019-05-06 Thread JH
Hi Bas and Gabriele, Thank you so much for you advice. > My usual way of doing it is as follows: > > I usually don't need to make large modifications to the kernel source, > so I don't need to clone the kernel, but use the default kernel for the > SoC with some patches. So do I. > I use a

Re: [yocto] How to define and build device tree in Yocto?

2019-05-06 Thread Bas Mevissen
On 5/5/19 2:03 PM, JH wrote: Hi, Hi JH, I think the device tree blob is build from device tree source, but I could not find any dts files in recipe source directory, there are many dts files in build directory and there are dtb in build directory. Already answered by Gabriele. If I

Re: [yocto] How to define and build device tree in Yocto?

2019-05-06 Thread Gabriele Zampieri
Hi, > but there is no imx6ull-14x14-evk.dts it is located in arch/arm/boot/dts/imx6ull-14x14-evk.dts and it is compiled (among others dts) while building virtual/kernel task. Setting KERNEL_DEVICETREE = "imx6ull-14x14-evk.dtb" simply tells to bitbake to put a copy of imx6ull-14x14-evk.dtb

Re: [yocto] How to define and build device tree in Yocto?

2019-05-06 Thread JH
Thanks Gabriele, Yes, I have already added KERNEL_DEVICETREE = "imx6ull-14x14-evk.dtb" to generate an image running on imx6 EVK. What I don't understand is how that imx6ull-14x14-evk.dtb was compiled? I thought all dtb are compiled from dts files, but there is no imx6ull-14x14-evk.dts, the

Re: [yocto] How to define and build device tree in Yocto?

2019-05-06 Thread Gabriele Zampieri
Hi, The easiest way is to add them via patches. You can write a recipe that patch the Linux tree and put it in your meta layer (usually in meta-xxx/recipes-kernel/linux). Then you need to tell Yocto to export the dtb via KERNEL_DEVICETREE variable (