[meta-freescale] dts and dtb files

[Mats Kärrman]

Hi Niclas,

(Please keep the list on cc)

At Friday, January 17, 2014 11:12 PM, Niklas Molin [niklas.p.molin at gmail.com] wrote:
> So in my .conf file (machine config) I have the KERNEL_DEVICETREE, which points to some .dtb files.
> Will these .dtb files be generated by "compiling" the dts/dtsi files?
> If so, where do setup the path to where these dts/dtsi files are located.
> Right now when I look in my Sabresd directory I have dts/dtsi files in following paths:
> cortexa9hf-vfp-neon-poky-linux-gnueabi/linux-libc-headers/3.10-r0/linux-3.10/arch/arm/boot/dts/linux-imx/3.10.9-r0/image/usr/src/kernel/arch/arm/boot/dts/
> cortexa9hf-vfp-neon-poky-linux-gnueabi/linux-libc-headers/3.10-r0/linux-3.10/arch/arm/boot/dts/linux-imx/3.10.9-r0/package/usr/src/kernel/arch/arm/boot/dts/
> cortexa9hf-vfp-neon-poky-linux-gnueabi/linux-libc-headers/3.10-r0/linux-3.10/arch/arm/boot/dts/linux-imx/3.10.9-r0/packages-split/kernel-dev/usr/src/kernel/arch/arm/boot/dts/
> cortexa9hf-vfp-neon-poky-linux-gnueabi/linux-libc-headers/3.10-r0/linux-3.10/arch/arm/boot/dts/linux-imx/3.10.9-r0/git/arch/arm/boot/dts/
> cortexa9hf-vfp-neon-poky-linux-gnueabi/linux-libc-headers/3.10-r0/linux-3.10/arch/arm/boot/dts/linux-imx/3.10.9-r0/sysroot-destdir/usr/src/kernel/arch/arm/boot/dts/
> cortexa9hf-vfp-neon-poky-linux-gnueabi/linux-libc-headers/3.10-r0/linux-3.10/arch/arm/boot/dts/
> From which directory is it "compiling" the dts/dtsi files?

The .dtb is built as part of the Linux kernel build, not the
linux-libc-headers. On my machine I find the .dts source files at:
./build/tmp/work/${MACHINE}-poky-linux-gnueabi/linux-imx/3.10.9-r0/git/arch/arm/boot/dts

You need to make a patch for the linux kernel source or otherwise
copy your .dts file to this directory before do_install.
The .dtb files listed in your machine conf are compiled from .dts
files with the same name. The compiler is called "dtc" and is a
tool built as part of the linux kernel build (see .../git/scripts/dtc).
You can run the tool with "--help" for more info. A good feature
is that you can run it backwards, producing a .dts from your .dtb
so you can make sure you've got all your changes right.

BR // Mats