Linux/AM3358: Pinmux DTSI to Processor SDK workflow?

Thanks Pavel,

I agree this page is the 'holy grail' for kernels and DTBs, but unless I'm going mad,  none of the make examples work on the latest SDK (05.03.00.07). Having checked the Makefile, all the targets have changed and it doesn't seem to allow me to build individual dtbs anymore.  Can you confirm this at your end (to prove I'm not going mad)?

Mat

Mathew,

I tried to build DTB file for AM335x TI EVM and the process is successful. I have some warnings, but the result is am335x-evm.dtb file.

I follow the instructions and execute below commands:

host:{PSDK}/board-support/linux-4.14.79+gitAUTOINC+e669d52447-ge669d52447$ export PATH={PSDK}/linux-devkit/sysroots/x86_64-arago-linux/usr/bin:$PATH
host:{PSDK}/board-support/linux-4.14.79+gitAUTOINC+e669d52447-ge669d52447$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- distclean
host:{PSDK}/board-support/linux-4.14.79+gitAUTOINC+e669d52447-ge669d52447$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- tisdk_am335x-evm_defconfig
host:{PSDK}/board-support/linux-4.14.79+gitAUTOINC+e669d52447-ge669d52447$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- zImage
host:{PSDK}/board-support/linux-4.14.79+gitAUTOINC+e669d52447-ge669d52447$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- am335x-evm.dtb

I have below messages when building DTS fille:

CHK scripts/mod/devicetable-offsets.h
DTC arch/arm/boot/dts/am335x-evm.dtb
arch/arm/boot/dts/am335x-evm.dtb: Warning (phys_property): Missing property '#phy-cells' in node /ocp/usb@47400000/usb-phy@47401300 or bad phandle (referred from /ocp/usb@47400000/usb@47401000:phys[0])
arch/arm/boot/dts/am335x-evm.dtb: Warning (phys_property): Missing property '#phy-cells' in node /ocp/usb@47400000/usb-phy@47401b00 or bad phandle (referred from /ocp/usb@47400000/usb@47401800:phys[0])

As a result I have the DTB file in below folder:

{PSDK}/board-support/linux-4.14.79+gitAUTOINC+e669d52447-ge669d52447/arch/arm/boot/dts/am335x-evm.dtb


Another approach you can try is to build DTS file through the top-level makefile:

{PSDK}/Makefile

See below user guide:

software-dl.ti.com/.../Overview_Getting_Started_Guide.html

Regards,
Pavel

Thanks Pavel, I see where I was going wrong:

I was calling make from the top-level SDK directory, not board-supprt/linux[...]

As a result, I can now build my .dtb file.

Onto the next stage of the workflow, however...

After building the .dtb I'm trying to install it on my target image. To do this, I've created the dtb, loaded it into the rootfs/boot directory, then inserted a uEnv.txt entry:

fdtfile=<my device tree file.dtb>

This has led to two further questions.
1. Is this correct, or would it be subject to the non-uEnv.txt entries overriding it later in the boot? (I ask because it doesn't currently work: but haven't fully investigated yet)

2. Is there any easy way to build/install the dtb file using the Yocto build (meta-custom layer)? This would have a better chance of integration vs my current method of building the FS using Yocto, jumping over to SDK for the DTB, installing on target device, then manually copying over the uEnv and DTB files.

Mathew,

Refer to the below user guides and pointers:

software-dl.ti.com/.../Foundational_Components_Kernel_Users_Guide.html

Installing the Kernel Image and Device Tree Binaries

software-dl.ti.com/.../How_to_Guides_Target.html
processors.wiki.ti.com/.../How_to_Change_dtb_File

e2e.ti.com/.../558802

Regards,
Pavel