How to do the pinmux change and compile the device tree source(.dts) to .dtb

Hi Shu,

You need to download and install the full SDK from http://software-dl.ti.com/sitara_linux/esd/AM335xSDK/latest/index_FDS.html

Thanks for you reply. I am really new to Linux. I downloaded the SDK.

Can you please let me know in the SDK where to get the device tree source? and how to recompile it and the kernel after make the pinmux changes?  Can I use the current pre-built image since it works fine for us and we just need the pinmux change?

Thanks again. 

Shu

Hi Biser,

I found the .dts files in the /arch/arm/boot/dts of the SDK. Can you please let me know how to recompile it and recompile the kernel?

Can I still use the current pre-built TI image? Can I just replace the current am335x-boneblack.dtb and zImage with the recompiled the my.dtb and recompiled zImage ?

Regards,

Shu

Sorry, I'm not a Linux expert, but you can go to the wiki portal http://processors.wiki.ti.com/index.php/Sitara_AM335x_Portal and from there you will find a lot of wiki pages on Linux.

Hi Shu,

Yes, you can use a pre build zImage and .dtb files.

BR
Ivan

Ivan,

Thanks for your reply. Can you please let me know how to recompile the device tree source file and the Linux kernel? Then I can replace the old .dtb file and the old zImage.

Biser,

Thanks for your link.

Regards,

Shu 

Your steps from your first post should work if you are using a 3.x kernel.  If you are cross-compiling
(building a Linux ARM image on an x86 machine), you will need to add some variables to make.
In particular, check that your CROSS_COMPILE variable is set correctly.
For my specific environment (Beaglebone Black), my commands might look like this:

make ARCH=arm CROSS_COMPILE=armv7a-hardfloat-linux-gnueabihf- omap2plus_defconfig
this will create a .config file in the kernel directory which the kernel uses to build.
you should only need to do this once.  if you change any options in the .config this will overwrite them

make ARCH=arm CROSS_COMPILE=armv7a-hardfloat-linux-gnueabihf- menuconfig
if you need to change any options before building the kernel

make ARCH=arm CROSS_COMPILE=armv7a-hardfloat-linux-gnueabihf-
compile the kernel

make ARCH=arm CROSS_COMPILE=armv7a-hardfloat-linux-gnueabihf- zImage dtbs 
create a zImage and compile all the dtb files

make ARCH=arm CROSS_COMPILE=armv7a-hardfloat-linux-gnueabihf- modules
compile any modules built for the kernel

make ARCH=arm CROSS_COMPILE=armv7a-hardfloat-linux-gnueabihf-
modules_install INSTALL_MOD_PATH=<rootfs location>
install the recompiled modules to the destination drive

Now just copy the zImage, .dtb file to the destination and you should be good to go. 
To find out where they go, just find the zImage and dtb file on the destination drive
and replace them (locations can vary).

Hi,

I follow the link that you provided. http://processors.wiki.ti.com/index.php/Linux_Kernel_Users_Guide

When compiling kernel, I typed " make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- zImage. It took about 5 mins and I got the error below. Should I use a different compiler or what? I do not have the compiler that James had.

"make ARCH=arm CROSS_COMPILE=armv7a-hardfloat-linux-gnueabihf-"

I only made one change to the am335x-bone-common.dtsi file. 

  CC      lib/show_mem.o
  CC      lib/string.o
  CC      lib/timerqueue.o
  CC      lib/vsprintf.o
  AR      lib/lib.a
  LINK    vmlinux
  LD      vmlinux.o
  MODPOST vmlinux.o
  GEN     .version
  CHK     include/generated/compile.h
  UPD     include/generated/compile.h
  CC      init/version.o
  LD      init/built-in.o
drivers/built-in.o: In function `omap2_mbox_remove':
/home/vdev/ti-sdk-am335x-evm-07.00.00.00/board-support/linux-3.12.10-ti2013.12.01/drivers/mailbox/mailbox-omap2.c:536: undefined reference to `omap_mbox_unregister'
drivers/built-in.o: In function `omap2_mbox_probe':
/home/vdev/ti-sdk-am335x-evm-07.00.00.00/board-support/linux-3.12.10-ti2013.12.01/drivers/mailbox/mailbox-omap2.c:501: undefined reference to `omap_mbox_register'
make: *** [vmlinux] Error 1

Regards,

Shu

I resolved it by cleaning the kernel sources. 

make ARCH=arm CROSS_COMPILE=<compiler> distclean

Thanks.