Pulsar DTB - device tree blob

Question

I am trying to understand a complication with using a custom device tree blob while using the prebuilt Pulsar image for microZed (http://microzed.org/sites/default/files/design/Pulsar-SoM-Image-Creation_0.zip).

I do not know too much about U-boot, but I have added my own .dtb file in the OVERCBOOT partition and I stop u-boot to add my own commands (build from petalinux tools 2015.2). Taking a look at the getting started guide (http://zedboard.org/sites/default/files/documentations/Wind-River-Getting-Started-with-Pulsar-Linux-OS_2.pdf), i can boot using the commands shown there using the provided blob

> fatload mmc 0 0x3000000 uImage
> fatload mmc 0 0x2A00000 dtb
> setenv bootargs 'console=ttyPS0,115200 root=/dev/mmcblk0p3
rw rootfstype=btrfs softdog.nowayout=0 rootwait'
> bootm 0x3000000 - 0x2a00000

If I change dtb to my own system.dtb, the boot seems to always hang after uncompressing the image.

Ultimately, I would like to add my own seperate .bin file for the PL during u-boot, as well (can do this, and will boot if I use the default dtb file).

I would like to solve this as it seems pretty much the easiest way to get rolling with the Pulsar persistent image. I would like to use my own device tree as I have created my own DMA drivers.

Former Member · Accepted Answer

Hi,

Yup, don't know why just yet, but I've found the same thing when I attempt to boot Pulsar with with a device tree file created from a PetaLinux project, using the same hardware. It simply doesn't work, and hangs as soon as the kernel decompresses.

I'm working with Wind River to resolve this, but at present the workaround is to modify the source provided in the wr-core project (Wind River OpenSourceLabs) and compile that. Or if you haven't installed wr-core on a Linux host, you can decompile the dtb file in the OVERCBOOT partition of the image and modify the resulting DTS and compiling that back into a DTB.

Ron