Change name of device tree

[chris.brown2]

Hi,

I’m attempting to use a customised device tree on the jetson nano.

I have created the relevant device tree and it is built in the kernel. The device tree is deployed in the /boot partition and I have changed the /boot/extlinux/extlinux.conf file to be:

default Yocto
label Yocto
   kernel /Image
   fdtdir /
   fdt /boot/mydevicetree.dtb
append root=PARTUUID=3eeb3f1f-02 rootwait

When booting the nano still retains the original device tree. What am I doing wrong?

The boot states:

[ 0.452830] DTS File Name: /dvs/git/dirty/git-master_linux/kernel/kernel-4.9/arch/arm64/boot/dts/../../../../../../hardware/nvidia/platform/t210/porg/kernel-dts/tegra210-p3448-0000-p3449-0000-a02.dts

I also can see it’s not my tree in /proc:

cat /proc/device-tree/nvidia,dtsfilename
/dvs/git/dirty/git-master_linux/kernel/kernel-4.9/arch/arm64/boot/dts/../../../../../../hardware/nvidia/platform/t210/porg/kernel-dts/tegra210-p3448-0000-p3449-0000-a02.dts

From u-boot I get:

Found /boot/extlinux/extlinux.conf
Retrieving file: /boot/extlinux/extlinux.conf
216 bytes read in 20 ms (9.8 KiB/s)
1:      OE4Tegra Demonstration Distro
Retrieving file: /boot/extlinux/../initrd
2094831 bytes read in 114 ms (17.5 MiB/s)
Retrieving file: /boot/extlinux/../Image
37640200 bytes read in 1626 ms (22.1 MiB/s)
append: tegraid=21.1.2.0.0 ddr_die=4096M@2048M section=512M memtype=0 vpr_resize usb_port_owner_info=0 lane_owner_info=0 emc_max_dvfs=0 touch_id=0@63 video=tegrafb no_console_suspend=1 console=ttyS0,115 
## Flattened Device Tree blob at 83100000
   Booting using the fdt blob at 0x83100000
ERROR: reserving fdt memory region failed (addr=0 size=0)
ERROR: reserving fdt memory region failed (addr=0 size=0)
   Using Device Tree in place at 0000000083100000, end 000000008317e68d

[DaveYYY]

Hi, as stated in the FAQ, we’d suggest you do a whole re-flash to make sure the change takes effect.

[chris.brown2]

Yes, I’ve tried turning it off and on again as well. Lol.

[DaveYYY]

Hi, have you tried to use codes directly released by NVIDIA, not the Yocto-based one?

[chris.brown2]

No, our solution requires a Yocto implementation. I have managed to get the image working by using the output from the tegraflash class. I didn’t realise that the output of the sdcard image vs the tegraflash image were so radically different. I need to investigate the tegraflash class tio understand it fully. In our implementation we will need to read hardware from u-boot and select a device tree based on specific hardware. This will need multiple device tree configurations. Is there a best practice way of doing this? Does the image contain the device tree as I don’t see an ‘fdt load’ for example in u-boot output when booting the kernel.

[WayneWWW]

I would suggest you can share the full log and which version of jetpack your BSP is based on first.

Your partial log is hard to tell which part has problem.