Editing Device Tree Dynamically

[Sunim_1]

I want to enable Uart-B

serial@3110000 {
compatible = “nvidia,tegra194-hsuart”;
iommus = <0x06 0x04>;
dma-coherent;
reg = <0x00 0x3110000 0x00 0x10000>;
reg-shift = <0x02>;
interrupts = <0x00 0x71 0x04>;
nvidia,memory-clients = <0x0e>;
dmas = <0x3f 0x09 0x3f 0x09>;
dma-names = “rx\0tx”;
clocks = <0x02 0x9c 0x02 0x66>;
clock-names = “serial\0parent”;
resets = <0x02 0x65>;
reset-names = “serial”;
status = “disabled”;
phandle = <0x2e3>;

I am using Custom Carrier Board with Orin NX Module.
so how do i make changes in the device tree dtb file dynamically . As i don’t want to reflash my orin nx module again and again.

[DaneLLL]

Hi,
Please convert the dtb back to dts, do modification, convert back to dtb and then change FDT in

/boot/extlinux/extlinux.conf

The dtb is applied while booting to kernel stage. Please note it is not applied in bootloader stage and there may be potential issue. It is fine for debugging purpose and we suggest do clean re-flash for formal system image.

[Sunim_1]

So here in FDT, do i need to replace the name of dtb file where i make changes ?

TIMEOUT 30
DEFAULT primary

MENU TITLE L4T boot options

LABEL primary
MENU LABEL primary kernel
LINUX /boot/Image
FDT /boot/dtb/kernel_tegra234-p3767-0000-p3768-0000-a0.dtb
INITRD /boot/initrd
APPEND ${cbootargs}

When testing a custom kernel, it is recommended that you create a backup of

the original kernel and add a new entry to this file so that the device can

fallback to the original kernel. To do this:

1, Make a backup of the original kernel

sudo cp /boot/Image /boot/Image.backup

2, Copy your custom kernel into /boot/Image

3, Uncomment below menu setting lines for the original kernel

4, Reboot

LABEL backup

MENU LABEL backup kernel

LINUX /boot/Image.backup

FDT /boot/dtb/kernel_tegra234-p3767-0000-p3768-0000-a0.dtb

INITRD /boot/initrd

APPEND ${cbootargs}