Device-tree/model file changes

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1

Hi all,

I’m trying to edit the /proc/device-tree/model file in the debian-10.3-iot-armhf-2020-04-06 version file system. I have tried as root and changed the permissions of the file and its parent directories but the file remains unwritable. Can anyone tell me how I am supposed to edit this file?

2

You don't... It doesn't exist as a file, just a virtual name in the
file system. When you read it, the OS generates the data it gives to you.
https://tldp.org/LDP/Linux-Filesystem-Hierarchy/html/proc.html

  I suspect you need to edit the appropriate device tree source file,
compile it into a DTB, and install that DTB where ever u-boot is looking...

debian@beaglebone:~$ cat /proc/device-tree/model
TI AM335x BeagleBone Blackdebian@beaglebone:~$
debian@beaglebone:~$ grep -i "TI AM335x BeagleBone Black"
/opt/source/dtb-4.19-ti/src/arm/*.dts
/opt/source/dtb-4.19-ti/src/arm/am335x-boneblack-audio.dts: model = "TI
AM335x BeagleBone Black";
/opt/source/dtb-4.19-ti/src/arm/am335x-boneblack-bbb-exp-c.dts: model = "TI
AM335x BeagleBone Black";
/opt/source/dtb-4.19-ti/src/arm/am335x-boneblack-bbb-exp-r.dts: model = "TI
AM335x BeagleBone Black";
/opt/source/dtb-4.19-ti/src/arm/am335x-boneblack-bbbmini.dts: model = "TI
AM335x BeagleBone Black";
/opt/source/dtb-4.19-ti/src/arm/am335x-boneblack.dts: model = "TI AM335x
BeagleBone Black";
/opt/source/dtb-4.19-ti/src/arm/am335x-boneblack-roboticscape.dts: model =
"TI AM335x BeagleBone Black RoboticsCape";
/opt/source/dtb-4.19-ti/src/arm/am335x-boneblack-uboot.dts: model = "TI
AM335x BeagleBone Black";
/opt/source/dtb-4.19-ti/src/arm/am335x-boneblack-uboot-univ.dts: model =
"TI AM335x BeagleBone Black";
/opt/source/dtb-4.19-ti/src/arm/am335x-boneblack-wireless.dts: model = "TI
AM335x BeagleBone Black Wireless";
/opt/source/dtb-4.19-ti/src/arm/am335x-boneblack-wireless-roboticscape.dts:
model = "TI AM335x BeagleBone Black Wireless RoboticsCape";
/opt/source/dtb-4.19-ti/src/arm/am335x-boneblack-wl1835mod.dts: model = "TI
AM335x BeagleBone Black";
debian@beaglebone:~$

3

Ok, so what I think I need to do is make a custom DTB for my board. To build one do I just create a DTS file in the /opt/source/dtb-5.4-ti/src and run make /src//custom.dts? Also to install the DTB for u-boot, I need to move the file into /boot/dtbs/$(uname -r) for debian as stated here https://elinux.org/Beagleboard:U-boot_partitioning_layout_2.0#u-boot_dtb_search_order right?

4

You are now beyond what I can find by Google and on-board file
searches.

5

Ok, thanks for your help.