Device tree load in 4.1 when migrating from 3.8.x

Matt3 · May 9, 2016, 6:12pm

Hi,

In the process of migrating from 3.8.x to 4.1.21 and trying to get my device tree to load manually (eventually to load on boot).

As I understand it device trees are supported in 4.1.x – yes?

I the the .dts compiles with out errors however when I go to load the device tree I get the following:

echo BB-APA-01 > slots
[ 8122.326385] bone_capemgr bone_capemgr: part_number ‘BB-APA-01’, version ‘N/A’
[ 8122.333614] bone_capemgr bone_capemgr: slot #5: override
[ 8122.339116] bone_capemgr bone_capemgr: Using override eeprom data at slot 5
[ 8122.346184] bone_capemgr bone_capemgr: slot #5: ‘Override Board Name,00A0,Override Manuf,BB-APA-01’
[ 8122.369433] __of_changeset_entry_apply: add_property failed @/ocp/serial@481aa000/pinctrl-names
[ 8122.378353] of_changeset_apply: Error applying changeset (-17)
[ 8122.384609] __of_overlay_create: of_changeset_apply() failed for tree@/
[ 8122.391429] bone_capemgr bone_capemgr: slot #5: Failed to create overlay
-bash: echo: write error: File exists

My dts file is essentially the same as I had it in 3.8.x except for changing uart numbers to index from 0 instead of 1 as I’ve read that changed.

This custom device tree uses pins reserved for HDMI so I did added teh disable option to /boot/uEnv.txt:

cape_disable=capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN

What else do I need to update in my .dts or do to get a custom device tree to load?

Thanks,

RobertCNelson · May 9, 2016, 6:16pm

Hi,

In the process of migrating from 3.8.x to 4.1.21 and trying to get my
device tree to load manually (eventually to load on boot).

As I understand it device trees are supported in 4.1.x -- yes?

I the the .dts compiles with out errors however when I go to load the
device tree I get the following:

echo BB-APA-01 > slots
[ 8122.326385] bone_capemgr bone_capemgr: part_number 'BB-APA-01', version
'N/A'
[ 8122.333614] bone_capemgr bone_capemgr: slot #5: override
[ 8122.339116] bone_capemgr bone_capemgr: Using override eeprom data at
slot 5
[ 8122.346184] bone_capemgr bone_capemgr: slot #5: 'Override Board
Name,00A0,Override Manuf,BB-APA-01'
[ 8122.369433] __of_changeset_entry_apply: add_property failed
@/ocp/serial@481aa000/pinctrl-names
[ 8122.378353] of_changeset_apply: Error applying changeset (-17)
[ 8122.384609] __of_overlay_create: of_changeset_apply() failed for tree@/
[ 8122.391429] bone_capemgr bone_capemgr: slot #5: Failed to create overlay
-bash: echo: write error: File exists

This also could me you used the wrong dtc compiler..

Use the one this one builds:

github.com

beagleboard/bb.org-overlays/blob/master/dtc-overlay.sh

#!/bin/sh -e

DIR="$PWD"

check_dpkg () {
	LC_ALL=C dpkg --list | awk '{print $2}' | grep "^${pkg}" >/dev/null || deb_pkgs="${deb_pkgs}${pkg} "
}

dtc_git_build () {
	project="dtc"
	server="https://git.kernel.org/pub/scm/utils/dtc/dtc.git"

	if [ ! -d ${HOME}/git/ ] ; then
		mkdir -p ${HOME}/git/ || true
	fi

	if [ ! -f ${HOME}/git/${project}/.git/config ] ; then
		git clone ${server} ${HOME}/git/${project}/
	fi

This file has been truncated. show original

My dts file is essentially the same as I had it in 3.8.x except for
changing uart numbers to index from 0 instead of 1 as I've read that
changed.

This custom device tree uses pins reserved for HDMI so I did added teh
disable option to /boot/uEnv.txt:

cape_disable=capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN

this ^ doesn't do anything..

Read, section: BBB compatibility issues:

github.com

beagleboard/bb.org-overlays/blob/master/readme.md

Build Status

 [![Build Status](http://gfnd.rcn-ee.org:8080/buildStatus/icon?job=beagleboard_overlays/master)](http://gfnd.rcn-ee.org:8080/job/beagleboard_overlays/job/master/)


Users:
------------

Install or Update bb-cape-overlays debian package (pre installed on: Debian Stretch/Buster & Ubuntu Bionic images)

    sudo apt update ; sudo apt install bb-cape-overlays

Supported Linux Kernels:
------------

Pre-built kernels: (there are multiple options avaiable)

    cd /opt/scripts/tools
    git pull

This file has been truncated. show original

Regards,

Matt3 · May 9, 2016, 7:33pm

Yes I do believe I have the right version – as I followed your instructions in bb.org-overlays

here is the result of a version check:
root@arm:/lib/firmware# dtc --version
Version: DTC 1.4.1-g1e75ebc9

To compile an overlay I did
dtc -O dtb -o BB-APA-01-00A0.dtbo -b 0 -@ BB-APA-01-00A0.dts

Then I placed the output in /lib/firmware

Referring to https://github.com/beagleboard/bb.org-overlays/blob/master/readme.md
I changed my uEnv.txt to contain
dtb=am335x-boneblack-emmc-overlay.dtb

Stll getting this:
[ 229.625505] bone_capemgr bone_capemgr: part_number ‘BB-APA-01’, version ‘N/A’
[ 229.633234] bone_capemgr bone_capemgr: slot #4: override
[ 229.638620] bone_capemgr bone_capemgr: Using override eeprom data at slot 4
[ 229.655322] bone_capemgr bone_capemgr: slot #4: ‘Override Board Name,00A0,Override Manuf,BB-APA-01’
[ 229.676441] __of_changeset_entry_apply: add_property failed @/ocp/serial@481aa000/pinctrl-names
[ 229.676462] of_changeset_apply: Error applying changeset (-17)
[ 229.695456] __of_overlay_create: of_changeset_apply() failed for tree@/
[ 229.702544] bone_capemgr bone_capemgr: slot #4: Failed to create overlay
sh: echo: I/O error

Matt3 · May 9, 2016, 11:25pm

Fixed this issue – was a <&uart*> number I missed changing… doh

I can now manually add the device tree :

cat /sys/devices/platform/bone_capemgr/slots
0: PF---- -1
1: PF---- -1
2: PF---- -1
3: PF---- -1
4: P-O-L- 0 Override Board Name,00A0,Override Manuf,BB-APA-00A0,Override Manuf,BB-APA-01

How do I bake this into my kernel such that it loads at boot?

RobertCNelson · May 9, 2016, 11:36pm

sudo update-initramfs -uk `uname -r`

*.dtbo's from /lib/firmware/ get copied to the initramfs..

then add BB-APA-01 into /boot/uEnv.txt under the v4.1.x kernel section on
loading overlays..

Regards,

Matt3 · May 9, 2016, 11:59pm

Got the command to go but don’t quite follow you on the

then add BB-APA-01 into /boot/uEnv.txt under the v4.1.x kernel section on loading overlays…

My uEnv.txt looks like this right now:
cat /boot/uEnv.txt
uname_r=4.1.23-ti-rt-r60
uuid=8b83ed28-d947-4fda-b607-d5c5faf3dbe5
dtb=am335x-boneblack-emmc-overlay.dtb

Am I missing something here in uEnv.txt?

Do I simply add this to /boot/uEnv.txt:

bone_capemgr.enable_partno=BB-APA-01

RobertCNelson · May 10, 2016, 12:08am

cape_enable=bone_capemgr.enable_partno=BB-APA-01

Regards,

Matt3 · May 10, 2016, 3:59pm

As always thanks for the help Robert!

That solved it!