How to change the the kernel boot cmdline without reflashing the entire Debian microSD image?

Products Support DragonBoard410c
#1

Is it possible to change the the kernel boot cmdline without reflashing the entire Debian microSD image?

PRETTY_NAME="Debian GNU/Linux 11 (bullseye)"
NAME="Debian GNU/Linux"
VERSION_ID="11"
VERSION="11 (bullseye)"
VERSION_CODENAME=bullseye

I currently have the following defaults:
linaro@DragonBoard**:/proc$ cat /proc/cmdline**

root=PARTLABEL=rootfs console=tty0 console=ttyMSM0,115200n8 androidboot.emmc=true androidboot.serialno=43c142d4 androidboot.baseband=apq mdss_mdp.panel=1:dsi:0:qcom,mdss_dsi_hx8394d_720p_video:1:none

I need to to add systemd.unified_cgroup_hierarchy=0 to the kernel cmdline to be able to launch Docker containers.

If this is possible, what is the procedure to make this change?

Since I find no presence of grub, what is the bootloader in used with the boot from microSD Debian image?

#2

As I said refer to HDMI screen when device was booted without HDMI - #8 by Nadav_B, if you have a network connection, you should be able to download that tool.

The command line is part for the boot image which is a blob containing the kernel, dts, cmdline, etc… the bootloader is LK (little kernel).

#3

Hi Loic,

Success!!! Thank you!

linaro@DragonBoard**:~$ sudo systemctl start docker**

linaro@DragonBoard**:~$ sudo docker run hello-world**

Hello from Docker!
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
1. The Docker client contacted the Docker daemon.

2. The Docker daemon pulled the “hello-world” image from the Docker Hub.
(arm64v8)

3. The Docker daemon created a new container from that image which runs the
executable that produces the output you are currently reading.

4. The Docker daemon streamed that output to the Docker client, which sent it
to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
$ docker run -it ubuntu bash

Share images, automate workflows, and more with a free Docker ID:
https://hub.docker.com/

For more examples and ideas, visit:
Orientation and setup | Docker Documentation
linaro@DragonBoard**:~$**

linaro@DragonBoard**:~$ cat /proc/cmdline**

root=PARTLABEL=rootfs console=tty0 console=ttyMSM0,115200n8 androidboot.emmc=true androidboot.serialno=43c142d4 androidboot.baseband=apq mdss_mdp.panel=1:dsi:0:qcom,mdss_dsi_hx8394d_720p_video:1:none systemd.unified_cgroup_hierarchy=0

androidboot.emmc=true androidboot.serialno=43c142d4 androidboot.baseband=apq

linaro@DragonBoard**:~$**

Yes, I have the Ubuntu bash shell suggested in the Docker hello-world running as well.

Thanks again for your help!