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products:sbc:common:configurations:user-config

Kernel Bootargs User Config

Introduction

This page mainly introduces how-to user can customize linux kernel bootargs under Ubuntu.

How-to Customize Linux Kernel Bootargs

You can edit file /boot/uEnv.txt to add the user bootargs.

The default file contents are similar as below:

$ cat /boot/uEnv.txt 
#############################DO NOT TOUCH THIS OPTION#############################
rootdev=root=UUID=a92f7f2f-0d4a-4607-a45a-4549cfe71036
partitiontype=partition_type=generic
#############################DO NOT TOUCH THIS OPTION#############################
## Setup console
consoles=console=ttyS0,921600 console=tty0
 
## Setup FAN mode
fan_mode=auto
 
## Add user args here, spilt with space.
## e.g. Add bootargs 'test1=111 test2=222'
## boot_user_args=test1=111 test2=222
boot_user_args=

Normal Bootargs

You can append your bootargs to the configuration boot_user_args=.

e.g. Add bootargs cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory systemd.unified_cgroup_hierarchy=0, the variable boot_user_args= should be as below:

boot_user_args=cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory systemd.unified_cgroup_hierarchy=0

Console Bootargs

This configuration is suitable for only the 5.15 kernel.

You can change the linux UART pins for normal usage by modifying the configuration console=

UART mode Configuration
Configure the UART for linux debug consoles=console=ttyS0,<baud rate> console=tty0
Configure the UART for general usage consoles=console=tty0

eg. Enable linux UART console with 921600 baud rate should be as below:

consoles=console=ttyS0,921600 console=tty0
Model Baudrate
VIM3/VIM3L 115200
VIM4/VIM1S 921600

Please make sure the bootargs are split with space and don't add quotation marks.

Save the file and reboot to take effect.

How-to Check Linux Kernel Bootargs

After reboot system, we can check current linux kernel bootargs

$ cat /proc/cmdline
Last modified: 2023/11/07 05:54 by sravan