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

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=

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

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

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

consoles=console=ttyS0,921600 console=tty0

After reboot system, we can check current linux kernel bootargs

$ cat /proc/cmdline