This page mainly introduces add user 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#############################
## 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 node boot_user_args=, please make sure the bootargs are spilt with space.

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

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