在yocto中创建一个只读文件

Question

How do I create a read-only file in yocto.

I have given only read permissions to all groups in the bbappend file

do_install_append() {
    install -m 0444 os-release ${D}${sysconfdir}/
}

ls -al /etc/os-release correctly list the permissions, but I am able to modify the file in root user.

How can I avoid this behavior and make it read-only

Answer 1

I tested this on ubuntu 18.04:

erni@Sally:~$ date >> test.txt
erni@Sally:~$ echo test >> test.txt
erni@Sally:~$ chmod 444 test.txt 
erni@Sally:~$ echo test2 >> test.txt
bash: test.txt: Permission denied
erni@Sally:~$ sudo sh -c 'echo test3 >> test.txt'
erni@Sally:~$ cat test.txt 
gio  6 dic 2018, 17.28.42, CET
test
test3

As you can see you can still modify a protected file in ubuntu