O'Reilly logo

Linux: Embedded Development by Chris Simmonds, Alex González, Alexandru Vaduva

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Making the root filesystem read-only

You need to make your target device able to survive unexpected events including file corruption, and still be able to boot and achieve at least a minimum level of function. Making the root filesystem read-only is a key part of achieving this ambition because it eliminates accidental over-writes. Making it read-only is easy: replace rw with ro on the kernel command line or use an inherently read-only filesystem such as squashfs. However, you will find that there are a few files and directories that are traditionally writable:

  • /etc/resolv.conf: This file is written by network configuration scripts to record the addresses of DNS name servers. The information is volatile, so you simply have to make it a symlink ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required