Implementation of Read-Only System Files and Mobile and I/O POST/GET Service Removal with RutOS 7.14

NETWORKING SOLUTIONS
4

Hello,

We won’t use writable OverlayFS for the root file system anymore. This means there will be only a few directories that are writable:

  • /etc - writable overlayfs with lowerdir of ro /etc
  • /usr/local - writable overlayfs with lowerdir of ro /usr/local
  • /log - writable jffs2 (or ubifs) partition
  • /tmp - writable tmpfs, non-persistent
  • /mnt - symlink to /tmp
  • /var - symlink to /tmp
  • /overlay - writable jffs2 or ubifs where overlayfs upperdir of /etc and /usr/local are stored
  • /ext - only on SME (Storage Memory Expansion) enabled: writable ext4 or exfat where overlayfs upperdir of /usr/local is stored
  • /usr/share - symblink to /usr/local/share

Anything else - won’t be writable. That includes binaries in /bin /sbin /usr/bin /usr/sbin; libraries in /lib /usr/lib.

Package manager will install packages into /usr/local directory. PATH environment variable is also updated to launch binaries from /usr/local path.

For example, if you had some files or scripts in /root directory, then you won’t be able to put them there with RUTOS 7.14. Instead, you should place them somewhere in /usr/local.

If you had replaced system binaries: let’s say you have modified and built netifd from the SDK, then uploaded it into the device and replaced original library at /sbin/netifd. This won’t work either, however, you will be able to place it at /usr/local/bin/netifd, then modifying /etc/init.d/network to use /usr/local/bin/netifd and not /sbin/netifd.

Best regards,

2 Likes