RootFS from Squashfs to Jffs2

Hi,
i have a problem to convert the filesystem in JFFS2 format to insert a library in its space.
Edit through ‘flpart’ create boot errors.

Gently someone can explain clearly how to do.

thanks

I have find a solution.
If someone can serve:
instead of changing the format of the filesystem I created a project in the IDE where I loaded the libraries and then I loaded it in UBoot.