Whoo, this was hard. I was working on extracting firmware and other files from the SCH-i909 ROM build. However, instead of presenting me with lovely .img files, the .tar file only contained .rfs files. WTF?
Googling had no answer. I could NOT make an .rfs file. Until I discovered this tutorial on XDA.
According to the poster, it’s simple to mount .rfs files in Linux.
Step 1: Create a temporary directory.
Step 2: Mount the .rfs file itself.
sudo mount -o loop <filename>.rfs temp/
Step 3: Profit.
I still haven’t managed out how to repackage these .rfs files, but that’s a post for the future. Stay tuned.
EDIT: I’m an idiot. How do I unmount the file?
sudo umount temp/