Sansa e200 reverse bootloader?

[bman]

Is there a reverse bootloader (which loads the original  firmware automatically, and instead you have to hold a button to boot rockbox) that's compatible with a new-ish version of rockbox? Or would an old bootloader work fine?

[saratoga]

I think there was for the e200v1 at least. Not sure how well it works with modern versions though.