It doesn't 100% boot off the SD card, it relies on those 3 copies of the flash boot r/o file-system, and being able to find a few hundred KB of flash which is still reliable (out of 128MB - so not such a big ask - and it will move files around if it detects weak blocks, which on a 'full' file-system quickly ends up retrying bad ones, but an empty one should be good). That space is for a number of directories and a large number of sym-links, along with my SD driver itself.
http://www.qnx.com/developers/docs/6...o/bookset.html
This is the documentation for "our" unit's operating system. Go to utilities and look up etfsctl. I personally have never had to use it, sorry, so you will be the first! Yours is currently corrupt enough to not be able to get anything back off it now, so there's no real risk in trying (I don't think).
To answer your question about what I've posted on github, no not that simple, there are many sym-links and directories (and a hand full of real files) that have to be put back, where I would create a script to do most of it. The files are there because it's most likely corruptions are in the large files, not the small links or fs-structures.
One thing at a time though, if this unit's flash memory is bad in an unfortunate spot, we may be wasting our time, so getting a mountable file-system back in place is the first step.