Long story short, it will no longer flash the factoryfs.img of anything I try and make it flash (it fails at 42%, oddly). clockworkmod recovery mode still works (version 184.108.40.206), however I did not make a backup of the phone while it was in a workable state. When I attempt to install an update.zip file using clockworkmod I get an assertation failed error whinging that my build.prop file does not contain the proper device identifier string (Seems I managed to bork that, too).
I had the idea that I might be able to edit a factoryfs.img of an existing ROM and put in a build.prop file that has the required property, however have been unable to mount it. Those things seem to be structured oddly.
Using Odin is not an option. I do not have access to a windows computer.
Does someone have a clockworkmod backup of a working SGS2I9100, then? It is my hope that if I can procure one of these and stick it on the SD card clockworkmod will be able to load it (And then, provided this fixes the whole build.prop thing, I can install something from a zip).
Does there exist a way of editing build.prop from the computer? All I can seem to find are instructions of the form "Install this app and do it from your phone" - not much use when the thing won't boot.
Does anyone have any thoughts about why heimdall no longer works? It has worked before, but now, as I said, fails consistently at 42% of the way through factoryfs.img for whatever ROM I try to use.
Any other ideas? This thing's been bricked for a while now and I'm fresh out of ideas on how to fix it. Heimdall does seem to still be able to flash other things (just not factoryfs). So other plausible solutions would seem to be some way of flashing a working build.prop with heimdall or some update.zip of a working system that precludes the entirely sensible assertations that check the file.