After the previous previous post I spotted a new rootfs from Adapteva so I dropped that onto my sdcard. Unfortunately ... I dropped it onto the wrong sdcard and overwrote my original one. It's been a few days of stupid mistakes. Somehow I ended up with a running-enough system.
I found a pile of pointer size related bugs in zcl (obvious in hindsight) and made a bit of a mess trying to track down a bug that i'm pretty sure is just in the OpenCL driver (although it was a function that should've just returned not-supported so it isn't expected to work). There are some other missing bits and unexplained problems and it looks like only OpenCL 1.0 is partially implemented to start with (despite what cl.h claims) so I had to add some more version filtering. I think 'needs work' might be an apt description.
I just tried the epiphany driver but i just got unending reams of stuff about registers so i can't tell if anything worked (actually it's pretty clear it didn't run beyond compilation).
While I was doing the rootfs thing I also managed to compile the sdk on my main machine (more specifically just the GNU toolchain). I tried building it in a separate build directory the GNU-way but that doesn't seem to be supported and I just had to use the silent build script instead.
Unfortunately none of this trouble-shooting and repeated stupid mistakes really got me anywhere or was particularly fun. I think it was just the morbid curiosity that kept me poking until beyond 6am (15 minutes ago).