I managed to get the common-shaders “working” on the raspberry pi. You can convert the shaders to GLSL on a x86 based system – the conversion doesn’t compile them to x86 binaries. I used my debian laptop and the python script from the retroarch git repository – but I’m sure any distro would suffice.
While the shaders work, performance suffers with all but the most trivial shaders – they really highlight how many of these emulators (picodrive/pocketsnes) are just barely working on the pi.
I found the crt/crt.glsl,crt-highgamma.glsl,crt-normalgamma.glsl seemed to provide a passable CRT type display without hindering performance too badly. Otherwise using an interlace + smoothing shader like hqx/eagle kind of worked too.
Hope that helps.
edit: for any shader, drop scale to 1x – it runs poorly if you leave it on “don’t care” or a higher value. Currently running Sonic 3 smoothly in picodrive with crt-highgamma.glsl and RPi OC’ed to 1ghz.