I'm trying to track down the executables/libraries that are behind the "Illegal instruction" errors I am seeing on my Tegra 2 devices. It seems a given that this is due to some packages from the GL stack (Mesa, libglvnd, etc.) having been build with assumptions of NEON always being present, but I'm trying to figure out a way to determine this definitively.
I have tried the approach along the lines of:
objdump -Ds $file | grep -E 'vadd.|vmul.'
since vadd and vmul are both NEON assembly instructions, but this seems to flag up nearly everything, most of which is in fact working (e.g. Firefox 52.x).
So either my approach is wrong or there are many binaries that do some kind of runtime detection and selectively use NEON if supported by the hardware.
The reason i am looking into this is because gdm doesn't work without working GL (even software mesa GL). It works on my Chromebook without hardware accelerated drivers, but doesn't work on my Tegra laptop without accelerated drivers. On the Chromebook (Exynos) glxgears runs (albeit slowly), but on Tegra, it crashes with "Illegal instruction".
I tried rebuilding libglvnd and mesa on the local machine in a hope that NEON capability is auto-detected but that doesn't seem to have made any difference.
Any advice/suggestions/insights gratefully received.