for these kind of low level things, it's best to turn off all compiler optimizations and os specific features. if you run gcc -V or something hten it will dump

for these kind of low level things, it's best to turn off all compiler optimizations and os specific features. if you run gcc -V or something hten it will dump it's default flags for the distro you are on. What i ususally do is create a cross compiler with nothing enabled for these kinds of projects. This saves a lot of sifting and disabling options and optimizations. If you have a bunch of inline assembly and such things, optimizations can be really killing.