I've looked at which kernels support getrandom: 3.16: amd64, i386, ia64, sparc 3.17: arm, s390, arm64, microblaze, mips, hppa, m68k, powerpc 3.18: xtensa 4.0: avr32 4.1: blackfin, alpha 4.3: cris
so most architectures lack it even in jessie (3.16). And ARM is notorious for vendor kernels that might (hopefully) get minor version upgrades but never move past their original major version. Like, a not too shabby box I run armhf archive rebuilds on is stuck on (regularly updated) 3.8. -- An imaginary friend squared is a real enemy.
