compilation warnings in ld.exe

hi all, i got my neutrino (arduino zero compatible) and started with it, but when i upload my code, i ge this warning 3 times:

rm-none-eabi/bin/ld.exe: warning: changing start of section .bss by 4 bytes

and part of my code won't work, though it does work on my arduino due..

all of the code (including needed libraries) is here: GitHub - 8bitbunny/Zerowatch: arduino compatible smartwatch

can anyone help me?