C errors

So the error
Undefined symbols:
"_main", referenced from:
start in crt1.10.5.o
ld: symbol(s) not found
collect2: ld returned 1 exit status
make: *** [additional] Error 1

is pretty hard to understand. The main takeaway: you need a main function. Basically, you either forgot to include a main function, or you forgot to compile this alongside another file that does have a main function.