How do I link math libraries using GCC newlib-nano used for math functions like ceil/floor?
newlib-nano doesn't include all library functions by default to save code space and RAM. To use certain math library functions, you must include libm.a.
GCC automatically assumes libraries are of the form lib<name>.a. For example, the math library, m, becomes libm.a.
In Studio, project properties, C/C++ Build->Settings->GNU ARM C Linker->Libraries->Libraries (-l), add a library, "m" (no quotes).