вот: /arm-none-eabi/lib/thumb/v6-m/nofp/libg.a(lib_a-init.o): in function `__libc_init_array':
init.c:(.text.__libc_init_array+0x18): undefined reference to `_init'
collect2: error: ld returned 1 exit status
make: *** [ARMCMx/compilers/GCC/mk/rules.mk:217: build/ch.elf] Error 1
"make all" terminated with exit code 2. Build might be incomplete.