Dear Kai, >This error seems to claim there being something wrong in the '>../src/XXXX.c', line #1, on the very first source line. What > here really is? Well, it is a comment ;-) Thanks for -save-temps tip! I will remember to use it! >> If the Cortex-M0 CPU doesn't understand any '-marm' code, where on >> earth the optional '-marm' code would be run? Ah, that is the point, this toolchain is planned to be used for other ARM CPUs, i.e. arm7tdmi. And those CPU may run interworked code! There cannot be any other lib except armv6-m, for Cortex-M0 because it is a very dumb 16-bit instruction set CPU (and very cheap at the same what really helps :-) Regards, Andriy