Standalone simple printf implementation using GCC for ARM.
It doesn't require any external library including standard C library.
It doesn't use stdarg.h / varargs to implement.
It doesn't support printing floating-points (yet).
printf.c and its header file is all needed. You need to define PRINTF_NAME to name printf instance (to avoid possible name conflicts) and provide a PRINTF_PUTC implementation which should deliver a single char to requested medium. PRINTF_PUTC should gracefully handle \n that is if \n needs to be swapped with \r\n, it is PRINTF_PUTC's task to do that.
See Makefile for examples, it comes with some example builds like linux and memtest.
linux target is a standalone application using system calls to print directly to stdout.
memtest target is a simple application using a buffer to test functionality of printf implementation.