How to enable printf with float argument?

[profOnno]

In the libopencm3-examples repository there is a usart_printf example. When compiling the examples this printf("float: %f", 3.21f); works as expected.

Using this repository (libopencm3-template), the printf("float: %f", 3.21f); doesn't do anything (skips the line). Some searching did reveal you should add LDFLAGS += -u _printf_float to the make file. This didn't
work for me. Any pointers on how to make this work?

update:
Got it working, added LDFLAGS += -u _printf_float to the Makefile. Not sure what went wrong the first time.

[karlp]

Doesn't appear to be anything else needed here :)