simple no-float 32-bit printf
Does everything I need it to. Will fix bugs as I come across them.
Compiles down to 1370 bytes on arm-none-eabi-gcc with -Os optimizations.
mprintf is about 400 lines of code (per David A. Wheeler's SLOCCount)
Supports b, c, d, i, p, s, u, X, x, and % conversion flags, minimum field widths, and 0- +# format flags.
Designed with Cortex-M microcontrollers in mind, but there's no microcontroller-specific code in the file.
I also included testing using Greatest from https://github.com/silentbicycle/greatest. There's a number of tests that compare mprintf against the standard printf.