Most of the big chip vendors provide a libc implementation along with the proprietary compilers that they maintain for their chips. On the TI MSP430, I've had s

Most of the big chip vendors provide a libc implementation along with the proprietary compilers that they maintain for their chips. On the TI MSP430, I've had some projects that were too big to fit into flash if I used the libc (newlib) that's bundled with the open source MSP430-GCC compiler[1]. By contrast, if I compiled with the proprietary TI compiler[2] and its libc, the binary was small enough to fit. My experience is a bit dated at this point, so newlib and the GCC fork may have improved enough to reach parity by now. The dominance of GCC and LLVM on x86[-64] machines has conditioned many of us to take great open source build toolchains for granted, but embedded systems are comparatively the wild west - there are still a lot of proprietary build toolchains out there. Obviously this is a negative if you're committed to using open source tools, but one positive is that it's a niche where companies can still make money selling compilers (and therefore employing engineers who work on compilers). [1] http://www.ti.com/tool/MSP430-GCC-OPENSOURCE http://www.ti.com/tool/MSP430-GCC-OPENSOURCE [2] http://www.ti.com/tool/MSP-CGT http://www.ti.com/tool/MSP-CGT