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<h1 id="baselibc">Baselibc</h1>
<p>Baselibc is a very simple libc for embedded systems geared primarily for 32-bit microcontrollers in the
10-100kB memory range. The library of basic system calls and facilities compiles to less than 5kB total
on Cortex-M3, and much less if some functions aren't used.</p>
<p>The code is based on klibc and tinyprintf modules, and licensed under the BSD license.</p>
<p>Baselibc comes from https://github.com/PetteriAimonen/Baselibc.git</p>
<h3 id="description">Description</h3>
<p>Mynewt OS can utilize libc which comes with the compiler (e.g. newlib bundled with some binary
distributions of arm-none-eabi-gcc). However, you may choose to replace the libc with baselibc
for a reduced image size. Baselibc optimizes for size rather than performance, which is usually
a more important goal in embedded environments.</p>
<h3 id="how-to-switch-to-baselibc">How to switch to baselibc</h3>
<p>In order to switch from using libc to using baselibc you have to add the baselibc pkg as a dependency
in the project pkg. Specifying this dependency ensures that the linker first looks for the functions
in baselibc before falling back to libc while creating the executable. For example, project <code>boot</code>
uses baselibc. Its project description file <code>boot.yml</code> looks like the following:</p>
<div class="codehilite" style="background: #ffffff"><pre style="line-height: 125%;"><span></span><code> project.name: boot
project.identities: bootloader
project.pkgs:
- libs/os
- libs/bootutil
- libs/nffs
- libs/console/stub
- libs/util
- libs/baselibc
</code></pre></div>
<h3 id="list-of-functions">List of Functions</h3>
<p>Documentation for libc functions is available from multiple places. One example is the on-line manual
pages at <a href="#https://www.freebsd.org/cgi/man.cgi">https://www.freebsd.org/cgi/man.cgi</a>.</p>
<p>baselibc supports most libc functionality; <code>malloc()</code>, printf-family, string handling, and conversion routines.</p>
<p>There is some functionality which is not available, e.g. support for floating point numbers, and limited support for 'long long'.</p>
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