| Baselibc |
| ======== |
| |
| 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. |
| |
| The code is based on klibc and tinyprintf modules, and licensed under |
| the BSD license. |
| |
| Baselibc comes from https://github.com/PetteriAimonen/Baselibc.git |
| |
| Description |
| ~~~~~~~~~~~ |
| |
| Mynewt OS can utilize libc which comes with 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. |
| |
| How to switch to baselibc |
| ~~~~~~~~~~~~~~~~~~~~~~~~~ |
| |
| 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 ``boot`` uses baselibc. Its project description file |
| ``boot.yml`` looks like the following: |
| |
| .. code-block:: console |
| |
| project.name: boot |
| project.identities: bootloader |
| project.pkgs: |
| - libs/os |
| - libs/bootutil |
| - libs/nffs |
| - libs/console/stub |
| - libs/util |
| - libs/baselibc |
| |
| List of Functions |
| ~~~~~~~~~~~~~~~~~ |
| |
| Documentation for libc functions is available from multiple places. One |
| example are the on-line manual pages at |
| `https://www.freebsd.org/cgi/man.cgi <#https://www.freebsd.org/cgi/man.cgi>`__. |
| |
| baselibc supports most libc functionality; malloc(), printf-family, |
| string handling, and conversion routines. |
| |
| There is some limited functionality and support for |
| floating point numbers and 'long long', but contributions are always welcome! |
