genode/repos/libports/doc/libc.txt

The C library of the Genode OS Framework is based on the code of FreeBSD. The
original code is available at the official FreeBSD website.

:FreeBSD website: [http://www.freebsd.org]

Currently, the libc supports the x86_32, x86_64 and ARM architectures. Support
for other architectures is planned as future addition.

Usage
-----

Before the libc is ready to use, the original FreeBSD source codes must be
downloaded and integrated with the Genode build system. The tool 'prepare_port'
automates this task. Please make sure to have Subversion installed. Then issue
the following command:

! ./tool/ports/prepare_port libc

To use the libc in your application, add 'libc' to the 'LIBS' declaration in
your build-description file. This declaration will make the libc headers
available for the include path of your target and link the C library. When
building, make sure that the 'libports' repository is included in your build
configuration ('<build-dir>/etc/build.conf').

Limitations
-----------

The current version of the C library is not entirely thread-safe.
In particular, the 'FILE' stream API ('fopen', 'fread', ...) must not be
used from multiple threads.

The back end does not cover all features of FreeBSD. If an unsupported
functions is called (see 'dummies.cc'), you will see an message in your debug
output:
! <function-name> called, not yet implemented!

Some of the back-end functions implemented in the other files have
dummy semantics but have to remain quiet because they are called from low-level
libc code.