Here is a Makefile for building various portlibs for 3DS. You need to first build zlib and install it. Then you can build the other portlibs.
$ make zlib
$ make install-zlib
$ make <targets>
$ make install
This will install the portlibs to $DEVKITPRO/portlibs/armv6k. If this is a
privileged location, you will need to sudo make install-zlib and sudo make install in order for the portlibs to be installed.
Currently supports the following portlibs:
- freetype (requires zlib)
- libexif
- libjpeg-turbo
- libpng (requires zlib)
- sqlite
- zlib
- mxml
- expat
- libxml2
- jansson
- physfs
- libmad
- libogg
- libvorbis
- giflib
- bzip2