1 files changed, 89 insertions, 2 deletions

diff --git a/contrib/wpa_supplicant/doc/porting.doxygen b/contrib/wpa_supplicant/doc/porting.doxygen
index db64a11..581da48 100644
--- a/contrib/wpa_supplicant/doc/porting.doxygen
+++ b/contrib/wpa_supplicant/doc/porting.doxygen
@@ -5,14 +5,62 @@
 hardware (board, CPU) and software (OS, drivers) targets. It is
 already used with number of operating systems and numerous wireless
 card models and drivers. The main %wpa_supplicant repository includes
-support for Linux, FreeBSD, and Windows. In addition, at least VxWorks
-and PalmOS are supported in separate repositories. On the hardware
+support for Linux, FreeBSD, and Windows. In addition, at least VxWorks,
+PalmOS, Windows CE, and Windows Mobile are supported in separate
+repositories. On the hardware
 side, %wpa_supplicant is used on various systems: desktops, laptops,
 PDAs, and embedded devices with CPUs including x86, PowerPC,
 arm/xscale, and MIPS. Both big and little endian configurations are
 supported.
 
 
+\section ansi_c_extra Extra functions on top of ANSI C
+
+%wpa_supplicant is mostly using ANSI C functions that are available on
+most targets. However, couple of additional functions that are common
+on modern UNIX systems are used. Number of these are listed with
+prototypes in common.h (the #ifdef CONFIG_ANSI_C_EXTRA block). These
+functions may need to be implemented or at least defined as macros to
+native functions in the target OS or C library.
+
+Many of the common ANSI C functions are used through a wrapper
+definitions in os.h to allow these to be replaced easily with a
+platform specific version in case standard C libraries are not
+available. In addition, os.h defines couple of common platform
+specific functions that are implemented in os_unix.c for UNIX like
+targets and in os_win32.c for Win32 API. If the target platform does
+not support either of these examples, a new os_*.c file may need to be
+added.
+
+Unless OS_NO_C_LIB_DEFINES is defined, the standard ANSI C and POSIX
+functions are used by defining the os_*() wrappers to use them
+directly in order to avoid extra cost in size and speed. If the target
+platform needs different versions of the functions, os.h can be
+modified to define the suitable macros or alternatively,
+OS_NO_C_LIB_DEFINES may be defined for the build and the wrapper
+functions can then be implemented in a new os_*.c wrapper file.
+
+common.h defines number of helper macros for handling integers of
+different size and byte order. Suitable version of these definitions
+may need to be added for the target platform.
+
+
+\section configuration_backend Configuration backend
+
+%wpa_supplicant implements a configuration interface that allows the
+backend to be easily replaced in order to read configuration data from
+a suitable source depending on the target platform. config.c
+implements the generic code that can be shared with all configuration
+backends. Each backend is implemented in its own config_*.c file.
+
+The included config_file.c backend uses a text file for configuration
+and config_winreg.c uses Windows registry. These files can be used as
+an example for a new configuration backend if the target platform uses
+different mechanism for configuration parameters. In addition,
+config_none.c can be used as an empty starting point for building a
+new configuration backend.
+
+
 \section driver_iface_porting Driver interface
 
 Unless the target OS and driver is already supported, most porting
@@ -118,4 +166,43 @@ also possible to do this when a network interface is being
 enabled/disabled if it is desirable that %wpa_supplicant processing
 for the interface is fully enabled/disabled at the same time.
 
+
+\section simple_build Simple build example
+
+One way to start a porting project is to begin with a very simple
+build of %wpa_supplicant with WPA-PSK support and once that is
+building correctly, start adding features.
+
+Following command can be used to build very simple version of
+%wpa_supplicant:
+
+\verbatim
+cc -o wpa_supplicant config.c eloop.c common.c md5.c rc4.c sha1.c \
+	config_none.c l2_packet_none.c tls_none.c wpa.c preauth.c \
+	aes_wrap.c wpa_supplicant.c events.c main_none.c drivers.c
+\endverbatim
+
+The end result is not really very useful since it uses empty functions
+for configuration parsing and layer 2 packet access and does not
+include a driver interface. However, this is a good starting point
+since the build is complete in the sense that all functions are
+present and this is easy to configure to a build system by just
+including the listed C files.
+
+Once this version can be build successfully, the end result can be
+made functional by adding a proper program entry point (main*.c),
+driver interface (driver_*.c and matching CONFIG_DRIVER_* define for
+registration in drivers.c), configuration parser/writer (config_*.c),
+and layer 2 packet access implementation (l2_packet_*.c). After these
+components have been added, the end result should be a working
+WPA/WPA2-PSK enabled supplicant.
+
+After the basic functionality has been verified to work, more features
+can be added by linking in more files and defining C pre-processor
+defines. Currently, the best source of information for what options
+are available and which files needs to be included is in the Makefile
+used for building the supplicant with make. Similar configuration will
+be needed for build systems that either use different type of make
+tool or a GUI-based project configuration.
+
 */