diff --git a/docs/x11/readme-nanox.txt b/docs/x11/readme-nanox.txt new file mode 100644 index 0000000000..3698cf4ac0 --- /dev/null +++ b/docs/x11/readme-nanox.txt @@ -0,0 +1,201 @@ +Nano-X port +=========== + +What is it? +=========== + +The Nano-X port is based on the wxX11 code, and therefore shares +almost all of wxX11's code, including the use of the wxUniversal +widget set. Nano-X is the X-like API of the overall Microwindows +project, which also has a WIN32 API. + +The Microwindows web site is at + + http://microwindows.org/ + +Nano-X is intended to work on devices with very small amounts +of memory. wxWindows is quite a large library, so if your +memory is measured in KB instead of MB you will need to use +an alternative library, such as FLTK. However, with memory +capacity increasing all the time, wxWindows could become +an appropriate embedded GUI solution for many projects. +Also, it's possible to think of ways to cut wxWindows +further down to size, such as disabling advanced controls +or rewriting utility functions. See the section on code size +below. + +An alternative to using Nano-X is to use the standard +wxX11 port with Tiny-X, which (as I understand it) +maintains the Xlib API while being sufficiently cut +down to run on small devices, such as the iPAQ. +The Familiar Linux Distribution contains Tiny-X. See: + + http://handhelds.org/mailman/listinfo/familiar + +Building wxNano-X +================= + +Building is as per the instructions for wxX11 (see readme.txt, +install.txt) but passing --enable-nanox to configure. You also need +to export the MICROWIN variable, setting it to the top-level of the +Microwindows hierarchy. Remember that MICROWIN needs to be defined +both at configuration time and at subsequent make time, so you +may find it convenient to put it in your .bash_profile or similar +file. + +Typically, various features in wxWindows will be switched off to +conserve space. The sample script below calls configure with typical +options for Nano-X. + +Before compiling wxNano-X, you will also need to edit your +Microwindows 'config' file to match the values hard-coded into +configure: + + ERASEMOVE=N (otherwise moving windows will look messy) + X11=Y + OPTIMIZE=N + DEBUG=Y + VERBOSE=Y + +Compile Microwindows by typing 'make' from within the Microwindows src +directory. + +Port notes +========== + +Nano-X has a different API from Xlib, although there +are many similarities. Instead of changing the wxWindows +code to reflect Nano-X conventions, a compatibility +layer has been added, in the form of these files: + +include/wx/x11/nanox/X11/Xlib.h ; Xlib compatibility +include/wx/x11/privx.h ; Useful macros +src/x11/nanox.c ; Xlib compatibility + +There is also an XtoNX.h compatibility header file +in Microwindows, which we augment with our Xlib.h +and nanox.c. + +Unfortunately it is not always possible, or economical, +to provide a complete Xlib emulation, so there are +still wxUSE_NANOX preprocessor directives in the code +for awkward cases. It may be possible to eliminate +some, but probably not all, of these in future. + +Port Status +=========== + +The port is in a very early stage: so far it links +and a window pops up, but that's about it. (The +wxX11 port using straight X11 is much more advanced.) + +Things to do: + +- implement some incomplete compatibility functions + in src/x11/nanox.c +- implement the colour database +- add mask capability, without which controls won't + display properly +- add further configuration options for disabling + code not normally needed in an embedded device +- optimization and code size reduction +- figuring out why libstdc++-libc is linked to + binaries -- is this done for any C++ program? + +Code Size +========= + +Allow about 2.5 MB for a shared wxWindows library, with the +dynamically linked minimal sample taking about 24KB. If statically +linked, minimal takes up just over 1MB when stripped. This 1MB +includes all of wxWindows used in the minimal sample including some of +the wxUniversal widgets. As application complexity increases, +the amount of wxWindows code pulled into statically linked +executables increases, but for large applications, the overhead +of wxWindows becomes less significant. + +Sample sizes: +------------- + +Statically-linked minimal (release): 1,024,272 bytes +Statically-linked widgets (release): 1,171,568 bytes + +Shared lib, stripped (debug): 2,486,716 bytes +Shared-lib minimal (debug), stripped: 23,896 bytes + +Shared lib, stripped (release): 2,315,5004 bytes +Shared-lib minimal (release), stripped: 23,896 bytes +(note: the -O flag was not passed to the minimal +makefile, for some reason) + +Strategies for reducing code size +--------------------------------- + +- Look at the .o files compiled in a build and check + for particularly large files, or files you wouldn't + expect to be there in an embedded build. +- Disable options for features that aren't necessary, + for example: image handlers (BMP, JPEG etc.), + wxVariant, wxWizard, wxListCtrl, src/univ/themes/gtk.c. +- Add options to configure.in/setup.h where necessary, + for finer-grained configuration. +- Rewrite functions or classes for alternative stripped-down + functionality. +- Remove unnecessary functionality or obsolete code from + wxWindows. +- Factor out wxWindows code to reduce repetition. +- Add inlining, remove unnecessary empty functions. +- Separate code out into individual files so that all of + a .o file doesn't get pulled in, just because an app + references something else in that file. For example, + advanced event types could be separated out. + This assumes that the linker isn't clever enough to + eliminate redundant functions. The fact that the + minimal and widgets samples are very close in size + is evidence that gcc is not doing a good job here. +- Experiment with compiler options. +- Commercially supported compilers may have better + code generation and/or linker optimisation than the + one you're currently using. + +Sample script for building wxNano-X +=================================== + +This script assumes that you will invoke it +from a build directory under the wxWindows +top level. So you might type: + +% cd wx2 +% mkdir nano-x +% cd nano-x +% makewxnanox + +If you need to restart compilation without +reconfiguring, just type 'make' from the same +directory. + +-----------------------------:x---------------------- + +#!/bin/sh +# makewxnanox + +export MICROWIN=/home/julians/microwindows/microwindows-0.89pre8 + +#DEBUGFLAGS="--enable-debug --enable-debug_cntxt --disable-optimise" +DEBUGFLAGS="--disable-debug --disable-debug_cntxt --enable-optimise" + +export CONFIGCMD="./configure $DEBUGFLAGS --enable-shared --enable-gui --with-x11 --enable-nanox --enable-log --with-threads --without-sockets --without-odbc --without-libjpeg --without-libtiff --without-png --without-regex --enable-no_exceptions --disable-protocols --disable-ipc --disable-dialupman --disable-apple_ieee --disable-fraction --disable-dynlib --disable-dynamicloader --disable-geometry --disable-fontmap --disable-std_iostreams --disable-filesystem --disable-fs_inet --disable-fs_zip --disable-zipstream --disable-snglinst --disable-mimetype --disable-url --disable-html --disable-constraints --disable-printarch --disable-mdi --disable-postscript --disable-PS-normalized --disable-afmfonts --disable-prologio --disable-resources --disable-dnd --disable-metafile --disable-treelayout --disable-grid --disable-propsheet --disable-splines --disable-joystick --disable-pcx --disable-iff --disable-pnm --disable-tabdialog --disable-newgrid" + +echo $CONFIGCMD +if [ ! -f ./configure ]; then + CONFIGCMD=".$CONFIGCMD" +fi + +echo Invoking $CONFIGCMD + +rm -f *.cache +$CONFIGCMD + +make + +-----------------------------:x----------------------