| 1 | Nano-X port |
| 2 | =========== |
| 3 | |
| 4 | What is it? |
| 5 | =========== |
| 6 | |
| 7 | The Nano-X port is based on the wxX11 code, and therefore shares |
| 8 | almost all of wxX11's code, including the use of the wxUniversal |
| 9 | widget set. Nano-X is the X-like API of the overall Microwindows |
| 10 | project, which also has a WIN32 API. |
| 11 | |
| 12 | The Microwindows web site is at |
| 13 | |
| 14 | http://microwindows.org/ |
| 15 | |
| 16 | Nano-X is intended to work on devices with very small amounts |
| 17 | of memory. wxWidgets is quite a large library, so if your |
| 18 | memory is measured in KB instead of MB you will need to use |
| 19 | an alternative library, such as FLTK. However, with memory |
| 20 | capacity increasing all the time, wxWidgets could become |
| 21 | an appropriate embedded GUI solution for many projects. |
| 22 | Also, it's possible to think of ways to cut wxWidgets |
| 23 | further down to size, such as disabling advanced controls |
| 24 | or rewriting utility functions. See the section on code size |
| 25 | below. |
| 26 | |
| 27 | An alternative to using Nano-X is to use the standard |
| 28 | wxX11 port with Tiny-X, which (as I understand it) |
| 29 | maintains the Xlib API while being sufficiently cut |
| 30 | down to run on small devices, such as the iPAQ. |
| 31 | The Familiar Linux Distribution contains Tiny-X. See: |
| 32 | |
| 33 | http://handhelds.org/mailman/listinfo/familiar |
| 34 | |
| 35 | Building wxNano-X |
| 36 | ================= |
| 37 | |
| 38 | Building is as per the instructions for wxX11 (see readme.txt, |
| 39 | install.txt) but passing --enable-nanox to configure. You also need |
| 40 | to export the MICROWIN variable, setting it to the top-level of the |
| 41 | Microwindows hierarchy. Remember that MICROWIN needs to be defined |
| 42 | both at configuration time and at subsequent make time, so you |
| 43 | may find it convenient to put it in your .bash_profile or similar |
| 44 | file. |
| 45 | |
| 46 | Typically, various features in wxWidgets will be switched off to |
| 47 | conserve space. The sample script below calls configure with typical |
| 48 | options for Nano-X. |
| 49 | |
| 50 | Before compiling wxNano-X, you will also need to edit your |
| 51 | Microwindows 'config' file to match the values hard-coded into |
| 52 | configure: |
| 53 | |
| 54 | ERASEMOVE=N (otherwise moving windows will look messy) |
| 55 | X11=Y |
| 56 | OPTIMIZE=N |
| 57 | DEBUG=Y |
| 58 | VERBOSE=Y |
| 59 | |
| 60 | Compile Microwindows by typing 'make' from within the Microwindows src |
| 61 | directory. |
| 62 | |
| 63 | Port notes |
| 64 | ========== |
| 65 | |
| 66 | Nano-X has a different API from Xlib, although there |
| 67 | are many similarities. Instead of changing the wxWidgets |
| 68 | code to reflect Nano-X conventions, a compatibility |
| 69 | layer has been added, in the form of these files: |
| 70 | |
| 71 | include/wx/x11/nanox/X11/Xlib.h ; Xlib compatibility |
| 72 | include/wx/x11/privx.h ; Useful macros |
| 73 | src/x11/nanox.c ; Xlib compatibility |
| 74 | |
| 75 | There is also an XtoNX.h compatibility header file |
| 76 | in Microwindows, which we augment with our Xlib.h |
| 77 | and nanox.c. |
| 78 | |
| 79 | Unfortunately it is not always possible, or economical, |
| 80 | to provide a complete Xlib emulation, so there are |
| 81 | still wxUSE_NANOX preprocessor directives in the code |
| 82 | for awkward cases. It may be possible to eliminate |
| 83 | some, but probably not all, of these in future. |
| 84 | |
| 85 | Port Status |
| 86 | =========== |
| 87 | |
| 88 | The port is in a very early stage: so far it links |
| 89 | and a window pops up, but that's about it. (The |
| 90 | wxX11 port using straight X11 is much more advanced.) |
| 91 | |
| 92 | Things to do: |
| 93 | |
| 94 | - implement some incomplete compatibility functions |
| 95 | in src/x11/nanox.c |
| 96 | - implement the colour database |
| 97 | - add mask capability, without which controls won't |
| 98 | display properly |
| 99 | - add further configuration options for disabling |
| 100 | code not normally needed in an embedded device |
| 101 | - optimization and code size reduction |
| 102 | - figuring out why libstdc++-libc is linked to |
| 103 | binaries -- is this done for any C++ program? |
| 104 | |
| 105 | Code Size |
| 106 | ========= |
| 107 | |
| 108 | Allow about 2.5 MB for a shared wxWidgets library, with the |
| 109 | dynamically linked minimal sample taking about 24KB. If statically |
| 110 | linked, minimal takes up just over 1MB when stripped. This 1MB |
| 111 | includes all of wxWidgets used in the minimal sample including some of |
| 112 | the wxUniversal widgets. As application complexity increases, |
| 113 | the amount of wxWidgets code pulled into statically linked |
| 114 | executables increases, but for large applications, the overhead |
| 115 | of wxWidgets becomes less significant. |
| 116 | |
| 117 | Sample sizes: |
| 118 | ------------- |
| 119 | |
| 120 | Statically-linked minimal (release): 1,024,272 bytes |
| 121 | Statically-linked widgets (release): 1,171,568 bytes |
| 122 | |
| 123 | Shared lib, stripped (debug): 2,486,716 bytes |
| 124 | Shared-lib minimal (debug), stripped: 23,896 bytes |
| 125 | |
| 126 | Shared lib, stripped (release): 2,315,5004 bytes |
| 127 | Shared-lib minimal (release), stripped: 23,896 bytes |
| 128 | (note: the -O flag was not passed to the minimal |
| 129 | makefile, for some reason) |
| 130 | |
| 131 | Strategies for reducing code size |
| 132 | --------------------------------- |
| 133 | |
| 134 | - Look at the .o files compiled in a build and check |
| 135 | for particularly large files, or files you wouldn't |
| 136 | expect to be there in an embedded build. |
| 137 | - Disable options for features that aren't necessary, |
| 138 | for example: image handlers (BMP, JPEG etc.), |
| 139 | wxVariant, wxWizard, wxListCtrl, src/univ/themes/gtk.c. |
| 140 | - Add options to configure.in/setup.h where necessary, |
| 141 | for finer-grained configuration. |
| 142 | - Rewrite functions or classes for alternative stripped-down |
| 143 | functionality. |
| 144 | - Remove unnecessary functionality or obsolete code from |
| 145 | wxWidgets. |
| 146 | - Factor out wxWidgets code to reduce repetition. |
| 147 | - Add inlining, remove unnecessary empty functions. |
| 148 | - Separate code out into individual files so that all of |
| 149 | a .o file doesn't get pulled in, just because an app |
| 150 | references something else in that file. For example, |
| 151 | advanced event types could be separated out. |
| 152 | This assumes that the linker isn't clever enough to |
| 153 | eliminate redundant functions. The fact that the |
| 154 | minimal and widgets samples are very close in size |
| 155 | is evidence that gcc is not doing a good job here. |
| 156 | - Experiment with compiler options. |
| 157 | - Commercially supported compilers may have better |
| 158 | code generation and/or linker optimisation than the |
| 159 | one you're currently using. |
| 160 | |
| 161 | Sample script for building wxNano-X |
| 162 | =================================== |
| 163 | |
| 164 | This script assumes that you will invoke it |
| 165 | from a build directory under the wxWidgets |
| 166 | top level. So you might type: |
| 167 | |
| 168 | % cd wx2 |
| 169 | % mkdir nano-x |
| 170 | % cd nano-x |
| 171 | % makewxnanox |
| 172 | |
| 173 | If you need to restart compilation without |
| 174 | reconfiguring, just type 'make' from the same |
| 175 | directory. |
| 176 | |
| 177 | -----------------------------:x---------------------- |
| 178 | |
| 179 | #!/bin/sh |
| 180 | # makewxnanox |
| 181 | |
| 182 | export MICROWIN=/home/julians/microwindows/microwindows-0.89pre8 |
| 183 | |
| 184 | #DEBUGFLAGS="--enable-debug --enable-debug_cntxt --disable-optimise" |
| 185 | DEBUGFLAGS="--disable-debug --disable-debug_cntxt --enable-optimise" |
| 186 | |
| 187 | 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" |
| 188 | |
| 189 | echo $CONFIGCMD |
| 190 | if [ ! -f ./configure ]; then |
| 191 | CONFIGCMD=".$CONFIGCMD" |
| 192 | fi |
| 193 | |
| 194 | echo Invoking $CONFIGCMD |
| 195 | |
| 196 | rm -f *.cache |
| 197 | $CONFIGCMD |
| 198 | |
| 199 | make |
| 200 | |
| 201 | -----------------------------:x---------------------- |