1============================================================================== 2Using the Simple DirectMedia Layer with OpenBSD/wscons 3============================================================================== 4 5The wscons SDL driver can be used to run SDL programs on OpenBSD 6without running X. So far, the driver only runs on the Sharp Zaurus, 7but the driver is written to be easily extended for other machines. 8The main missing pieces are blitting routines for anything but 16 bit 9displays, and keycode maps for other keyboards. Also, there is no 10support for hardware palettes. 11 12There is currently no mouse support. 13 14To compile SDL with support for wscons, use the 15"--enable-video-wscons" option when running configure. I used the 16following command line: 17 18./configure --disable-oss --disable-ltdl --enable-pthread-sem \ 19 --disable-esd --disable-arts --disable-video-aalib \ 20 --enable-openbsdaudio --enable-video-wscons \ 21 --prefix=/usr/local --sysconfdir=/etc 22 23 24Setting the console device to use 25================================= 26 27When starting an SDL program on a wscons console, the driver uses the 28current virtual terminal (usually /dev/ttyC0). To force the driver to 29use a specific terminal device, set the environment variable 30SDL_WSCONSDEV: 31 32bash$ SDL_WSCONSDEV=/dev/ttyC1 ./some-sdl-program 33 34This is especially useful when starting an SDL program from a remote 35login prompt (which is great for development). If you do this, and 36want to use keyboard input, you should avoid having some other program 37reading from the used virtual console (i.e., do not have a getty 38running). 39 40 41Rotating the display 42==================== 43 44The display can be rotated by the wscons SDL driver. This is useful 45for the Sharp Zaurus, since the display hardware is wired so that it 46is correctly rotated only when the display is folded into "PDA mode." 47When using the Zaurus in "normal," or "keyboard" mode, the hardware 48screen is rotated 90 degrees anti-clockwise. 49 50To let the wscons SDL driver rotate the screen, set the environment 51variable SDL_VIDEO_WSCONS_ROTATION to "CW", "CCW", or "UD", for 52clockwise, counter clockwise, and upside-down rotation respectively. 53"CW" makes the screen appear correct on a Sharp Zaurus SL-C3100. 54 55When using rotation in the driver, a "shadow" frame buffer is used to 56hold the intermediary display, before blitting it to the actual 57hardware frame buffer. This slows down performance a bit. 58 59For completeness, the rotation "NONE" can be specified to use a shadow 60frame buffer without actually rotating. Unsetting 61SDL_VIDEO_WSCONS_ROTATION, or setting it to '' turns off the shadow 62frame buffer for maximum performance. 63 64 65Running MAME 66============ 67 68Since my main motivation for writing the driver was playing MAME on 69the Zaurus, I'll give a few hints: 70 71XMame compiles just fine under OpenBSD. 72 73I'm not sure this is strictly necessary, but set 74 75MY_CPU = arm 76 77in makefile.unix, and 78 79CFLAGS.arm = -DLSB_FIRST -DALIGN_INTS -DALIGN_SHORTS 80 81in src/unix/unix.max 82 83to be sure. 84 85The latest XMame (0.101 at this writing) is a very large program. 86Either tinker with the make files to compile a version without support 87for all drivers, or, get an older version of XMame. My recommendation 88would be 0.37b16. 89 90When running MAME, DO NOT SET SDL_VIDEO_WSCONS_ROTATION! Performace 91is MUCH better without this, and it is COMPLETELY UNNECESSARY, since 92MAME can rotate the picture itself while drawing, and does so MUCH 93FASTER. 94 95Use the Xmame command line option "-ror" to rotate the picture to the 96right. 97 98 99Acknowledgments 100=============== 101 102I studied the wsfb driver for XFree86/Xorg quite a bit before writing 103this, so there ought to be some similarities. 104 105 106-- 107Staffan Ulfberg <staffan@ulfberg.se> 108