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