view README.Epoc @ 1176:dd2a8deeb26d

Date: Mon, 17 Oct 2005 20:09:03 -0400 From: Mark Schreiber <mark7@alumni.cmu.edu> To: ryan@clutteredmind.org Subject: [PATCH]SDL mprotect() crash fix (I'm going to throw this patch your way at the suggestion of #SDL -- for some reason, I had some difficulty sending it to the main list last time, and I go bonkers subscribing to send each email or patch...) Currently, when I run SDL applications as non-root using SDL_VIDEODRIVER=dga, the fbdev fallback mprotect()s read/write the proper size of mmapped /dev/fb0 (7.5MB), but on framebuffer release mprotect()s read-only the range by the entire size of my video memory (128MB), which causes a segfault: #0 0x002a9a27 in ?? () from /lib/libc.so.6 #1 0x04a63eb6 in SDL_XDGAUnmapFramebuffer (screen=3D0) at XF86DGA2.c:978 #2 0x04a63efc in SDL_XDGACloseFramebuffer (dpy=3D0x9d3f008, screen=3D0) at XF86DGA2.c:268 #3 0x04a68b57 in DGA_Available () at SDL_dgavideo.c:98 #4 0x04a53677 in SDL_VideoInit (driver_name=3D0xbfb0bfc7 "dga", flags=3D0) at SDL_video.c:180 #5 0x04a2613f in SDL_InitSubSystem (flags=3D32) at SDL.c:74 #6 0x04a2617c in SDL_Init (flags=3D32) at SDL.c:166 #7 0x08049722 in main (argc=3D1, argv=3D0x0) at testwin.c:32 This is SDL 1.2.8 on Fedora Core 4, radeon driver for a Radeon 9250, xorg-x11-6.8.2-37. I've attached a one-line patch against SDL CVS that updates the size of the framebuffer at framebuffer map time so that the mprotect() on unmap will be the same size. I'm not sure if this is the best approach (i.e. one might want to retain the original value), but it does make my SDL applications work without segfaulting. -- Best of luck, Mark Schreiber
author Ryan C. Gordon <icculus@icculus.org>
date Sat, 19 Nov 2005 18:57:00 +0000
parents 74a8f672f2f8
children
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==============================================================================
Using the Simple DirectMedia Layer with EPOC/SymbianOS 6.0
==============================================================================

==============================================================================
I.  Building the Simple DirectMedia Layer libraries:

  You can get Symbian SDK from: 
    http://www.symbian.com.
 
  First create "Epoc" directory under SDL main directory and unpack 
  EpocBuildFiles.zip in it.
   
  To build the librarys goto "epoc" directory and type:
    bldmake bldfiles
    abld makefile vc6 (for creating Microsoft Visual C++ makefiles)
    abld build wins udeb (building for wins emulator)
    abld build armi urel (building for real device)

==============================================================================
II. Building the Simple DirectMedia Layer programs:

  Building SDL test programs is easy once you have built the libraries:
    abld test build wins udeb
    abld test build armi urel

  Supported real screen resolutions
    320 x 200 x  8 bit
    320 x 200 x 12 bit
    640 x 200 x  8 bit
    640 x 200 x 12 bit
  Supported "emulated" screen resolutions 
    640 x 400 x  8 bit
    640 x 400 x 12 bit
    640 x 480 x  8 bit
    640 x 480 x 12 bit
  "Emulated" resolutions are implemented by by shrinking the screen vertically 
  i.e. only every second scanline is drawn. This is mainly ment to be used for 
  testing quick ports of programs. Using faked resolutions is a waste of memory 
  and cpu power!

==============================================================================
III. Running test programs

  Copy executable to the device and run it from the File manager.   The Esc 
  key quits demo programs. In Crystal, Exe programs do not appear in task list 
  nor in Extras :-(. Test programs are tested in Nokia 9210 Communicator.

  Special keys used in SDL:
    The Caps lock key enables or disables the virtual cursor. 
    Function keys are mapped as follows: 
    F1=chr+q, F2=chr+w,..., F8=chr+i, 
    F9=chr+a,..., F12=chr+d.

==============================================================================
IV.  Enjoy! :)

  If you have a project you'd like me to know about, or want to ask questions,
  go ahead and join the SDL developer's mailing list by sending e-mail to:

	sdl-request@libsdl.org

  and put "subscribe" into the subject of the message. Or alternatively you
  can use the web interface:

	http://www.libsdl.org/mailman/listinfo/sdl

  You can find more info about Epoc version of SDL from Hannu Viitala's 
  homepage
    http://www.mbnet.fi/~haviital
  
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