view README.NanoX @ 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 26dafefeebb2
children
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  =================================================================
  Patch version 0.9 of SDL(Simple DirectMedia Layer) for Nano-X API
  =================================================================
  
  Authors: Hsieh-Fu Tsai, clare@setabox.com
           Greg Haerr, greg@censoft.com

  This patch is against SDL version 1.2.4.
  It enhances previous patch 0.8 by providing direct framebuffer
  access as well as dynamic hardware pixel type support, not
  requiring a compile-time option setting for different framebuffer
  modes.
  Tested against Microwindows version 0.89pre9.

  Older Microwindows versions
  ===========================
  If running on a version older than Microwindows 0.89pre9,
  the following items might need to be patched in Microwindows.

  1. Patch src/nanox/client.c::GrClose()
  It fixes the client side GrClose(). In the original version, 
  GrOpen() can only be called once. When the GrOpen() is called at 
  the second time, the program will terminate. In order to prevent
  this situation, we need to insert "nxSocket = -1" after 
  "close(nxSocket)" in GrClose(). If you do not have this problem,
  you may skip this step. 

  2. Patch src/nanox/clientfb.c to return absolute x,y coordinates
  when using GrGetWindowFBInfo().  Copy the version 0.89pre9
  of src/nanox/clientfb.c to your system, or configure
  using --disable-nanox-direct-fb.

  =============
  Quick Install 
  =============

  1. ./configure --disable-video-x11 --disable-video-fbcon \ 
       --enable-video-nanox \ 
       --with-nanox-pixel-type=[rgb/0888/888/565/555/332/pal] 
  2. make clean 
  3. make 
  4. make install (as root) 

  ============
  Nitty-gritty 
  ============

  --enable-nanox-direct-fb       Use direct framebuffer access
  --enable-nanox-debug           Show debug messages 
  --enable-nanox-share-memory    Use shared-memory to speed up 

  When running multi-threaded applications using SDL, such
  as SMPEG, set THREADSAFE=Y in Microwindows' config file,
  to enable GrXXX() system call critical section support.

  =============================================
  Some programs can be used to test this patch. 
  =============================================

  1. http://www.cs.berkeley.edu/~weimer/atris (a tetris-like game) 
  2. http://www.libsdl.org/projects/newvox/
  3. http://www.libsdl.org/projects/xflame/
  4. http://www.libsdl.org/projects/optimum/ 
  5. http://www.gnugeneration.com/software/loop/ 
  6: http://www.lokigames.com/development/smpeg.php3 (SMPEG version 0.4.4)

  =========
  Todo List 
  =========

  1. Create hardware surface
  2. Create YUVOverlay on hardware
  3. Use OpenGL
  4. Gamma correction
  5. Hide/Change mouse pointer
  6. Better window movement control with direct fb access
  7. Palette handling in 8bpp could be improved

  =====================
  Supporting Institutes
  =====================
  
  Many thanks to go to Setabox Co., Ltd. and CML (Communication and
  Multimedia Laboratory, http://www.cmlab.csie.ntu.edu.tw/) in the 
  Department of Computer Science and Information Engineering of 
  National Taiwan University for supporting this porting project.
  
  Century Embedded Technologies (http://embedded.censoft.com)
  for this patch.

  ===================
  Contact Information
  ===================

  Welcome to give me any suggestion and to report bugs.
  My e-mail address : clare@setabox.com or niky@cmlab.csie.ntu.edu.tw
                      or greg@censoft.com