Exibir código-fonte para SiS 771/671 no Fedora 20

no lspci
 01:00.0 VGA compatible controller: Silicon Integrated Systems [SiS] 771/671 PCIE VGA Display Adapter (rev 10)

instalei os pacotes xorg
 sudo yum install xorg-x11-drivers

e em /etc/X11/xorg.conf
 Section "Device"
 Identifier "Generic Video Card"
 Boardname "sis"
 Busid "PCI:1:0:0"
 Driver "vesa"
 Screen 0
 Option "UseFBDev" "true"
 Option "DPMS"
 Option "NoAccel"
 Option "ShadowFB"
 Option "Turboqueue"
 Option "MaxXFBMem"
 EndSection
 
 Section "Monitor"
 Identifier "Configured Monitor"
 Vendorname "Generic LCD Display"
 Modelname "LCD Panel 1280x768"
 Horizsync 31.5-50.0
 Vertrefresh 56.0 - 65.0
 modeline "800x600@56" 36.0 800 824 896 1024 600 601 603 625 +hsync +vsync
 modeline "800x600@60" 40.0 800 840 968 1056 600 601 605 628 +hsync +vsync
 modeline "1024x768@60" 74.48 1280 1336 1472 1664 720 721 724 746 -hsync +vsync
 modeline "1280x768@60" 80.14 1280 1344 1480 1680 768 769 772 795 -hsync +vsync
 modeline "1280x720@60" 74.48 1280 1336 1472 1664 720 721 724 746 -hsync +vsync
 modeline "1280x800@60" 83.46 1280 1344 1480 1680 800 801 804 828 -hsync +vsync
 Gamma 1.0
 EndSection
 
 Section "Screen"
 Identifier "Default Screen"
 Monitor "Configured Monitor"
 Device "Configured Video Device"
 Defaultdepth 24
 SubSection "Display"
 Depth 24
 Virtual 1280 800
 Modes "1280x800@60" "1280x768@60" "1024x768@60" "800x600@60" "800x600@56"
 EndSubSection
 EndSection
 
 Section "Module"
 Disable "dri"
 Load "dbe" # Double-Buffering Extension
 Load "v4l" # Video for Linux
 Load "extmod"
 Load "type1"
 Load "freetype"
 Load "glx" # 3D layer
 Load "GLcore"
 Load "i2c"
 Load "bitmap"
 Load "ddc"
 Load "int10"
 Load "vbe"
 Load "speedo"
 Load "record"
 EndSection
 
 Section "DRI"
 Mode 0666
 EndSection


Referência
* http://marinheirodasgalaxias.blogspot.com.br/2013/01/driver-sis-no-fedora-17.html