0001 =========
0002 Tridentfb
0003 =========
0004
0005 Tridentfb is a framebuffer driver for some Trident chip based cards.
0006
0007 The following list of chips is thought to be supported although not all are
0008 tested:
0009
0010 those from the TGUI series 9440/96XX and with Cyber in their names
0011 those from the Image series and with Cyber in their names
0012 those with Blade in their names (Blade3D,CyberBlade...)
0013 the newer CyberBladeXP family
0014
0015 All families are accelerated. Only PCI/AGP based cards are supported,
0016 none of the older Tridents.
0017 The driver supports 8, 16 and 32 bits per pixel depths.
0018 The TGUI family requires a line length to be power of 2 if acceleration
0019 is enabled. This means that range of possible resolutions and bpp is
0020 limited comparing to the range if acceleration is disabled (see list
0021 of parameters below).
0022
0023 Known bugs:
0024
0025 1. The driver randomly locks up on 3DImage975 chip with acceleration
0026 enabled. The same happens in X11 (Xorg).
0027 2. The ramdac speeds require some more fine tuning. It is possible to
0028 switch resolution which the chip does not support at some depths for
0029 older chips.
0030
0031 How to use it?
0032 ==============
0033
0034 When booting you can pass the video parameter::
0035
0036 video=tridentfb
0037
0038 The parameters for tridentfb are concatenated with a ':' as in this example::
0039
0040 video=tridentfb:800x600-16@75,noaccel
0041
0042 The second level parameters that tridentfb understands are:
0043
0044 ======== =====================================================================
0045 noaccel turns off acceleration (when it doesn't work for your card)
0046
0047 fp use flat panel related stuff
0048 crt assume monitor is present instead of fp
0049
0050 center for flat panels and resolutions smaller than native size center the
0051 image, otherwise use
0052 stretch
0053
0054 memsize integer value in KB, use if your card's memory size is misdetected.
0055 look at the driver output to see what it says when initializing.
0056
0057 memdiff integer value in KB, should be nonzero if your card reports
0058 more memory than it actually has. For instance mine is 192K less than
0059 detection says in all three BIOS selectable situations 2M, 4M, 8M.
0060 Only use if your video memory is taken from main memory hence of
0061 configurable size. Otherwise use memsize.
0062 If in some modes which barely fit the memory you see garbage
0063 at the bottom this might help by not letting change to that mode
0064 anymore.
0065
0066 nativex the width in pixels of the flat panel.If you know it (usually 1024
0067 800 or 1280) and it is not what the driver seems to detect use it.
0068
0069 bpp bits per pixel (8,16 or 32)
0070 mode a mode name like 800x600-8@75 as described in
0071 Documentation/fb/modedb.rst
0072 ======== =====================================================================
0073
0074 Using insane values for the above parameters will probably result in driver
0075 misbehaviour so take care(for instance memsize=12345678 or memdiff=23784 or
0076 nativex=93)
0077
0078 Contact: jani@astechnix.ro
