mirror of https://gitee.com/openkylin/linux.git
79 lines
2.8 KiB
ReStructuredText
79 lines
2.8 KiB
ReStructuredText
=========
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Tridentfb
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=========
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Tridentfb is a framebuffer driver for some Trident chip based cards.
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The following list of chips is thought to be supported although not all are
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tested:
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those from the TGUI series 9440/96XX and with Cyber in their names
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those from the Image series and with Cyber in their names
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those with Blade in their names (Blade3D,CyberBlade...)
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the newer CyberBladeXP family
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All families are accelerated. Only PCI/AGP based cards are supported,
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none of the older Tridents.
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The driver supports 8, 16 and 32 bits per pixel depths.
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The TGUI family requires a line length to be power of 2 if acceleration
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is enabled. This means that range of possible resolutions and bpp is
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limited comparing to the range if acceleration is disabled (see list
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of parameters below).
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Known bugs:
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1. The driver randomly locks up on 3DImage975 chip with acceleration
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enabled. The same happens in X11 (Xorg).
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2. The ramdac speeds require some more fine tuning. It is possible to
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switch resolution which the chip does not support at some depths for
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older chips.
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How to use it?
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==============
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When booting you can pass the video parameter::
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video=tridentfb
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The parameters for tridentfb are concatenated with a ':' as in this example::
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video=tridentfb:800x600-16@75,noaccel
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The second level parameters that tridentfb understands are:
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======== =====================================================================
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noaccel turns off acceleration (when it doesn't work for your card)
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fp use flat panel related stuff
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crt assume monitor is present instead of fp
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center for flat panels and resolutions smaller than native size center the
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image, otherwise use
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stretch
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memsize integer value in KB, use if your card's memory size is misdetected.
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look at the driver output to see what it says when initializing.
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memdiff integer value in KB, should be nonzero if your card reports
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more memory than it actually has. For instance mine is 192K less than
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detection says in all three BIOS selectable situations 2M, 4M, 8M.
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Only use if your video memory is taken from main memory hence of
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configurable size. Otherwise use memsize.
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If in some modes which barely fit the memory you see garbage
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at the bottom this might help by not letting change to that mode
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anymore.
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nativex the width in pixels of the flat panel.If you know it (usually 1024
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800 or 1280) and it is not what the driver seems to detect use it.
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bpp bits per pixel (8,16 or 32)
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mode a mode name like 800x600-8@75 as described in
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Documentation/fb/modedb.rst
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======== =====================================================================
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Using insane values for the above parameters will probably result in driver
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misbehaviour so take care(for instance memsize=12345678 or memdiff=23784 or
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nativex=93)
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Contact: jani@astechnix.ro
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