Documentation/fb/modedb.rst

2 modedb default video mode support
6 Currently all frame buffer device drivers have their own video mode databases,
9   - one routine to probe for video modes, which can be used by all frame buffer
11   - one generic video mode database with a fair amount of standard videomodes
13   - the possibility to supply your own mode database for graphics hardware that
14     needs non-standard modes, like amifb and Mac frame buffer drivers (which
17 When a frame buffer device receives a video= option it doesn't know, it should
18 consider that to be a video mode option. If no frame buffer device is specified
19 in a video= option, fbmem considers that to be a global video mode option.
21 Valid mode specifiers (mode_option argument)::
23     <xres>x<yres>[M][R][-<bpp>][@<refresh>][i][m][eDd]
24     <name>[-<bpp>][@<refresh>]
31 VESA(TM) Coordinated Video Timings instead of looking up the mode from a table.
33 If 'i' is specified, calculate for an interlaced mode.  And if 'm' is
37        Sample usage: 1024x768M@60m - CVT timing with margins
44 signals (e.g. HDMI and DVI-I). For other outputs it behaves like 'e'. If 'd'
48 To force the VGA output to be enabled and drive a specific mode say::
50     video=VGA-1:1280x1024@60me
54     video=LVDS-1:d video=HDMI-1:D
56 Options can also be passed after the mode, using commas as separator.
58        Sample usage: 720x480,rotate=180 - 720x480 mode, rotated by 180 degrees
62   - margin_top, margin_bottom, margin_left, margin_right (integer):
64   - reflect_x (boolean): Perform an axial symmetry on the X axis
65   - reflect_y (boolean): Perform an axial symmetry on the Y axis
66   - rotate (integer): Rotate the initial framebuffer by x
68   - panel_orientation, one of "normal", "upside_down", "left_side_up", or
73 -----------------------------------------------------------------------------
75 What is the VESA(TM) Coordinated Video Timings (CVT)?
88 This is the third standard approved by VESA(TM) concerning video timings.  The
89 first was the Discrete Video Timings (DVT) which is  a collection of
90 pre-defined modes approved by VESA(TM).  The second is the Generalized Timing
105 to the global mode database whenever a new mode is released by display
109 determined from its EDID. The version 1.3 of the EDID has extra 128-byte
115     <pix>M<a>[-R]
119 	   a   = aspect ratio (3 - 4:3; 4 - 5:4; 9 - 15:9, 16:9; A - 16:10)
120 	  -R   = reduced blanking
122 	  example:  .48M3-R - 800x600 with reduced blanking
126       - aspect ratio can only be one of the above values
127       - acceptable refresh rates are 50, 60, 70 or 85 Hz only
128       - if reduced blanking, the refresh rate must be at 60Hz
133 -----------------------------------------------------------------------------
135 To find a suitable video mode, you just call::
143 with db/dbsize your non-standard video mode database, or NULL to use the
144 standard video mode database.
146 fb_find_mode() first tries the specified video mode (or any mode that matches,
148 fails, the default mode is tried. If that fails, it walks over all modes.
150 To specify a video mode at bootup, use the following boot options::
152     video=<driver>:<xres>x<yres>[-<bpp>][@refresh]
155 found in drivers/video/fbdev/core/modedb.c.  Check your driver's documentation.
161     amifb	- Amiga chipset frame buffer
162     aty128fb	- ATI Rage128 / Pro frame buffer
163     atyfb	- ATI Mach64 frame buffer
164     pm2fb	- Permedia 2/2V frame buffer
165     pm3fb	- Permedia 3 frame buffer
166     sstfb	- Voodoo 1/2 (SST1) chipset frame buffer
167     tdfxfb	- 3D Fx frame buffer
168     tridentfb	- Trident (Cyber)blade chipset frame buffer
169     vt8623fb	- VIA 8623 frame buffer