1*4882a593Smuzhiyun/* 2*4882a593Smuzhiyun * (C) Copyright 2000 3*4882a593Smuzhiyun * Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it 4*4882a593Smuzhiyun * 5*4882a593Smuzhiyun * SPDX-License-Identifier: GPL-2.0+ 6*4882a593Smuzhiyun */ 7*4882a593Smuzhiyun 8*4882a593Smuzhiyun"video-mode" environment variable 9*4882a593Smuzhiyun================================= 10*4882a593Smuzhiyun 11*4882a593SmuzhiyunThe 'video-mode' environment variable can be used to enable and configure 12*4882a593Smuzhiyunsome video drivers. The format matches the video= command-line option used 13*4882a593Smuzhiyunfor Linux: 14*4882a593Smuzhiyun 15*4882a593Smuzhiyun video-mode=<driver>:<xres>x<yres>-<depth>@<freq><,option=string> 16*4882a593Smuzhiyun 17*4882a593Smuzhiyun <driver> The video driver name, ignored by U-Boot 18*4882a593Smuzhiyun <xres> The X resolution (in pixels) to use. 19*4882a593Smuzhiyun <yres> The Y resolution (in pixels) to use. 20*4882a593Smuzhiyun <depth> The color depth (in bits) to use. 21*4882a593Smuzhiyun <freq> The frequency (in Hz) to use. 22*4882a593Smuzhiyun <options> A comma-separated list of device-specific options 23*4882a593Smuzhiyun 24*4882a593Smuzhiyun 25*4882a593SmuzhiyunU-Boot MPC8xx video controller driver 26*4882a593Smuzhiyun===================================== 27*4882a593Smuzhiyun 28*4882a593SmuzhiyunThe driver has been tested with the following configurations: 29*4882a593Smuzhiyun 30*4882a593Smuzhiyun- MPC823FADS with AD7176 on a PAL TV (YCbYCr) - arsenio@tin.it 31*4882a593Smuzhiyun 32*4882a593SmuzhiyunExample: video-mode=fslfb:1280x1024-32@60,monitor=dvi 33*4882a593Smuzhiyun 34*4882a593Smuzhiyun 35*4882a593SmuzhiyunU-Boot sunxi video controller driver 36*4882a593Smuzhiyun==================================== 37*4882a593Smuzhiyun 38*4882a593SmuzhiyunU-Boot supports hdmi and lcd output on Allwinner sunxi SoCs, lcd output 39*4882a593Smuzhiyunrequires the CONFIG_VIDEO_LCD_MODE Kconfig value to be set. 40*4882a593Smuzhiyun 41*4882a593SmuzhiyunThe sunxi U-Boot driver supports the following video-mode options: 42*4882a593Smuzhiyun 43*4882a593Smuzhiyun- monitor=[none|dvi|hdmi|lcd|vga|composite-*] - Select the video output to use 44*4882a593Smuzhiyun none: Disable video output. 45*4882a593Smuzhiyun dvi/hdmi: Selects output over the hdmi connector with dvi resp. hdmi output 46*4882a593Smuzhiyun format, if edid is used the format is automatically selected. 47*4882a593Smuzhiyun lcd: Selects video output to a LCD screen. 48*4882a593Smuzhiyun vga: Selects video output over the VGA connector. 49*4882a593Smuzhiyun composite-pal/composite-ntsc/composite-pal-m/composite-pal-nc: 50*4882a593Smuzhiyun Selects composite video output, note the specified resolution is 51*4882a593Smuzhiyun ignored with composite video output. 52*4882a593Smuzhiyun Defaults to monitor=dvi. 53*4882a593Smuzhiyun 54*4882a593Smuzhiyun- hpd=[0|1] - Enable use of the hdmi HotPlug Detect feature 55*4882a593Smuzhiyun 0: Disabled. Configure dvi/hdmi output even if no cable is detected 56*4882a593Smuzhiyun 1: Enabled. Fallback to the lcd / vga / none in that order (if available) 57*4882a593Smuzhiyun Defaults to hpd=1. 58*4882a593Smuzhiyun 59*4882a593Smuzhiyun- hpd_delay=<int> - How long to wait for the hdmi HPD signal in milliseconds 60*4882a593Smuzhiyun When the monitor and the board power up at the same time, it may take some 61*4882a593Smuzhiyun time for the monitor to assert the HPD signal. This configures how long to 62*4882a593Smuzhiyun wait for the HPD signal before assuming no cable is connected. 63*4882a593Smuzhiyun Defaults to hpd_delay=500. 64*4882a593Smuzhiyun 65*4882a593Smuzhiyun- edid=[0|1] - Enable use of DDC + EDID to get monitor info 66*4882a593Smuzhiyun 0: Disabled. 67*4882a593Smuzhiyun 1: Enabled. If valid EDID info was read from the monitor the EDID info will 68*4882a593Smuzhiyun overrides the xres, yres and refresh from the video-mode env. variable. 69*4882a593Smuzhiyun Defaults to edid=1. 70*4882a593Smuzhiyun 71*4882a593Smuzhiyun- overscan_x/overscan_y=<int> - Set x/y overscan value 72*4882a593Smuzhiyun This configures a black border on the left and right resp. top and bottom 73*4882a593Smuzhiyun to deal with overscanning displays. Defaults to overscan_x=32 and 74*4882a593Smuzhiyun overscan_y=20 for composite monitors, 0 for other monitors. 75*4882a593Smuzhiyun 76*4882a593SmuzhiyunFor example to always use the hdmi connector, even if no cable is inserted, 77*4882a593Smuzhiyunusing edid info when available and otherwise initalizing it at 1024x768@60Hz, 78*4882a593Smuzhiyunuse: "setenv video-mode sunxi:1024x768-24@60,monitor=dvi,hpd=0,edid=1". 79