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