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- edid=[0|1] - Enable use of DDC + EDID to get monitor info 57 0: Disabled. 58 1: Enabled. If valid EDID info was read from the monitor the EDID info will 59 overrides the xres, yres and refresh from the video-mode env. variable. 60 Defaults to edid=1. 61 62For example to always use the hdmi connector, even if no cable is inserted, 63using edid info when available and otherwise initalizing it at 1024x768@60Hz, 64use: video-mode=sunxi:1024x768-24@60,monitor=dvi,hpd=0,edid=1 . 65