X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=doc%2FREADME.video;h=09a26b179368685b7a3a45a98a1d289aa91361a8;hb=HEAD;hp=34e199c2d29d67dd475ec2ea76ca36c2ca4a9691;hpb=53677ef18e25c97ac613349087c5cb33ae5a2741;p=u-boot diff --git a/doc/README.video b/doc/README.video index 34e199c2d2..09a26b1793 100644 --- a/doc/README.video +++ b/doc/README.video @@ -1,30 +1,77 @@ +SPDX-License-Identifier: GPL-2.0+ /* * (C) Copyright 2000 * Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it - * - * See file CREDITS for list of people who contributed to this - * project. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License as - * published by the Free Software Foundation; either version 2 of - * the License, or (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, - * MA 02111-1307 USA */ +"video-mode" environment variable +================================= + +The 'video-mode' environment variable can be used to enable and configure +some video drivers. The format matches the video= command-line option used +for Linux: + + video-mode=:x-@<,option=string> + + The video driver name, ignored by U-Boot + The X resolution (in pixels) to use. + The Y resolution (in pixels) to use. + The color depth (in bits) to use. + The frequency (in Hz) to use. + A comma-separated list of device-specific options + + U-Boot MPC8xx video controller driver -====================================== +===================================== The driver has been tested with the following configurations: - MPC823FADS with AD7176 on a PAL TV (YCbYCr) - arsenio@tin.it -- GENIETV with AD7177 on a PAL TV (YCbYCr) - arsenio@tin.it + +Example: video-mode=fslfb:1280x1024-32@60,monitor=dvi + + +U-Boot sunxi video controller driver +==================================== + +U-Boot supports hdmi and lcd output on Allwinner sunxi SoCs, lcd output +requires the CONFIG_VIDEO_LCD_MODE Kconfig value to be set. + +The sunxi U-Boot driver supports the following video-mode options: + +- monitor=[none|dvi|hdmi|lcd|vga|composite-*] - Select the video output to use + none: Disable video output. + dvi/hdmi: Selects output over the hdmi connector with dvi resp. hdmi output + format, if edid is used the format is automatically selected. + lcd: Selects video output to a LCD screen. + vga: Selects video output over the VGA connector. + composite-pal/composite-ntsc/composite-pal-m/composite-pal-nc: + Selects composite video output, note the specified resolution is + ignored with composite video output. + Defaults to monitor=dvi. + +- hpd=[0|1] - Enable use of the hdmi HotPlug Detect feature + 0: Disabled. Configure dvi/hdmi output even if no cable is detected + 1: Enabled. Fallback to the lcd / vga / none in that order (if available) + Defaults to hpd=1. + +- hpd_delay= - How long to wait for the hdmi HPD signal in milliseconds + When the monitor and the board power up at the same time, it may take some + time for the monitor to assert the HPD signal. This configures how long to + wait for the HPD signal before assuming no cable is connected. + Defaults to hpd_delay=500. + +- edid=[0|1] - Enable use of DDC + EDID to get monitor info + 0: Disabled. + 1: Enabled. If valid EDID info was read from the monitor the EDID info will + overrides the xres, yres and refresh from the video-mode env. variable. + Defaults to edid=1. + +- overscan_x/overscan_y= - Set x/y overscan value + This configures a black border on the left and right resp. top and bottom + to deal with overscanning displays. Defaults to overscan_x=32 and + overscan_y=20 for composite monitors, 0 for other monitors. + +For example to always use the hdmi connector, even if no cable is inserted, +using edid info when available and otherwise initalizing it at 1024x768@60Hz, +use: "setenv video-mode sunxi:1024x768-24@60,monitor=dvi,hpd=0,edid=1".