mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-11 05:42:58 +00:00
a187559e3d
Correct spelling of "U-Boot" shall be used in all written text (documentation, comments in source files etc.). Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Heiko Schocher <hs@denx.de> Reviewed-by: Simon Glass <sjg@chromium.org> Reviewed-by: Minkyu Kang <mk7.kang@samsung.com>
78 lines
3.1 KiB
Text
78 lines
3.1 KiB
Text
/*
|
|
* (C) Copyright 2000
|
|
* Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
"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=<driver>:<xres>x<yres>-<depth>@<freq><,option=string>
|
|
|
|
<driver> The video driver name, ignored by U-Boot
|
|
<xres> The X resolution (in pixels) to use.
|
|
<yres> The Y resolution (in pixels) to use.
|
|
<depth> The color depth (in bits) to use.
|
|
<freq> The frequency (in Hz) to use.
|
|
<options> 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
|
|
|
|
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=<int> - 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=<int> - 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".
|