mirror of
https://github.com/u-boot/u-boot.git
synced 2024-11-26 05:34:30 +08:00
7fad8a9802
In some extreme cases it may be necessary to wait 1.5 seconds or more for a hpd signal to show up (and be able to read edid info), but we do not want to penalize all headless boots with an extra second boot delay, so add a hpd_delay parameter which can be set through the video-mode env. variable. While at it raise the default from 300ms to 500ms as 300 may very well be too low in many cases. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Ian Campbell <ijc@hellion.org.uk>
71 lines
2.6 KiB
Plaintext
71 lines
2.6 KiB
Plaintext
/*
|
|
* (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] - 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 bideo output over the VGA connector.
|
|
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.
|
|
|
|
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".
|