+SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2000
* Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it
- *
- * SPDX-License-Identifier: GPL-2.0+
*/
-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
-
"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
<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".
+
+
+TrueType fonts
+--------------
+
+U-Boot supports the use of antialiased TrueType fonts on some platforms. This
+has been tested in x86, ARMv7 and sandbox.
+
+To enable this, select CONFIG_CONSOLE_TRUETYPE. You can choose between several
+fonts, with CONSOLE_TRUETYPE_NIMBUS being the default.
+
+TrueType support requires floating point at present. On ARMv7 platforms you
+need to disable use of the private libgcc. You can do this by disabling
+CONFIG_USE_PRIVATE_LIBGCC. See chromebook_jerry for an example. Note that this
+increases U-Boot's size by about 70KB at present.
+
+On ARM you should also make sure your toolchain supports hardfp. This is
+normally given in the name of your toolchain, e.g. arm-linux-gnueabihf (hf
+means hardware floating point). You can also run gcc with -v to see if it has
+this option.
projects / oweals / u-boot.git / blobdiff