X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=doc%2FREADME.video;h=ced35bd2db55dcb3781dd333e909395334e51b59;hb=1e374089bdfb4fd41a34204b53474180e0be0125;hp=dadbfcd2fdc8934d8f09a7d1b17c66dc9863a06d;hpb=b8a49bdaaad386d09a47d450d00c4e64f1f354a3;p=oweals%2Fu-boot.git diff --git a/doc/README.video b/doc/README.video index dadbfcd2fd..ced35bd2db 100644 --- a/doc/README.video +++ b/doc/README.video @@ -1,19 +1,11 @@ +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 @@ -28,4 +20,78 @@ for Linux: 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 + 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". + + +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.