From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Date: Mon, 30 Mar 2015 09:06:10 +0200 Subject: [U-Boot] [PATCH] Document the format of the console environment variable In-Reply-To: <1427644521-13421-1-git-send-email-merker@debian.org> References: <20150329130518.GU32541@bill-the-cat> <1427644521-13421-1-git-send-email-merker@debian.org> Message-ID: <5518F5E2.4010803@redhat.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi, On 29-03-15 17:55, Karsten Merker wrote: > config_distro_bootcmd.h defines a common boot environment for > multiple platforms. Document the format of the console > environment variable to allow the use of generic boot scripts > on all supported platforms. > > Signed-off-by: Karsten Merker Maybe add something that distros are not encouraged to use this ? At least on Fedora we do not want to use it, as adding console=${console} to bootargs on systems with both video-output (e.g. hdmi out) and a serial port will cause boot messages to only be shown on the serial port as that is where the /dev/console then points. Whereas when using the devicetree chosen/stdout-path property (which can be set either by u-boot or in the dts with the kernel), the kernel will use both /dev/tty0 (so the hdmi out) and the serial port pointed to by chosen/stdout as console, showing boot messages on both, and systemd will still automatically spawn a getty on the serial console. Regards, Hans > --- > doc/README.distro | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/doc/README.distro b/doc/README.distro > index 0308a4c..3f7ee85 100644 > --- a/doc/README.distro > +++ b/doc/README.distro > @@ -201,6 +201,15 @@ variables be set. Default values for these variables are often hard-coded into > CONFIG_EXTRA_ENV_SETTINGS in the board's U-Boot configuration file, so that > the user doesn't have to configure them. > > +console: > + > + Mandatory. The default console device to be passed to the Linux kernel. > + > + The console device is specified in accordance with the guidelines > + described in Documentation/serial-console.txt in the Linux kernel sources. > + If the device is a serial port, the console variable must specify the > + console baudrate in addition to the console device, e.g. "ttyS0,115200". > + > fdt_addr: > > Mandatory for any system that provides the DTB in HW (e.g. ROM) and wishes >