From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Date: Mon, 18 Apr 2016 13:37:01 +0200 Subject: [Buildroot] [PATCH v2] raspberrypi, raspberrypi2: add a serial console In-Reply-To: <1460929546-11966-1-git-send-email-luca@lucaceresoli.net> References: <1460929546-11966-1-git-send-email-luca@lucaceresoli.net> Message-ID: <20160418133701.58f46491@free-electrons.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Hello, On Sun, 17 Apr 2016 23:45:46 +0200, Luca Ceresoli wrote: > The current Buildroot defconfigs for Raspberry Pi and Raspberry Pi 2 > instantiate a console on tty1, which appears on HDMI. Add a console on > the serial port (ttyAMA0) to be more consistent with other defconfigs > and provide a better out-of-the-box experience to users used to have a > serial console from Buildroot defconfigs. > > This requires three changes: > 1. have two 'console=' entries in the kernel command line: tty1, > then ttyAMA0; > 2. change BR2_TARGET_GENERIC_GETTY_PORT to "console", so it starts > a getty on the last console= passed to the kernel, ttyAMA0; > 3. add a new getty on tty1 to the generated inittab. > > Step 2 is actually obtained by removing BR2_TARGET_GENERIC_GETTY_PORT > entirely from the defconfigs, since "console" is the default value. > > Step 3 requires a post-build script since the Buildroot makefiles can > configure only one console. > > Note: instead of simply adding a new getty on ttyAMA0 (which would > work) this patch actually changes BR2_TARGET_GENERIC_GETTY_PORT to > instantiate a console on UART, then adds back tty1 via > post-build.sh. This is done only to avoid the "GENERIC_SERIAL" comment > where we instantiate an HDMI console, then instantiate a really-serial > console on another line. > > The result is these two inittab lines: > > console::respawn:/sbin/getty -L console 0 vt100 # GENERIC_SERIAL > tty1::respawn:/sbin/getty -L tty1 0 vt100 # HDMI console > > Cc: Yann E. MORIN > Cc: Arnout Vandecappelle > Signed-off-by: Luca Ceresoli > > --- Applied to master, thanks. Maybe this calls for an update of the RaspberryPi readme.txt file, to explicitly indicate that a getty will be running on both the HDMI/composite output *and* the serial port? Thanks! Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com