From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luca Ceresoli Date: Mon, 18 Apr 2016 13:51:41 +0200 Subject: [Buildroot] [PATCH v2] raspberrypi, raspberrypi2: add a serial console In-Reply-To: <20160418133701.58f46491@free-electrons.com> References: <1460929546-11966-1-git-send-email-luca@lucaceresoli.net> <20160418133701.58f46491@free-electrons.com> Message-ID: <5714CA4D.1080502@lucaceresoli.net> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Dear Thomas, On 18/04/2016 13:37, Thomas Petazzoni wrote: > 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? Indeed a good suggestion! I'll have a look. Thanks, -- Luca