From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sascha Hauer Subject: Re: [PATCH] of: support passing console options with stdout-path Date: Tue, 25 Nov 2014 07:49:58 +0100 Message-ID: <20141125064958.GK30369@pengutronix.de> References: <1416867838-18652-1-git-send-email-leif.lindholm@linaro.org> <20141124230016.GP20238@lunn.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20141124230016.GP20238-g2DYL2Zd6BY@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Andrew Lunn Cc: Leif Lindholm , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, plagnioj-sclMFOaUSTBWk0Htik3J/w@public.gmane.org, ijc-8fiUuRrzOP0dnm+yROfE0A@public.gmane.org List-Id: devicetree@vger.kernel.org On Tue, Nov 25, 2014 at 12:00:16AM +0100, Andrew Lunn wrote: > On Mon, Nov 24, 2014 at 10:23:58PM +0000, Leif Lindholm wrote: > > Support specifying console options (like with console=ttyXN,) > > by appending them to the stdout-path property after a separating ':'. > > > > Example: > > stdout-path = "uart0:115200"; > > > > This patch also modifies of_find_node_by_path() to match only the > > portion of the path before a ':'. > > Hi Leif > > These appears to somewhat conform to ePAPR, which says: > > A string that specifies the full path to the node representing > the device to be used for boot console output. If the character > ":" is present in the value it terminates the path. > > So you can put any random junk after the :. However, are we going to > have backward/forward compatibility problems, and problems with > bootloaders? The current kernel code does not look for the :. So a new > DT blob on an old kernel will not work so well. > > More worrying, barebox does not support the : either. So there is a > danger your bootloader suddenly goes silent after a dt blob update. Since in barebox we use the upstream Kernel devicetrees it will be under our control when they arrive, so we can add support for that ':' before the new devicetrees arrive. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html