From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Denk Date: Sat, 15 Dec 2012 08:30:51 +0100 Subject: [U-Boot] [PATCH] ns16550: allow UART address to be set dynamically In-Reply-To: <50CBD313.60508@gmail.com> References: <1355354590-10023-1-git-send-email-swarren@wwwdotorg.org> <50C918A5.6090207@wwwdotorg.org> <20121213102950.17EC320120D@gemini.denx.de> <50CA1BB8.4000704@wwwdotorg.org> <20121213203604.1DD9F201213@gemini.denx.de> <50CA3E7A.8020407@wwwdotorg.org> <50CA4056.8060900@ti.com> <50CA437F.7060704@wwwdotorg.org> <50CB8ED1.7020503@ti.com> <20121214222646.9C55F200CDB@gemini.denx.de> <50CBB346.30208@gmail.com> <20121215003248.9BC712000ED@gemini.denx.de> <50CBD313.60508@gmail.com> Message-ID: <20121215073051.969102000ED@gemini.denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Dear Graeme Russ, In message <50CBD313.60508@gmail.com> you wrote: > > I can give you an example - Remote Telemetry Units (RTUs). They usually > have a number of serial ports. The number of ports may vary based on the > sub-model. Some ports may be RS-232, some may be RS-485 or RS-422. > Depending on what additional devices you want to communicate with, you may > need to use the 'console/diag' port to connect to a real device. So what > you want to do is route console to another port (if available) or even > netconsole. Netconsole is always an option, and I think we also support switching to other serial ports here and there (after relocation, that is). But if you need console output before relocation (i. e. during debugging), then I do not see why we cannot demand that the console port is statically configured, and that you need corectly configured images to have an early working console. > I do get your point of view. But I think a combination of storing the > dynamic console info in a DT format, the pre-console buffer and getting DT > available as early as possible can yield a 'non-cludgy' solution. For board > or SoC vendors who, for whatever reason, have implemented non-DT storage of > hardware enumeration data they will be stuck with the penalty of having to > translate that data into DT format before it can be parsed by U-Boot. Maybe > this could be done in SPL. Yes, it's a hack, but if it can't be worked > around, push it as low as possible and as far away from the U-Boot core as > possible I mostly agree here. But I still fail to see why we havet os upport this combination of early and dynamic - and only this is what causes some issues. Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de Neckties strangle clear thinking. -- Lin Yutang