From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Date: Wed, 21 Nov 2012 10:13:10 +0000 Subject: [U-Boot] [PATCH 5/8] arm: Add boottime support for the ARM architecture In-Reply-To: <20121121093018.B3D082003CF@gemini.denx.de> References: <1353422034-28107-1-git-send-email-lee.jones@linaro.org> <1353422034-28107-6-git-send-email-lee.jones@linaro.org> <20121120182408.E497720009C@gemini.denx.de> <20121121091717.GG28265@gmail.com> <20121121093018.B3D082003CF@gemini.denx.de> Message-ID: <20121121101310.GL28265@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de > > > > This patch adds support for passing boot time information to > > > > the Linus kernel using ATAGS when booting on ARM based devices. > > > > > > I implicitly mentioned this before, here it comes clear again: > > > > Ah, this has been tried before? Sorry, I didn't know that. > > I expolained it in my reply to your cover letter, i.e. in the message > immediately preceeding the one you replied to here. So you're telling me off for sending a patch which doesn't agree with something you've said, despite you saying it _after_ I sent the patch? Sounds sensible. :) > > > I dislike the idea of adding such infrastructure in an archittecture > > > dependent way, knowing from day one that we cannot use this as is for > > > other architectures, and that the mechanism being used is even going > > > to go away for this architecutre, too. > > > > > > Please come up with a solution that works for all architectures > > > instead. > > > > So I guess Device Tree it is then. > > No. The device tree is for passing hardware information to U-Boot and > the kernel. It is NOT intended for carrying things like debug or > timing logs. It is not a good idea to misuse such services for things > they were not made for nor where they fit. Okay, got it. > Please use a standard facility, and one designed for such purposes > like the Linux log buffer for this purpose. As explained, this has > the added benefit that you don't need to change any Linux code. And > you can build on the (also existing) show_boot_progress() support in > U-Boot, so the extesions should actually be really small and pretty > clear. When you say log buffer, do you mean __log_buf? Doesn't this contain logs used for dmesg; thus won't all this crud end up in a user's dmesg kernel log? Unless there is another log which is used only for the kernel. Also, wouldn't I then have to write a text parser to process this information? Sounds horrendous. Hopefully, I have missed something and it's actually easier than what I've mentioned. -- Lee Jones Linaro ST-Ericsson Landing Team Lead Linaro.org ? Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog