From mboxrd@z Thu Jan 1 00:00:00 1970 From: kaloz@openwrt.org (Imre Kaloz) Date: Fri, 26 Aug 2016 22:30:47 +0200 Subject: [PATCH 0/8] Convert Netgear WNR854T to devicetree In-Reply-To: References: <1468679348-10522-1-git-send-email-jm@lentin.co.uk> <1472203264-21089-1-git-send-email-jm@lentin.co.uk> <20160826143358.GI25046@lunn.ch> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, 26 Aug 2016 18:50:33 +0200, Jamie Lentin wrote: > On Fri, 26 Aug 2016, Andrew Lunn wrote: > >>>> - the factory layout gives you almost no space to play with >> >> Given that the kernel has grown in size over the years, does the >> mainline kernel fit in the factory layout? > > The factory layout has a 6MB JFFS2 for root & uImage (uboot mounts it by > default) + 1MB miscellany. So the main restriction on kernel size is the > size of your userland. > > The non-DT mainline layout is 1MB JFFS2 for uImage + 7MB rootfs. Which > is a closer approximation to other devices with a uImage in it's own > partition. > >>> Of course, one could also argue I'm breaking backwards compatibility >>> at this point by changing it, so maybe I should put it back. >> >> I don't mind breaking backwards compatibility, if the factory defaults >> no longer actually work..... >> >> Also, lets think about the users here. This is a very old box. Anybody >> playing with one are probably of the sort who tinker with a classic >> car in the garage, taking the engine apart and putting it back >> together again. I doubt there are users of this box who take their car >> in for a service once they are out of windscreen washing water. > > My line of thinking was that the only people that will see this default > partition scheme are people that have just compiled a mainline kernel > and booted it to see what happens. At which point you probably still > have the Netgear image in Flash. If you had OpenWRT in Flash then in all > likelihood you'd already be using an OpenWRT kernel too, with it's own > flash layout. Finally, you could have rolled your own userland and put > that on Flash, but by then you should know enough to do what you like :) Well, that means you have serial console - otherwise without userland it's pretty unusable ;) Anyways, I would stay with a modified version of the non-DT partitions, with the kernel size increased to ~1.4MB (didn't check how much overhead is DT support). Imre