From mboxrd@z Thu Jan 1 00:00:00 1970 From: balbi@ti.com (Felipe Balbi) Date: Fri, 26 Dec 2014 13:47:18 -0600 Subject: [PATCH] arm: omap: reduce zImage size on omap2plus_defconfig In-Reply-To: References: <20141223161936.GA9147@saruman> <549AA94A.8030209@compulab.co.il> <20141224154948.GA423@saruman> <20141224190401.GN23854@atomide.com> <549BE333.9060709@compulab.co.il> <20141226044246.GB7661@saruman> <549D4CEA.6090009@compulab.co.il> <20141226151907.GD17430@saruman> Message-ID: <20141226194718.GL17430@saruman> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, On Fri, Dec 26, 2014 at 08:38:10PM +0100, Javier Martinez Canillas wrote: > > I wonder the same thing, but look at multi_v7_defconfig today. Almost > > everything is built-in, which makes the kernel image enormous (5.5MiB). > > > >> to get rid of the SoC specific configs then and just use the single > >> ARMv7 defconfig for all SoCs with most of the options enabled as a > >> module? > > > > if people accept switching some of those as modules, sure. I don't mind > > that at all. I'll still continue to maintain my out-of-tree defconfigs > > for my boards anyway. It's also very good to have a generic defconfig > > which will just work with everything I have. > > > >> FYI, some time ago I posted a patch to enable SBS-compliant batteries > >> support as a module for Exynos defconfig and was told to re-spin the > >> patch and enabling it as built-in instead since the most popular use > >> case for exynos_defconfig was development and people usually just copy > >> the kernel binary and not the modules [0]. > > > > lol, that's the reason why I don't use multi_v7_defconfig. > > > > Agreed, on its current form I wonder what's the use case for > multi_v7_defconfig. I guess most options will slowly be changed to be > built as a module though to be similar to what distros do. that's the idea with omap2plus_defconfig, at least. Last I talked with Tony, the idea was "let's have a defconfig which distros can just use and almost everything is built as a module". > >> can use omap2plus_defconfig as a base. So, is or is not expected that > >> people will use omap2plus_defconfig as a base for their own config? > > > > I never claimed that people should not use it as a *base*, rather it > > should not be used to build a product's kernel/modules. Imagine you > > shipping an embedded product based off of OMAP5 and you add CPSW, QSPI, > > MUSB, a ton of touchscreen drivers you don't use, several PMIC drivers > > built-in, etc. It's a waste of space and just bloats that product's > > zImage. > > > > Got it, thanks for the clarification. I agree that omap2plus_defconfig > is very bloated to be used for products as-is. I also have custom > defconfig to test the OMAP boards I maintain which is basically > omap2plus_defconfig + a merged config fragment (using merge_config.sh) > that disables and enables needed options. right, I used to that too. But right now I just have a set of config-$board which I maintain locally. Slowly moving to omap2plus_defconfig only as I move all my boards to NFS root. > >> I think the problem is that there isn't an agreement about what is the > >> purpose of the per SoC (e.g: oma2plus_defconfig) and the multi_v7 > >> defconfigs (or at least is not well documented since I could not find > >> it). So, IMHO this concern should be raised to the ARM SoC maintainers > >> and there should be an agreement in the ARM community as a whole about > >> how things should be configured on each defconfig, and all SoCs should > >> follow the agreed rule. > > > > OTOH, the OMAP defconfig is part of the OMAP port and Tony will have the > > final saying about it, right ? > > > > Sorry, I didn't mean that Tony doesn't have the last word for omap > defconfig. My point was that it should be nice to get a consensus > about this and specially document it to make life easier for everyone. definitely, we need at least some documentation. No questions there. > People posting defconfig changes will know what the rule is and we can > avoid having these kind of discussions which I have had many times in > the past when posting defconfig changes and I'm sure I will have more > in the future again. right. > But I don't really mind tbh, I will keep maintaining my custom > defconfigs anyways and post wnen I think that enabling a config option > in a mainline defconfig makes sense and will do as a module or > built-in depending of what the SoC maintainer tells me to use. yeah, that's the downside, really. One maintainer prefers small zImage with several modules (which I very much like the idea) while another prefers giant zImage with virtually no modules :-) cheers -- balbi -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: Digital signature URL: