On Mon, Apr 06, 2015 at 11:33:53AM +0200, Stefan Agner wrote: > On 2015-04-06 10:54, Russell King - ARM Linux wrote: > > On Mon, Apr 06, 2015 at 10:38:10AM +0200, Stefan Agner wrote: > >> We already prevent a kernel image which mixes V4/V4T/V5 and V6/V7. And > >> so we would do with V7M too. Just because it's in multiplatform doesn't > >> mean we need to mix things up. > > > > I don't think you're getting what I'm saying at all... :( > > It's not that I don't get it. I'm just arguing against it. > > IMHO, it's wrong to create a parallel universe for v7M multiplatform... > > Multiplatform as I understand it is mainly about selecting multiple SoC > _platforms_ but not necessarily multiple CPU platforms. It happens to > work well for V6/V7, but does not for others, and preventing > multiselection for incompatible CPU platforms is the way to prevent > creating such images. Let's be clear: I'm _not_ arguing against being able to select multiple SoC platforms at all. I'm merely arguing about how it should be done. What I'm saying, is that MULTIPLATFORM itself does _not_ work for all noMMU platforms. Yes, it _may_ work for V7M, but it doesn't work for previous generation stuff - and that's confusing. Let's look at what needs to happen to make V7M work the way you're suggesting: * Add "depends on !MMU" to all the existing ARCH_MULTI_* symbols. * Append "if MMU" to the selection of ARM_PATCH_PHYS_VIRT and AUTO_ZRELADDR in multiplatform. We then have the problem for the older generation noMMU stuff. Should we stuff into the multiplatform architecture options for selecting the older generation noMMU _platforms_ into the "CPU Core family selection" menu? That's clearly wrong because they're not "CPU Cores". So, we have to find somewhere else to put the older generation stuff, and by doing so, that causes confusion, because we now have to select multiplatform for one group of noMMU implementations, and _not_ select it for another group of noMMU implementations. Imagine yourself writing up a document describing how to configure the kernel for all noMMU platforms which will be read by many people with varying degrees of English comprehension across the world, and how you would describe to them, such that they clearly understood, how to choose the right options. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
