On Thu, Oct 24, 2013 at 10:17:33AM +0200, Thierry Reding wrote: > On Thu, Oct 24, 2013 at 10:06:24AM +0200, Sascha Hauer wrote: > > On Wed, Oct 23, 2013 at 12:54:35PM -0600, Jason Gunthorpe wrote: > > > On Wed, Oct 23, 2013 at 08:30:42PM +0200, Richard Cochran wrote: > > > > On Wed, Oct 23, 2013 at 12:25:02PM -0600, Jason Gunthorpe wrote: > > > > > > > > On ARM the package of 'stuff' can very reasonably include dtb. Distro > > > > > scripts can package modules+DTB+vmlinuz into something the bootloader > > > > > can understand. (The next pain point will be to standardize that) > > > > > > > > > > The DTB doesn't have to be 'outside' the distro/kernel to give users a > > > > > seamless upgrade experience. > > > > > > > > How can a distro possibly provide me a DTB? > > > > > > > > They don't know what hardware I am using. Only I know that. > > > > > > I'm not sure what you are asking? Treat DTBs like kernel drivers. If > > > you make hardware and you want distros to run on it, you have to > > > provide the DTB for that hardware to mainline+distros. > > > > > > Remember, there are two ways to view DTB: > > > a) It comes from the firmware and you have to live with whatever > > > crap the firmware does > > > b) It comes from the kernel, must match the kernel, and we don't > > > have to tolerate crap in the DTB. > > > > c) It comes from the firmware and is at least good enough to bring up a > > kernel to install a better devicetree. > > That's an interesting new view. And I think that makes a lot of sense > because it matches the product cycle pretty well. Typically I wouldn't > expect an upstream kernel to be fully featured when first shipped in a > product, for all the known reasons, but it should be possible to come > up with stable bindings good enough to perhaps boot to a command-line > prompt and have some way of accessing other files (network, block > device, ...). > > Then again you could argue that the bootloader should be able to update > itself (and the DTB while at it). barebox/u-boot usually can do this, but I think distributions can provide a much better and more consistent user interface. Also it offers a distribution to provide a way to update the devicetree. Otherwise the distributions can only say: See your boards documentation how to update the devicetree. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- 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
