Hi Maxime, On 26 June 2016 at 23:29, Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote: > Hi David, > > On Mon, Jun 27, 2016 at 01:37:19AM +1000, David Gibson wrote: >> On Fri, Jun 24, 2016 at 04:27:45PM +0200, Maxime Ripard wrote: >> > Hi, >> > >> > The device tree overlays are a great solution to the issue raised by >> > the bunch expandable boards we find everywhere these days, like the >> > Beaglebone, Raspberry Pi or CHIP. >> > >> > However, most of the time, the overlays are applied through a >> > mechanism involving the firmware request interface in Linux, that is >> > only fully functional once the userspace has been mounted and is >> > running. >> > >> > Some expansion boards might need to be enabled before that, because >> > they simply need to patch the DT early on, or need to be initialized >> > early in order to be fully functional, or because they provide access >> > to the root filesystem. >> > >> > In these cases, having the bootloader applying the overlay before >> > Linux starts seems like the easiest solution. >> > >> > This implementation doesn't provide all the Linux fancyness though, >> > there's no transactional application, which means that if the overlay >> > cannot be applied for a reason while you're still halfway through the >> > application, you're probably screwed. It also cannot remove an >> > overlay, but I don't think that it is currently a use-case. >> > >> > There's still a bunch of work to extend the libfdt unit tests to test >> > the new functions introduced, but these patches will be submitted >> > in a near future. >> >> Are you planning to send a new version of (the relevant portions of) >> these against upstream libfdt? > > Of course, I just only have to work on the test cases now. > > Simon wanted to merge this in U-Boot for the next merge window, and > then sync with libfdt when it would be merged, hence why I posted it > first. Yes I'll wait until after the current release as it is too close. Feel free to send a fix-up patch (or whatever means you prefer) once this is applied upstream. Regards, Simon -- To unsubscribe from this list: send the line "unsubscribe devicetree-compiler" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
