On Thu, 19 Jan 2012, Grant Likely wrote: > On Thu, Jan 19, 2012 at 10:50 AM, Russell King - ARM Linux > <[email protected]> wrote: > > On Thu, Jan 19, 2012 at 05:27:15PM +0000, Pawel Moll wrote: > >> On Thu, 2012-01-19 at 17:00 +0000, David Vrabel wrote: > >> > The problem wasn't with including skeleton.dtsi. > >> > >> Including as it is creates two device_type="memory" nodes, one with > >> regs=<0 0>, which is definitely wrong. > >> > >> > With > >> > CONFIG_ARM_ATAG_DTB_COMPAT the zImage decompressor modifies the appended > >> > DTB using information from the ATAGs (see atags_to_fdt()). > >> > > >> > If there's an ATAG giving the amount of RAM the DTB's "memory" node is > >> > replaced with a new one. Since the vexpress DTBs don't have a "memory" > >> > node it's added and the DTB ends up with two nodes describing memory. > >> > >> The "memory@address" node name is in my opinion perfectly legal - p. 3.4 > >> of the DT spec says "The name component of the node name (see 2.2.1) > >> shall be memory.". So the decompressor code may be wrong in looking for > >> adress-less "memory" node... > > > > I don't think you can expect such early code to properly parse a DT tree > > with a variability in how memory stuff is declared into that DT tree. > > > > What if you have two memory nodes specified in the DT file, and the > > ATAG data contains one? > > Yes, just because it is technically legal doesn't make it okay. The > pragmatic approach here is that the skeleton.dtsi file calls the node > "memory", so this .dts file must do the same. > > > The more I look at this, the more I'm convinced that Grant's idea that > > DT should entirely override ATAGs all the way to the kernel proper was > > the wrong solution - at least in the kernel, if we had both available, > > we could make a choice there, and have the full DT library to be able > > to manipulate the DT blob. > > Hey! I was originally lobbying for the dt pointer carried by an ATAG. > Nico conviced me otherwise. :-)
Hey! I was originally lobbying for people to have a fully DT aware bootloader if they wanted to play with DT, otherwise there is no incentive for updated bootloaders. But someone else convinced me otherwise. :-) Mixed bags always have loose ends. Nicolas
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