Hi Frank, > On May 16, 2015, at 05:16 , Frank Rowand <frowand.list@xxxxxxxxx> wrote: > > On 5/15/2015 5:47 PM, Frank Rowand wrote: >> On 5/12/2015 7:33 AM, Pantelis Antoniou wrote: >>> Hi Geert, >>> >>>> On May 12, 2015, at 14:56 , Geert Uytterhoeven <geert+renesas@xxxxxxxxx> wrote: >>>> >>>> This allows to handle device tree overlays like plain device trees. >>>> >>>> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> >>>> --- >>>> Questions: >>>> - Do we want dtso files under arch/<arch>/boot/dts/, too? >>>> - Do we want to move the dts files outside the kernel repository >>>> first? >>>> >>> >>> Oh that’s a nice hornet’s nest you’ve kicked here. >>> >>> arch/<arch>/boot/dts should not be the place, cause overlays are not related with boot per se. >>> As they are right now are board (family) specific. >> >> Aren't overlays meant to describe child boards (capes, shields, whatever) that may >> vary from system to system, but are not expected to be hot-plugged while the OS >> is up? Or is hot-plug a design goal? > > To reply to myself, there is a current discussion about whether to use overlays to > help with a powerpc pci desire to add and delete subtrees: > > http://www.spinics.net/lists/linux-pci/msg40740.html > > That sound like hot-plug to me… > Many people asked for overlays with hot-plugging probably busses like PCI and USB. Think about an FPGA on a PCI board that needs to be instantiated after insertion. Expect more activity on that particular front; probably this week. >> >> If no hot-plug, then to me an overlay is just as related to boot as the base dts. >> It is a mere implementation detail that overlays are "loaded" from userspace >> instead of by the booting kernel (I don't really know the details of using >> overlays, so please correct me if I am wrong about how the kernel becomes aware >> of an overlay). >> >>> >>> I think we should try to keep an external kernel repo with them for now until we >>> figure out where to put them. >>> >>>> scripts/Makefile.lib | 3 +++ >>>> 1 file changed, 3 insertions(+) >>>> >>>> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib >>>> index 79e86613712f2230..4b14eef1d4b2ce8f 100644 >>>> --- a/scripts/Makefile.lib >>>> +++ b/scripts/Makefile.lib >>>> @@ -292,6 +292,9 @@ cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \ >>>> $(obj)/%.dtb: $(src)/%.dts FORCE >>>> $(call if_changed_dep,dtc) >>>> >>>> +$(obj)/%.dtbo: $(src)/%.dtso FORCE >>>> + $(call if_changed_dep,dtc) >>>> + >>>> dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp) >>>> >>>> # Bzip2 >>>> -- >>>> 1.9.1 >>> >>> Regards >>> >>> — Pantelis Regards — Pantelis -- 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
