On 08/16/17 15:33, Frank Rowand wrote: > On 08/16/17 14:59, Tom Rini wrote: >> Build the dtb file for these platfroms with __symbol__ information >> included. This will reduce the size of the dtb (and resident memory > > typo: reduce the size should be increase the size > > >> usage) in exchange for allowing more types of overlays to be applied to >> the dtb file prior to passing it to Linux and additional functionality >> within the kernel when OF_OVERLAY is enabled. >> >> Cc: Jason Kridner <[email protected]> >> Cc: Drew Fustini <[email protected]> >> Cc: Robert Nelson <[email protected]> >> Cc: Lokesh Vutla <[email protected]> >> Cc: Frank Rowand <[email protected]> >> Cc: Rob Herring <[email protected]> >> Cc: Mark Rutland <[email protected]> >> Cc: Russell King <[email protected]> >> Cc: [email protected] >> Cc: [email protected] >> Cc: [email protected] >> Signed-off-by: Tom Rini <[email protected]> >> --- >> This patch takes the path that Rob encouraged in my previous patch of >> enabling __symbols__ in some platforms now (that can use it) and see if >> a critical mass evolves that pushes towards -@ being default for all >> dtbs. I would suggest that the dra76 series be respun to include a hunk >> like this at least as well, and if there's another Beagle X15 patch, >> that too. Russell, per some of our conversations, something like would >> also be needed as part of using overlays to solve some of the problems >> with Hummingboard, etc. >> --- >> arch/arm/boot/dts/Makefile | 14 ++++++++++++++ >> 1 file changed, 14 insertions(+) >> >> diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile >> index 4b17f35dc9a7..6f98422ca00e 100644 >> --- a/arch/arm/boot/dts/Makefile >> +++ b/arch/arm/boot/dts/Makefile >> @@ -1063,3 +1063,17 @@ dtb-$(CONFIG_OF_ALL_DTBS) := $(patsubst >> $(dtstree)/%.dts,%.dtb, $(wildcard $(dts >> >> always := $(dtb-y) >> clean-files := *.dtb >> + >> +# enable creation of __symbols__ node >> +DTC_FLAGS_am335x-bone += -@ >> +DTC_FLAGS_am335x-boneblack += -@ >> +DTC_FLAGS_am335x-boneblack-wireless += -@ >> +DTC_FLAGS_am335x-boneblue += -@ >> +DTC_FLAGS_am335x-bonegreen += -@ >> +DTC_FLAGS_am335x-bonegreen-wireless += -@ >> +DTC_FLAGS_am57xx-beagle-x15 += -@ >> +DTC_FLAGS_am57xx-beagle-x15-revb1 += -@ >> +DTC_FLAGS_dra7-evm += -@ >> +DTC_FLAGS_dra72-evm += -@ >> +DTC_FLAGS_dra72-evm-revc += -@ >> +DTC_FLAGS_dra71-evm += -@ >> > > I would prefer that instead of "-@", a configurable value be used.
I stated that poorly. It was intended conceptually, not literally. One possible concrete implementation would be to use something other than DTC_FLAGS, for example DTC_FLAGS_EXTRA, then have the build system choose whether to fold DTC_FLAGS_EXTRA into DTC_FLAGS, based on some sort of configurable value. > The current form of the patch imposes the extra overhead even > for those who do not want to use any overlay. > > Using a kernel CONFIG_ value for the "configurable value" is not > desired because it adds a kernel configuration dependency to what > is contained in a dtb. I do not know if we can find another > better way to make this configurable. AMaybe Rob's suggestion > of a shell variable used in the make command. >
