On 04/03/2013 11:30 PM, Vineet Gupta wrote: > On 04/03/2013 09:48 PM, Stephen Warren wrote: >> On 04/03/2013 01:14 AM, Vineet Gupta wrote: >>> forgot to CC linux-arch >>> >>> On 04/03/2013 12:42 PM, Vineet Gupta wrote: >>>> Currently, for every ARC kernel build I see the following: >>>> >>>> --------------->8----------------- >>>> DTB arch/arc/boot/dts/angel4.dtb.S >>>> AS arch/arc/boot/dts/angel4.dtb.o >>>> LD arch/arc/boot/dts/built-in.o >>>> rm arch/arc/boot/dts/angel4.dtb.S <-- forces rebuild next iter >>>> CHK kernel/config_data.h >>>> --------------->8----------------- >> I assume that's because the file is an intermediate file, and only built >> due to a chain of build rules, and hence make clean it up itself after >> the build? > > Indeed - I should have made that explicit in the Changelog. > >>>> +.PRECIOUS: $(obj)/%.dtb.S >>>> + >>>> $(obj)/%.dtb.S: $(obj)/%.dtb >>>> $(call cmd,dt_S_dtb) >> I'm not sure if .PRECIOUS is correct here. That prevents make from >> deleting the file if make is CTRL-C'd in the middle of generating it. >> Couldn't that leave a stale/corrupt file around that'd break the build. >> Judging by: >> >> http://www.gnu.org/software/make/manual/html_node/Special-Targets.html >> >> I think .SECONDARY might be a better choice? Does that solve the problem >> you're seeing? > > Technically .SECONDARY is better - however it doesn't seem to work. Hmmm. It does for me. $ make --version GNU Make 3.81 I hacked the ARM makefiles as follows: diff --git a/arch/arm/Makefile b/arch/arm/Makefile index 4737408..70247c6 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -256,6 +256,7 @@ core-y += arch/arm/kernel/ arch/arm/mm/ arch/arm/common/ core-y += arch/arm/net/ core-y += arch/arm/crypto/ core-y += $(machdirs) $(platdirs) +core-y += arch/arm/boot/dts/ drivers-$(CONFIG_OPROFILE) += arch/arm/oprofile/ diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile index dedca49..af2202e 100644 --- a/arch/arm/boot/dts/Makefile +++ b/arch/arm/boot/dts/Makefile @@ -197,3 +197,5 @@ dtbs: $(addprefix $(obj)/, $(dtb-y)) $(Q)rm -f $(obj)/../*.dtb clean-files := *.dtb + +obj-y += tegra20-test.dtb.o and manually created a tegra20-test.dts. For reasons I didn't bother investigating, the .dtb.S -> .dtb.o conversion failed with syntax errors, and because the .dtb.S file was an intermediate file, make rm's it in this case. That's exactly the issue you're seeing. I then added the following to Makefile.lib: diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index a0ab6d7..fc11a67 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -258,6 +258,8 @@ cmd_dt_S_dtb= \ echo '.balign STRUCT_ALIGNMENT'; \ ) > $@ +.SECONDARY: $(obj)/%.dtb.S + $(obj)/%.dtb.S: $(obj)/%.dtb $(call cmd,dt_S_dtb) and no longer see make rm'ing the .dtb.S file. So, the .SECONDARY is behaving as expected, and should fix your problem. One other problem this highlighted: Unless you also mark the generated .dtb file as PRECIOUS/SECONDARY (or unless that DTB is included in targets for some reason) then make also rm's that, since it considers it intermediate: DTC arch/arm/boot/dts/tegra20-test.dtb DTB arch/arm/boot/dts/tegra20-test.dtb.S AS arch/arm/boot/dts/tegra20-test.dtb.o [error] rm arch/arm/boot/dts/tegra20-test.dtb So, your patch would probably need modification to apply the fix to *.dtb too, since they might also be intermediate? Perhaps add something like the following to arch/arc/boot/dts/Makefile? .SECONDARY: $(obj)/$(builtindtb-y).dtb > Running make with various debug toggles doesn't seem to be helping with why > .PRECIOUS works but not this. > That is also likely reason for a bunch of other .PRECIOUS entries in the same file > but no .SECONDARY. The existing .PRECIOUS exist to support lexer/yacc files, for which both the source .l/.y files are checked in, and the generated %.lex.c_shipped/%.tab.[cl]_shipped are also checked in. In this case, the "_shipped" files must be marked PRECIOUS, since they're under source control and hence should never be deleted. I don't believ this same situation applies to the .dtb.S files you're having problems with, so I don't think .PRECIOUS is correct for them. -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
