| Message ID | 20170331150153.14606-2-nikolaus.schulz@avionic-design.de |
|---|---|
| State | Accepted |
| Headers | show |
On 03/31/2017 09:01 AM, Nikolaus Schulz wrote: > Creating the emmc image requires creating the bct file and the > bootloader image first. These dependencies are written to a makefile > snippet that is created by the gen-image-deps.sh script. But that > script is only invoked when the rule that creates the emmc image is run, > which is too late for creating the dependencies makefile. > > Add a rule to post.mk that tells make how to create the dependencies > makefile; with that in place, make automatically makes the dependency > makefile before executing any other rules. I don't think this change is correct, or at least necessary. The concept here is that: - If an output file does not exist at all, it will be built for the first time, and a dependency file will be generated for the next time. - If an output file does exist, the related dependency file is also expected to exist, and specify the dependencies, so that if they change, a rebuild will occur. In particular, the dependency file is/should-no-be necessary in the case where an output file is to be generated for the first time. If a known dependency specification is missing, we should specify it directly in the makefile itself. The generated dependency files are intended to represent unknown/unknowable dependencies. Is it possible to fix this problem that way instead? -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Mar 31, 2017 at 09:46:19AM -0600, Stephen Warren wrote: > On 03/31/2017 09:01 AM, Nikolaus Schulz wrote: > > Creating the emmc image requires creating the bct file and the > > bootloader image first. These dependencies are written to a makefile > > snippet that is created by the gen-image-deps.sh script. But that > > script is only invoked when the rule that creates the emmc image is run, > > which is too late for creating the dependencies makefile. > > > > Add a rule to post.mk that tells make how to create the dependencies > > makefile; with that in place, make automatically makes the dependency > > makefile before executing any other rules. > > I don't think this change is correct, or at least necessary. > > The concept here is that: > > - If an output file does not exist at all, it will be built for the first > time, and a dependency file will be generated for the next time. > > - If an output file does exist, the related dependency file is also expected > to exist, and specify the dependencies, so that if they change, a rebuild > will occur. > > In particular, the dependency file is/should-no-be necessary in the case > where an output file is to be generated for the first time. > > If a known dependency specification is missing, we should specify it > directly in the makefile itself. The generated dependency files are intended > to represent unknown/unknowable dependencies. > > Is it possible to fix this problem that way instead? Well, the dependencies in question are hard dependencies: creating the emmc image has the bct file and the bootloader image as prerequisites. I just noticed though that specifying the dependency on the bct file need not use gen-image-deps.sh at all, since the bct filename is already known to make. I'll send an alternate, trivial patch. Note that the dependency on the bootloader image can be added to the makefiles in a similar way by simply adding a variable for the filename to the per-soc Makefiles and make that a prerequisite of the emmc image. With that there is no need for a dynamically generated dependency file at all, at the slight expense of some (more) duplication of filenames. I'll send a separate patch doing that as an RFC. Regards, Nikolaus
On 04/03/2017 06:22 AM, Nikolaus Schulz wrote: > On Fri, Mar 31, 2017 at 09:46:19AM -0600, Stephen Warren wrote: >> On 03/31/2017 09:01 AM, Nikolaus Schulz wrote: >>> Creating the emmc image requires creating the bct file and the >>> bootloader image first. These dependencies are written to a makefile >>> snippet that is created by the gen-image-deps.sh script. But that >>> script is only invoked when the rule that creates the emmc image is run, >>> which is too late for creating the dependencies makefile. >>> >>> Add a rule to post.mk that tells make how to create the dependencies >>> makefile; with that in place, make automatically makes the dependency >>> makefile before executing any other rules. >> >> I don't think this change is correct, or at least necessary. >> >> The concept here is that: >> >> - If an output file does not exist at all, it will be built for the first >> time, and a dependency file will be generated for the next time. >> >> - If an output file does exist, the related dependency file is also expected >> to exist, and specify the dependencies, so that if they change, a rebuild >> will occur. >> >> In particular, the dependency file is/should-no-be necessary in the case >> where an output file is to be generated for the first time. >> >> If a known dependency specification is missing, we should specify it >> directly in the makefile itself. The generated dependency files are intended >> to represent unknown/unknowable dependencies. >> >> Is it possible to fix this problem that way instead? > > Well, the dependencies in question are hard dependencies: creating the > emmc image has the bct file and the bootloader image as prerequisites. > > I just noticed though that specifying the dependency on the bct file > need not use gen-image-deps.sh at all, since the bct filename is already > known to make. I'll send an alternate, trivial patch. > > Note that the dependency on the bootloader image can be added to the > makefiles in a similar way by simply adding a variable for the filename > to the per-soc Makefiles and make that a prerequisite of the emmc image. > With that there is no need for a dynamically generated dependency file > at all, at the slight expense of some (more) duplication of filenames. > > I'll send a separate patch doing that as an RFC. As mentioned in response to the followup patches you sent, I've decided to apply this patch instead. It's now applied. Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/build/post.mk b/build/post.mk index 979d8ce..a647c81 100644 --- a/build/post.mk +++ b/build/post.mk @@ -21,11 +21,12 @@ bcts: $(bcts) images: $(images) image_deps := $(addprefix .,$(addsuffix .d,$(images))) +$(image_deps): .%.d : %.cfg + ../../../build/gen-image-deps.sh $< $(@:.%.d=%) $@ -include $(image_deps) %.bct: %.bct.cfg cbootimage -gbct -$(soc) $< $@ %.img: %.img.cfg - ../../../build/gen-image-deps.sh $< $@ .$@.d cbootimage -$(soc) $< $@
Creating the emmc image requires creating the bct file and the bootloader image first. These dependencies are written to a makefile snippet that is created by the gen-image-deps.sh script. But that script is only invoked when the rule that creates the emmc image is run, which is too late for creating the dependencies makefile. Add a rule to post.mk that tells make how to create the dependencies makefile; with that in place, make automatically makes the dependency makefile before executing any other rules. Signed-off-by: Nikolaus Schulz <nikolaus.schulz@avionic-design.de> --- build/post.mk | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)