Messages in this thread | | | Subject | Re: [RFC PATCH v2 0/4] Add device tree build information | From | Alexandre Torgue <> | Date | Mon, 2 Mar 2020 13:55:55 +0100 |
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Hi Franck
On 2/28/20 6:47 PM, Frank Rowand wrote: > Hi Alexandred, > > Ping. >
Sorry I was off last week.
> -Frank > > > On 2/21/20 11:47 AM, Frank Rowand wrote: >> On 2/21/20 10:14 AM, Alexandre Torgue wrote: >>> (with title it's better ;) >>> >>> Hi, >>> >>> The goal of this series is to add device tree build information in dtb. >>> This information can be dtb build date, where devicetree files come from, >>> who built the dtb ... Actually, same kind of information that you can find >>> in the Linux banner which is printout during kernel boot. Having the same >>> kind of information for device tree is useful for debugging and maintenance. >>> >>> A file (dtb-build.txt) containing a string with build information (e.g., >>> >From Linux 5.5.0-rc1 by alex the Mon Jan 13 18:25:38 CET 2020) is generated by >>> "gen_dtb_build_info.sh" script. >>> >>> This file has to be included manually in each dts file that would like to use >>> this build information. >> >> In the RFC series, you said: >> >> "I gonna prepare a V2 with David proposition (to use overlay format) by >> keeping in mind not to modify existing dts(i) files." >> >> https://lore.kernel.org/linux-devicetree/9d83a36c-78c5-3452-bb48-209d68c46038@st.com/ >> >> But here in v2 instead requires including dtb-build.txt. >> >> This would require modifying every single main .dts file to get the build info >> I would prefer the method that Ian and David came up with (sorry, no lore link, >> it did not go to lkml). Extract from David's email: >> >> Date: Tue, 21 Jan 2020 13:05:25 +1100 >> From: David Gibson <david@gibson.dropbear.id.au> >> Subject: Re: [RFC PATCH 1/3] dtc: Add dtb build information option >> >> > Given that dts files are run through the C preprocessor before being >> > fed to dtc, the build script could use the '-include' flag to force- >> > include a fragment containing generated build info without any need to >> > modify existing dts files. >> >> Uh... maybe. -include will essentially prepend the forced file, which >> is a bit awkward for our purposes. It means that the prepended file >> would need the /dts-v1/ tag, and we couldn't have it in the main files >> which would be a bit confusing. I think it would also cause problems >> with any /memreserve/ tags and means that the main tree could in >> theory overwrite the build information which we don't necessarily >> want. >> >> I guess we could build things the other way around: have the main .dts >> file specified with -include and have the dts on the dtc commandline >> be a fixed one with the build information. It'd be a little weird, >> though. >> >> -Frank
Yes. I try briefly this idea but I got issues with dts-v1 tag. I agree, it is cleaner to not modify input dts file. I can rework int this way.
regards Alex
>> >>> >>> of/fdt.c is modified to printout "build-info" property during Kernel boot and >>> scripts/Makefile.lib is modified to call "gen_dtb_build_info.sh" script. >>> >>> Patch 1 & 2 script and of/fdt.c updates >>> Patch 3 is an example of use in stm32mp157c-dk2.dts file. >>> Patch 4 is a tentative to make it automatic (not yet 100% functional). >>> >>> regards >>> Alex >>> >>> Changes since v1; >>> - Remove modification in dtc (no more -B option) >>> - Generate a file containing build info which is directly included in dts >>> file. >>> >>> >>> Regards >>> Alex >>> >>> Alexandre Torgue (4): >>> scripts: Add script to generate dtb build information >>> of: fdt: print dtb build information >>> ARM: dts: stm32: Add dtb build information entry for stm32mp157c-dk2 >>> script: make automatic dtb build info generation >>> >>> arch/arm/boot/dts/stm32mp157c-dk2.dts | 1 + >>> drivers/of/fdt.c | 9 +++++++++ >>> scripts/Makefile.lib | 3 +++ >>> scripts/gen_dtb_build_info.sh | 12 ++++++++++++ >>> 4 files changed, 25 insertions(+) >>> create mode 100755 scripts/gen_dtb_build_info.sh >>> >> >> >
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