Re: [RFC PATCH 0/3] Add device tree build information

[Alexandre Torgue]

Hi Franck

On 1/17/20 8:13 PM, Frank Rowand wrote:
> On 1/16/20 2:19 AM, Alexandre Torgue wrote:
> > Hi Franck,
> >
> > On 1/16/20 3:28 AM, Frank Rowand wrote:
> > > On 1/13/20 12:16 PM, Alexandre Torgue wrote:
> > > > 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.
> > > >
> > > > To achieve that a new option "-B" (using an argument) is added to dtc.
> > > > The argument is a file 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).
> > > > DTC use it to append dts file with a new string property "Build-info".
> > > >
> > > > of/fdt.c is modified to printout "Build-info" property during Kernel boot and
> > > > scripts/Makefile.lib is modified to use dtc -B option during kernel make (this
> > > > last part could be improved for sure).
> > >
> > > Please read through the thread at:
> > >
> > >  ÂÂ https://lore.kernel.org/linux-arm-kernel/550A42AC.8060104@xxxxxxxxx/
> > >
> > > which was my attempt to do something similar.
> >
> > Yes the idea is the same: get build DTB information like build date,
> > "who built the DTB" ... The difference seems to be the way to do it.
> > In my case, I don't want to modify existing dts source files., but I
> > "just" append them by creating a new property with a string
> > containing this build information.>
> > Why your proposition has not been accepted ?
>
> Since you are asking this question, I am presuming that you did not
> read the replies in the thread I referenced.  Please read through
> the entire thread.  Most of the review comments were objecting to
> the concept of my proposal.

Sorry I have been lazy :$. This series is a tiny one compare to yours, 
and adds less dtb information (only git used, who built dtb and the 
date). There are no "dtb versions", and "absolute/relative" path which 
created concerns. One remaining concern is "reproducible build" but 
making dtb info optional could respond to it.
I continue to think that it's useful to get those information (even if 
it's only a string) But before continuing (and find a better technical 
way to do it), I need to know if there are no other obstacles.


Regards
Alex


> -Frank
>
> > Regards
> > Alex
> >
> > > -Frank
> > >
> > > > Regards
> > > > Alex
> > > >
> > > > Alexandre Torgue (3):
> > > >  ÂÂ dtc: Add dtb build information option
> > > >  ÂÂ of: fdt: print dtb build information
> > > >  ÂÂ scripts: Use -B dtc option to generate dtb build information.
> > > >
> > > >  Â drivers/of/fdt.cÂÂÂÂÂÂÂÂÂÂ |Â 9 +++++++
> > > >  Â scripts/Makefile.libÂÂÂÂÂÂ | 11 +++++---
> > > >  Â scripts/dtc/dtc.cÂÂÂÂÂÂÂÂÂ | 55 +++++++++++++++++++++++++++++++++-----
> > > >  Â scripts/gen_dtb_build_info | 11 ++++++++
> > > >  Â 4 files changed, 76 insertions(+), 10 deletions(-)
> > > >  Â create mode 100755 scripts/gen_dtb_build_info