[RFC PATCH v2 0/4] Add device tree build information

[RFC PATCH v2 0/4] Add device tree build information

[Alexandre Torgue]

(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.

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

-- 
2.17.1

[RFC PATCH v2 1/4] scripts: Add script to generate dtb build information

[Alexandre Torgue]

This commit adds a new script to create a file (in dts file directory) with
some information (date, Linux version, user). This file could then be used
to populate "build-info" property in every dts file that would use this
build information:

Example:

/ {
	...
	build-info = /incbin/("dtb-build.txt");
	...
};

Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index bae62549e3d2..a5af84ef4ffc 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -246,6 +246,7 @@ quiet_cmd_gzip = GZIP    $@
 # DTC
 # ---------------------------------------------------------------------------
 DTC ?= $(objtree)/scripts/dtc/dtc
+DTB_GEN_INFO ?= $(objtree)/scripts/gen_dtb_build_info.sh
 
 # Disable noisy checks by default
 ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
@@ -286,6 +287,7 @@ $(obj)/%.dtb.S: $(obj)/%.dtb FORCE
 
 quiet_cmd_dtc = DTC     $@
 cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
+	$(DTB_GEN_INFO) $(src) ; \
 	$(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
 	$(DTC) -O $(2) -o $@ -b 0 \
 		$(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
diff --git a/scripts/gen_dtb_build_info.sh b/scripts/gen_dtb_build_info.sh
new file mode 100755
index 000000000000..0cd8bd98e410
--- /dev/null
+++ b/scripts/gen_dtb_build_info.sh
@@ -0,0 +1,10 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+set -o nounset
+
+DTB_DIR=$1
+DTB_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')
+DTB_INFO="From Linux $KERNELRELEASE by $DTB_COMPILE_BY the $(date).\0"
+
+printf "$DTB_INFO" > "$DTB_DIR/dtb-build.txt"
-- 
2.17.1

[RFC PATCH v2 2/4] of: fdt: print dtb build information

[Alexandre Torgue]

This commit prints out DTB build information (build time, dts source
version used, ...) if "Build-info" property exists in DTB root node.

Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 2cdf64d2456f..aa5989039746 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -1224,9 +1224,18 @@ bool __init early_init_dt_scan(void *params)
  */
 void __init unflatten_device_tree(void)
 {
+	const char *build_info;
+	unsigned long dt_root;
+
 	__unflatten_device_tree(initial_boot_params, NULL, &of_root,
 				early_init_dt_alloc_memory_arch, false);
 
+	/* If available, provide dtb build information */
+	dt_root = of_get_flat_dt_root();
+	build_info = of_get_flat_dt_prop(dt_root, "build-info", NULL);
+	if (build_info)
+		pr_info("%s\n", build_info);
+
 	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
 	of_alias_scan(early_init_dt_alloc_memory_arch);
 
-- 
2.17.1

[RFC PATCH v2 3/4] ARM: dts: stm32: Add dtb build information entry for stm32mp157c-dk2

[Alexandre Torgue]

dtb-build.txt is a file containing device tree build information (date,
source version ...). This file is used to fill "build-info" entry which
will be displayed during kernel boot.

Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

diff --git a/arch/arm/boot/dts/stm32mp157c-dk2.dts b/arch/arm/boot/dts/stm32mp157c-dk2.dts
index 7985b80967ca..387d3bcf5fa3 100644
--- a/arch/arm/boot/dts/stm32mp157c-dk2.dts
+++ b/arch/arm/boot/dts/stm32mp157c-dk2.dts
@@ -15,6 +15,7 @@
 / {
 	model = "STMicroelectronics STM32MP157C-DK2 Discovery Board";
 	compatible = "st,stm32mp157c-dk2", "st,stm32mp157";
+	build-info = /incbin/("dtb-build.txt");
 
 	aliases {
 		ethernet0 = &ethernet0;
-- 
2.17.1

[RFC PATCH v2 4/4] script: make automatic dtb build info generation

[Alexandre Torgue]

Append each "xxx.dtb.dts.tmp" file with "build-info" entry during dtb
build. It allows to get build information (date, source version, ...)
for each device tree without modify them manually.

Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index a5af84ef4ffc..f084e78267b2 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -289,6 +289,7 @@ quiet_cmd_dtc = DTC     $@
 cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
 	$(DTB_GEN_INFO) $(src) ; \
 	$(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
+	$(DTB_GEN_INFO) $(src) $(dtc-tmp) ; \
 	$(DTC) -O $(2) -o $@ -b 0 \
 		$(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
 		-d $(depfile).dtc.tmp $(dtc-tmp) ; \
diff --git a/scripts/gen_dtb_build_info.sh b/scripts/gen_dtb_build_info.sh
index 0cd8bd98e410..72f31e386787 100755
--- a/scripts/gen_dtb_build_info.sh
+++ b/scripts/gen_dtb_build_info.sh
@@ -6,5 +6,7 @@ set -o nounset
 DTB_DIR=$1
 DTB_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')
 DTB_INFO="From Linux $KERNELRELEASE by $DTB_COMPILE_BY the $(date).\0"
+DTS_FILE=$2
 
-printf "$DTB_INFO" > "$DTB_DIR/dtb-build.txt"
+printf "$DTB_INFO" > "arch/arm/boot/dts/dtb-build.txt"
+echo "&{/} {build-info = /incbin/(\"dtb-build.txt\");};" >> $DTS_FILE
-- 
2.17.1

Re: [RFC PATCH v2 0/4] Add device tree build information

[Frank Rowand]

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

> 
> 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
> 

Re: [RFC PATCH v2 1/4] scripts: Add script to generate dtb build information

[Frank Rowand]

On 2/21/20 10:14 AM, Alexandre Torgue wrote:
> This commit adds a new script to create a file (in dts file directory) with
> some information (date, Linux version, user). This file could then be used
> to populate "build-info" property in every dts file that would use this
> build information:
> 
> Example:
> 
> / {
> 	...
> 	build-info = /incbin/("dtb-build.txt");

s/.txt/.dtsi/

and same wherever the file name is used.


> 	...
> };
> 
> Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>
> 
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index bae62549e3d2..a5af84ef4ffc 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -246,6 +246,7 @@ quiet_cmd_gzip = GZIP    $@
>  # DTC
>  # ---------------------------------------------------------------------------
>  DTC ?= $(objtree)/scripts/dtc/dtc
> +DTB_GEN_INFO ?= $(objtree)/scripts/gen_dtb_build_info.sh
>  
>  # Disable noisy checks by default
>  ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
> @@ -286,6 +287,7 @@ $(obj)/%.dtb.S: $(obj)/%.dtb FORCE
>  
>  quiet_cmd_dtc = DTC     $@
>  cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
> +	$(DTB_GEN_INFO) $(src) ; \
>  	$(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
>  	$(DTC) -O $(2) -o $@ -b 0 \
>  		$(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
> diff --git a/scripts/gen_dtb_build_info.sh b/scripts/gen_dtb_build_info.sh
> new file mode 100755
> index 000000000000..0cd8bd98e410
> --- /dev/null
> +++ b/scripts/gen_dtb_build_info.sh
> @@ -0,0 +1,10 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +
> +set -o nounset
> +
> +DTB_DIR=$1
> +DTB_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')
> +DTB_INFO="From Linux $KERNELRELEASE by $DTB_COMPILE_BY the $(date).\0"

I would remove the filler words "From", "by", "the", and the trailing
period ('.').

<bikeshed>
You might consider using a format more like the Linux
kernel version line, which puts parenthesis around the
compiled by info.
</bikeshed>

-Frank

> +
> +printf "$DTB_INFO" > "$DTB_DIR/dtb-build.txt"
> 

Re: [RFC PATCH v2 4/4] script: make automatic dtb build info generation

[Frank Rowand]

On 2/21/20 10:14 AM, Alexandre Torgue wrote:
> Append each "xxx.dtb.dts.tmp" file with "build-info" entry during dtb
> build. It allows to get build information (date, source version, ...)
> for each device tree without modify them manually.
> 
> Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>
> 
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index a5af84ef4ffc..f084e78267b2 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -289,6 +289,7 @@ quiet_cmd_dtc = DTC     $@
>  cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
>  	$(DTB_GEN_INFO) $(src) ; \
>  	$(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
> +	$(DTB_GEN_INFO) $(src) $(dtc-tmp) ; \
>  	$(DTC) -O $(2) -o $@ -b 0 \
>  		$(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
>  		-d $(depfile).dtc.tmp $(dtc-tmp) ; \
> diff --git a/scripts/gen_dtb_build_info.sh b/scripts/gen_dtb_build_info.sh
> index 0cd8bd98e410..72f31e386787 100755
> --- a/scripts/gen_dtb_build_info.sh
> +++ b/scripts/gen_dtb_build_info.sh
> @@ -6,5 +6,7 @@ set -o nounset
>  DTB_DIR=$1
>  DTB_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')
>  DTB_INFO="From Linux $KERNELRELEASE by $DTB_COMPILE_BY the $(date).\0"
> +DTS_FILE=$2
>  
> -printf "$DTB_INFO" > "$DTB_DIR/dtb-build.txt"
> +printf "$DTB_INFO" > "arch/arm/boot/dts/dtb-build.txt"
> +echo "&{/} {build-info = /incbin/(\"dtb-build.txt\");};" >> $DTS_FILE
> 

Whatever the correct version of this ends up being, it should be
implemented as a single patch instead of patch 1/4 being modified
by patch 4/4.

Re: [RFC PATCH v2 1/4] scripts: Add script to generate dtb build information

[Rob Herring]

On Fri, Feb 21, 2020 at 11:52 AM Frank Rowand <frowand.list@gmail.com> wrote:
>
> On 2/21/20 10:14 AM, Alexandre Torgue wrote:
> > This commit adds a new script to create a file (in dts file directory) with
> > some information (date, Linux version, user). This file could then be used
> > to populate "build-info" property in every dts file that would use this
> > build information:
> >
> > Example:
> >
> > / {
> >       ...
> >       build-info = /incbin/("dtb-build.txt");
>
> s/.txt/.dtsi/
>
> and same wherever the file name is used.
>
>
> >       ...
> > };
> >
> > Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>
> >
> > diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> > index bae62549e3d2..a5af84ef4ffc 100644
> > --- a/scripts/Makefile.lib
> > +++ b/scripts/Makefile.lib
> > @@ -246,6 +246,7 @@ quiet_cmd_gzip = GZIP    $@
> >  # DTC
> >  # ---------------------------------------------------------------------------
> >  DTC ?= $(objtree)/scripts/dtc/dtc
> > +DTB_GEN_INFO ?= $(objtree)/scripts/gen_dtb_build_info.sh
> >
> >  # Disable noisy checks by default
> >  ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
> > @@ -286,6 +287,7 @@ $(obj)/%.dtb.S: $(obj)/%.dtb FORCE
> >
> >  quiet_cmd_dtc = DTC     $@
> >  cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
> > +     $(DTB_GEN_INFO) $(src) ; \
> >       $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
> >       $(DTC) -O $(2) -o $@ -b 0 \
> >               $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
> > diff --git a/scripts/gen_dtb_build_info.sh b/scripts/gen_dtb_build_info.sh
> > new file mode 100755
> > index 000000000000..0cd8bd98e410
> > --- /dev/null
> > +++ b/scripts/gen_dtb_build_info.sh
> > @@ -0,0 +1,10 @@
> > +#!/bin/bash
> > +# SPDX-License-Identifier: GPL-2.0
> > +
> > +set -o nounset
> > +
> > +DTB_DIR=$1
> > +DTB_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')
> > +DTB_INFO="From Linux $KERNELRELEASE by $DTB_COMPILE_BY the $(date).\0"
>
> I would remove the filler words "From", "by", "the", and the trailing
> period ('.').
>
> <bikeshed>
> You might consider using a format more like the Linux
> kernel version line, which puts parenthesis around the
> compiled by info.

IMO, we should use exactly the Linux kernel version line. Or exactly
the u-boot version line when built in u-boot.

Rob

Re: [RFC PATCH v2 1/4] scripts: Add script to generate dtb build information

[David Gibson]

[-- Attachment #1: Type: text/plain, Size: 2640 bytes --]

On Fri, Feb 21, 2020 at 11:52:34AM -0600, Frank Rowand wrote:
> On 2/21/20 10:14 AM, Alexandre Torgue wrote:
> > This commit adds a new script to create a file (in dts file directory) with
> > some information (date, Linux version, user). This file could then be used
> > to populate "build-info" property in every dts file that would use this
> > build information:
> > 
> > Example:
> > 
> > / {
> > 	...
> > 	build-info = /incbin/("dtb-build.txt");
> 
> s/.txt/.dtsi/

I don't think that makes sense.  This is an /incbin/ not an /include/
so the text file is *not* dts information.

> and same wherever the file name is used.
> 
> 
> > 	...
> > };
> > 
> > Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>
> > 
> > diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> > index bae62549e3d2..a5af84ef4ffc 100644
> > --- a/scripts/Makefile.lib
> > +++ b/scripts/Makefile.lib
> > @@ -246,6 +246,7 @@ quiet_cmd_gzip = GZIP    $@
> >  # DTC
> >  # ---------------------------------------------------------------------------
> >  DTC ?= $(objtree)/scripts/dtc/dtc
> > +DTB_GEN_INFO ?= $(objtree)/scripts/gen_dtb_build_info.sh
> >  
> >  # Disable noisy checks by default
> >  ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
> > @@ -286,6 +287,7 @@ $(obj)/%.dtb.S: $(obj)/%.dtb FORCE
> >  
> >  quiet_cmd_dtc = DTC     $@
> >  cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
> > +	$(DTB_GEN_INFO) $(src) ; \
> >  	$(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
> >  	$(DTC) -O $(2) -o $@ -b 0 \
> >  		$(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
> > diff --git a/scripts/gen_dtb_build_info.sh b/scripts/gen_dtb_build_info.sh
> > new file mode 100755
> > index 000000000000..0cd8bd98e410
> > --- /dev/null
> > +++ b/scripts/gen_dtb_build_info.sh
> > @@ -0,0 +1,10 @@
> > +#!/bin/bash
> > +# SPDX-License-Identifier: GPL-2.0
> > +
> > +set -o nounset
> > +
> > +DTB_DIR=$1
> > +DTB_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')
> > +DTB_INFO="From Linux $KERNELRELEASE by $DTB_COMPILE_BY the $(date).\0"
> 
> I would remove the filler words "From", "by", "the", and the trailing
> period ('.').
> 
> <bikeshed>
> You might consider using a format more like the Linux
> kernel version line, which puts parenthesis around the
> compiled by info.
> </bikeshed>
> 
> -Frank
> 
> > +
> > +printf "$DTB_INFO" > "$DTB_DIR/dtb-build.txt"
> > 
> 

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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Re: [RFC PATCH v2 1/4] scripts: Add script to generate dtb build information

[Frank Rowand]

On 2/23/20 3:59 PM, David Gibson wrote:
> On Fri, Feb 21, 2020 at 11:52:34AM -0600, Frank Rowand wrote:
>> On 2/21/20 10:14 AM, Alexandre Torgue wrote:
>>> This commit adds a new script to create a file (in dts file directory) with
>>> some information (date, Linux version, user). This file could then be used
>>> to populate "build-info" property in every dts file that would use this
>>> build information:
>>>
>>> Example:
>>>
>>> / {
>>> 	...
>>> 	build-info = /incbin/("dtb-build.txt");
>>
>> s/.txt/.dtsi/
> 
> I don't think that makes sense.  This is an /incbin/ not an /include/
> so the text file is *not* dts information.

You are right, thanks for catching that.

-Frank

> 
>> and same wherever the file name is used.
>>
>>
>>> 	...
>>> };
>>>
>>> Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>
>>>
>>> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
>>> index bae62549e3d2..a5af84ef4ffc 100644
>>> --- a/scripts/Makefile.lib
>>> +++ b/scripts/Makefile.lib
>>> @@ -246,6 +246,7 @@ quiet_cmd_gzip = GZIP    $@
>>>  # DTC
>>>  # ---------------------------------------------------------------------------
>>>  DTC ?= $(objtree)/scripts/dtc/dtc
>>> +DTB_GEN_INFO ?= $(objtree)/scripts/gen_dtb_build_info.sh
>>>  
>>>  # Disable noisy checks by default
>>>  ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
>>> @@ -286,6 +287,7 @@ $(obj)/%.dtb.S: $(obj)/%.dtb FORCE
>>>  
>>>  quiet_cmd_dtc = DTC     $@
>>>  cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
>>> +	$(DTB_GEN_INFO) $(src) ; \
>>>  	$(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
>>>  	$(DTC) -O $(2) -o $@ -b 0 \
>>>  		$(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
>>> diff --git a/scripts/gen_dtb_build_info.sh b/scripts/gen_dtb_build_info.sh
>>> new file mode 100755
>>> index 000000000000..0cd8bd98e410
>>> --- /dev/null
>>> +++ b/scripts/gen_dtb_build_info.sh
>>> @@ -0,0 +1,10 @@
>>> +#!/bin/bash
>>> +# SPDX-License-Identifier: GPL-2.0
>>> +
>>> +set -o nounset
>>> +
>>> +DTB_DIR=$1
>>> +DTB_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')
>>> +DTB_INFO="From Linux $KERNELRELEASE by $DTB_COMPILE_BY the $(date).\0"
>>
>> I would remove the filler words "From", "by", "the", and the trailing
>> period ('.').
>>
>> <bikeshed>
>> You might consider using a format more like the Linux
>> kernel version line, which puts parenthesis around the
>> compiled by info.
>> </bikeshed>
>>
>> -Frank
>>
>>> +
>>> +printf "$DTB_INFO" > "$DTB_DIR/dtb-build.txt"
>>>
>>
> 

Re: [RFC PATCH v2 4/4] script: make automatic dtb build info generation

[Rob Herring]

On Fri, Feb 21, 2020 at 05:14:18PM +0100, Alexandre Torgue wrote:
> Append each "xxx.dtb.dts.tmp" file with "build-info" entry during dtb
> build. It allows to get build information (date, source version, ...)
> for each device tree without modify them manually.
> 
> Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>
> 
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index a5af84ef4ffc..f084e78267b2 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -289,6 +289,7 @@ quiet_cmd_dtc = DTC     $@
>  cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
>  	$(DTB_GEN_INFO) $(src) ; \

We regenerate this for every dtb?

>  	$(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
> +	$(DTB_GEN_INFO) $(src) $(dtc-tmp) ; \
>  	$(DTC) -O $(2) -o $@ -b 0 \
>  		$(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
>  		-d $(depfile).dtc.tmp $(dtc-tmp) ; \
> diff --git a/scripts/gen_dtb_build_info.sh b/scripts/gen_dtb_build_info.sh
> index 0cd8bd98e410..72f31e386787 100755
> --- a/scripts/gen_dtb_build_info.sh
> +++ b/scripts/gen_dtb_build_info.sh
> @@ -6,5 +6,7 @@ set -o nounset
>  DTB_DIR=$1
>  DTB_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')

Use LINUX_COMPILE_BY #define

>  DTB_INFO="From Linux $KERNELRELEASE by $DTB_COMPILE_BY the $(date).\0"

I'd use UTS_RELEASE and UTS_VERSION defines here.

> +DTS_FILE=$2
>  
> -printf "$DTB_INFO" > "$DTB_DIR/dtb-build.txt"
> +printf "$DTB_INFO" > "arch/arm/boot/dts/dtb-build.txt"

Obviously, hardcoding this is not right. You probably need to prepend 
with $(obj) so this works for out of tree builds too.

> +echo "&{/} {build-info = /incbin/(\"dtb-build.txt\");};" >> $DTS_FILE

You could commit the .dtsi file using the above defines and then just 
add a #include of it here. Then we'd get dependency tracking for free.

Rob

Re: [RFC PATCH v2 2/4] of: fdt: print dtb build information

[Rob Herring]

On Fri, Feb 21, 2020 at 05:14:16PM +0100, Alexandre Torgue wrote:
> This commit prints out DTB build information (build time, dts source
> version used, ...) if "Build-info" property exists in DTB root node.

/Build/build/

> 
> Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>
> 
> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> index 2cdf64d2456f..aa5989039746 100644
> --- a/drivers/of/fdt.c
> +++ b/drivers/of/fdt.c
> @@ -1224,9 +1224,18 @@ bool __init early_init_dt_scan(void *params)
>   */
>  void __init unflatten_device_tree(void)
>  {
> +	const char *build_info;
> +	unsigned long dt_root;
> +
>  	__unflatten_device_tree(initial_boot_params, NULL, &of_root,
>  				early_init_dt_alloc_memory_arch, false);
>  
> +	/* If available, provide dtb build information */
> +	dt_root = of_get_flat_dt_root();
> +	build_info = of_get_flat_dt_prop(dt_root, "build-info", NULL);

We just unflattened the tree, why are we using the flat dt functions?

> +	if (build_info)
> +		pr_info("%s\n", build_info);
> +
>  	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
>  	of_alias_scan(early_init_dt_alloc_memory_arch);
>  
> -- 
> 2.17.1
> 

Re: [RFC PATCH v2 0/4] Add device tree build information

[Frank Rowand]

Hi Alexandred,

Ping.

-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
> 
>>
>> 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
>>
> 
> 

Re: [RFC PATCH v2 1/4] scripts: Add script to generate dtb build information

[Alexandre Torgue]

On 2/21/20 8:38 PM, Rob Herring wrote:
> On Fri, Feb 21, 2020 at 11:52 AM Frank Rowand <frowand.list@gmail.com> wrote:
>>
>> On 2/21/20 10:14 AM, Alexandre Torgue wrote:
>>> This commit adds a new script to create a file (in dts file directory) with
>>> some information (date, Linux version, user). This file could then be used
>>> to populate "build-info" property in every dts file that would use this
>>> build information:
>>>
>>> Example:
>>>
>>> / {
>>>        ...
>>>        build-info = /incbin/("dtb-build.txt");
>>
>> s/.txt/.dtsi/
>>
>> and same wherever the file name is used.
>>
>>
>>>        ...
>>> };
>>>
>>> Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>
>>>
>>> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
>>> index bae62549e3d2..a5af84ef4ffc 100644
>>> --- a/scripts/Makefile.lib
>>> +++ b/scripts/Makefile.lib
>>> @@ -246,6 +246,7 @@ quiet_cmd_gzip = GZIP    $@
>>>   # DTC
>>>   # ---------------------------------------------------------------------------
>>>   DTC ?= $(objtree)/scripts/dtc/dtc
>>> +DTB_GEN_INFO ?= $(objtree)/scripts/gen_dtb_build_info.sh
>>>
>>>   # Disable noisy checks by default
>>>   ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
>>> @@ -286,6 +287,7 @@ $(obj)/%.dtb.S: $(obj)/%.dtb FORCE
>>>
>>>   quiet_cmd_dtc = DTC     $@
>>>   cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
>>> +     $(DTB_GEN_INFO) $(src) ; \
>>>        $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
>>>        $(DTC) -O $(2) -o $@ -b 0 \
>>>                $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
>>> diff --git a/scripts/gen_dtb_build_info.sh b/scripts/gen_dtb_build_info.sh
>>> new file mode 100755
>>> index 000000000000..0cd8bd98e410
>>> --- /dev/null
>>> +++ b/scripts/gen_dtb_build_info.sh
>>> @@ -0,0 +1,10 @@
>>> +#!/bin/bash
>>> +# SPDX-License-Identifier: GPL-2.0
>>> +
>>> +set -o nounset
>>> +
>>> +DTB_DIR=$1
>>> +DTB_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')
>>> +DTB_INFO="From Linux $KERNELRELEASE by $DTB_COMPILE_BY the $(date).\0"
>>
>> I would remove the filler words "From", "by", "the", and the trailing
>> period ('.').
>>
>> <bikeshed>
>> You might consider using a format more like the Linux
>> kernel version line, which puts parenthesis around the
>> compiled by info.
> 
> IMO, we should use exactly the Linux kernel version line. Or exactly
> the u-boot version line when built in u-boot.

I agree to keep the same format than Linux banner. But does it make 
sense to keep uts version, config flags ?

regards
Alex

> 
> Rob
> 

Re: [RFC PATCH v2 0/4] Add device tree build information

[Alexandre Torgue]

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
>>>
>>
>>
> 

Re: [RFC PATCH v2 0/4] Add device tree build information

[Steve McIntyre]

Hi Alexandre,

On Mon, Mar 02, 2020 at 01:55:55PM +0100, Alexandre Torgue wrote:
>On 2/28/20 6:47 PM, Frank Rowand wrote:
>> > 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.

Have you made any progress on this please?

Cheers,
-- 
Steve McIntyre                                steve.mcintyre@linaro.org
<http://www.linaro.org/> Linaro.org | Open source software for ARM SoCs

Re: [RFC PATCH v2 0/4] Add device tree build information

[Alexandre Torgue]

Hi Steeve

On 3/31/20 3:03 AM, Steve McIntyre wrote:
> Hi Alexandre,
> 
> On Mon, Mar 02, 2020 at 01:55:55PM +0100, Alexandre Torgue wrote:
>> On 2/28/20 6:47 PM, Frank Rowand wrote:
>>>> 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.
> 
> Have you made any progress on this please?

Unfortunately no. I cook something locally but not yet upstream-able.
Due to project issue I didn't find time to work on it. I think (I hope) 
to be less busy next week and so I'll restart it.

regards
alex

> 
> Cheers,
> 

[RFC PATCH v2 2/4] of: fdt: print dtb build information

[Alexandre Torgue]

This commit prints out DTB build information (build time, dts source
version used, ...) if "Build-info" property exists in DTB root node.

Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 2cdf64d2456f..aa5989039746 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -1224,9 +1224,18 @@ bool __init early_init_dt_scan(void *params)
  */
 void __init unflatten_device_tree(void)
 {
+	const char *build_info;
+	unsigned long dt_root;
+
 	__unflatten_device_tree(initial_boot_params, NULL, &of_root,
 				early_init_dt_alloc_memory_arch, false);
 
+	/* If available, provide dtb build information */
+	dt_root = of_get_flat_dt_root();
+	build_info = of_get_flat_dt_prop(dt_root, "build-info", NULL);
+	if (build_info)
+		pr_info("%s\n", build_info);
+
 	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
 	of_alias_scan(early_init_dt_alloc_memory_arch);
 
-- 
2.17.1