Re: [ptxdist] [PATCH 1/2] ptxd_make_world_{dtb, dtbo}: add support for device tree overlays

[Michael Riesch <michael.riesch@wolfvision.net>]

Hello Michael,

On 12/9/21 9:53 AM, Michael Olbrich wrote:
> On Thu, Dec 09, 2021 at 08:20:05AM +0100, Michael Riesch wrote:
>> On 12/8/21 9:31 AM, Michael Olbrich wrote:
>>> On Tue, Dec 07, 2021 at 06:30:54PM +0100, Christian Melki wrote:
>>>> I like this take on dtbos!
>>>>
>>>> On 12/7/21 16:39, Michael Riesch wrote:
>>>>> Make ptxd_make_dtb more general and provide suitable wrappers to
>>>>> support the generation of device tree overlays.
>>>>>
>>>>> Signed-off-by: Michael Riesch <michael.riesch@wolfvision.net>
>>>>> ---
>>>>>  rules/post/ptxd_make_world_dtbo.make | 21 +++++++
>>>>>  scripts/lib/ptxd_make_world_dtb.sh   | 82 ++++++++++++++++++++--------
>>>>>  2 files changed, 80 insertions(+), 23 deletions(-)
>>>>>  create mode 100644 rules/post/ptxd_make_world_dtbo.make
>>>>>
>>>>> diff --git a/rules/post/ptxd_make_world_dtbo.make b/rules/post/ptxd_make_world_dtbo.make
>>>>> new file mode 100644
>>>>> index 000000000..61babc653
>>>>> --- /dev/null
>>>>> +++ b/rules/post/ptxd_make_world_dtbo.make
>>>>> @@ -0,0 +1,21 @@
>>>>> +# -*-makefile-*-
>>>>> +#
>>>>> +# Copyright (C) 2020 by Michael Tretter <m.tretter@pengutronix.de>
>>>>> +#
>>>>> +# For further information about the PTXdist project and license conditions
>>>>> +# see the README file.
>>>>> +#
>>>>> +
>>>>> +world/dtbo/env = \
>>>>> +	$(call world/env, $(1)) \
>>>>> +	pkg_dtso_path="$($(1)_DTSO_PATH)" \
>>>>> +	pkg_dtso="$($(1)_DTSO)" \
>>>>> +	pkg_dtbo_dir="$($(1)_DTBO_DIR)" \
>>>>> +	pkg_kernel_src="$($(1)_KERNEL_DIR)" \
>>>
>>> Right, reaching into the source tree of another package is always ugly.
>>> Make sure that <PKG>_DEVPKG is set to 'NO' for the package. It's already
>>> set for the generic kernel package (out-of-tree modules need it as well)
>>> but not for the kernel package template.
>>
>> Could you elaborate a bit on why this is required?
>>
>> What action should be carried out if this variable is not set to 'NO' or
>> must this not happen in the first place?
> 
> If pre-built archives[1] are used are used then the source tree may not be
> available. So if the source/build tree of a package is used by any other
> package then <PKG>_DEVPKG must be set to ensure that the package is always
> built.
> 
> It's a somewhat obscure feature of PTXdist.
> 
> Michael
> 
> [1] https://www.ptxdist.org/doc/daily_work_section.html#using-pre-built-archives
> 

Thanks for the explanation, now I understand why this is necessary.
However, I am still not sure what I can do about it in this patch series.

Can I really change the <PKG>_DEVPKG (e.g., KERNEL_CUSTOM_DEVPKG where
KERNEL_CUSTOM is derived from the kernel template) at the time
world/dtbo is called (from MY_OVERLAY package)? Would it have any effect?

I guess I can output a warning, but as far as I understand the damage is
already done at this point and if there are no kernel sources in
MY_OVERLAY_KERNEL_DIR the dtc command might fail miserably.

How would I determine the kernel package name from the kernel directory
to begin with?

Best regards,
Michael

>>>>> +	pkg_arch="$(GENERIC_KERNEL_ARCH)"
>>>>> +
>>>>> +world/dtbo = \
>>>>> +	$(call world/dtbo/env,$(strip $(1))) \
>>>>> +	ptxd_make_world_dtbo
>>>>> +
>>>>> +# vim: syntax=make
>>>>> diff --git a/scripts/lib/ptxd_make_world_dtb.sh b/scripts/lib/ptxd_make_world_dtb.sh
>>>>> index f5e796b9d..c1ded5ffb 100644
>>>>> --- a/scripts/lib/ptxd_make_world_dtb.sh
>>>>> +++ b/scripts/lib/ptxd_make_world_dtb.sh
>>>>> @@ -9,18 +9,10 @@
>>>>>  ptxd_make_dtb() {
>>>>>      local dtc dts tmp_dts dtb deps tmp_deps
>>>>>  
>>>>> -    if [[ "${dts_dts}" =~ ^/.* ]]; then
>>>>> -	ptxd_bailout "'${dts_dts}' must not be an absolute path!" \
>>>>> -	    "Use <PKG>_DTS_PATH to specify the search path."
>>>>> -    fi
>>>>> -
>>>>> -    if ! ptxd_in_path pkg_dts_path "${dts_dts}"; then
>>>>> -	ptxd_bailout "Device-tree '${dts_dts}' not found in '${pkg_dts_path}'."
>>>>> -    fi
>>>>> -    dts="${ptxd_reply}"
>>>>> -    dtb="${dtb_dir}/$(basename ${dts/%.dts/.dtb})"
>>>>> +    dts="${dtb_source}"
>>>>> +    dtb="${dtb_target}"
>>>>>  
>>>>> -    dtc="${pkg_build_dir}/scripts/dtc/dtc"
>>>>> +    dtc="${dtb_kernel_dir}/scripts/dtc/dtc"
>>>>>      if [ ! -x "${dtc}" ]; then
>>>>>  	dtc=dtc
>>>>>      fi
>>>>> @@ -39,16 +31,16 @@ ptxd_make_dtb() {
>>>>>  	-Wp,-MT,${dtb_deps_target} \
>>>>>  	-nostdinc \
>>>>>  	-I"$(dirname "${dts}")" \
>>>>> -	-I${pkg_dir}/arch/${pkg_arch}/boot/dts \
>>>>> -	-I${pkg_dir}/arch/${pkg_arch}/boot/dts/include \
>>>>> -	-I${pkg_dir}/scripts/dtc/include-prefixes \
>>>>> -	-I${pkg_dir}/drivers/of/testcase-data \
>>>>> -	-I${pkg_dir}/include \
>>>>> +	-I${dtb_kernel_dir}/arch/${pkg_arch}/boot/dts \
>>>>> +	-I${dtb_kernel_dir}/arch/${pkg_arch}/boot/dts/include \
>>>>> +	-I${dtb_kernel_dir}/scripts/dtc/include-prefixes \
>>>>> +	-I${dtb_kernel_dir}/drivers/of/testcase-data \
>>>>> +	-I${dtb_kernel_dir}/include \
>>>>>  	-undef -D__DTS__ -x assembler-with-cpp \
>>>>>  	-o ${tmp_dts} \
>>>>>  	${dts} &&
>>>>>  
>>>>> -    sed -e "\;^ ${pkg_dir}[^ ]*;d" \
>>>>> +    sed -e "\;^ ${dtb_kernel_dir}[^ ]*;d" \
>>>>>  	-e 's;^ \([^ \]*\); $(wildcard \1);' "${tmp_deps}" > "${deps}" &&
>>>>>      # empty line in case all dependencies were removed
>>>>>      echo >> "${deps}" &&
>>>>> @@ -57,9 +49,9 @@ ptxd_make_dtb() {
>>>>>      echo "DTC $(ptxd_print_path "${dtb}")" &&
>>>>>      ptxd_eval \
>>>>>  	"${dtc}" \
>>>>> -	$(ptxd_get_ptxconf PTXCONF_DTC_EXTRA_ARGS) \
>>>>> +	"${dtb_extra_args}" \
>>>>>  	-i "$(dirname "${dts}")" \
>>>>> -	-i "${pkg_dir}/arch/${pkg_arch}/boot/dts" \
>>>>> +	-i "${dtb_kernel_dir}/arch/${pkg_arch}/boot/dts" \
>>>>>  	-d "${tmp_deps}" \
>>>>>  	-I dts -O dtb -b 0 \
>>>>>  	-o "${dtb}" "${tmp_dts}" &&
>>>>> @@ -81,17 +73,61 @@ ptxd_make_dtb() {
>>>>>  export -f ptxd_make_dtb
>>>>>  
>>>>>  
>>>>> +ptxd_make_world_dtbo() {
>>>>> +    local dtb_deps_target dtb_extra_args dtb_kernel_dir dtb_source dtb_target
>>>>> +
>>>>> +    ptxd_make_world_init || break
>>>>> +
>>>>> +    dtb_deps_target="${ptx_state_dir}/${pkg_stamp}"
>>>>> +    dtb_extra_args="-@"
>>>>
>>>> Looks ok. Do we need to do a dtc version check?
>>>> 1.4.4+ I think. Maybe a bit excessive?
>>>
>>> We cannot build dtbos if that's not supported, so a check won't really
>>> help.
>>
>> Ack.
>>
>>>
>>>>> +    dtb_kernel_dir="${pkg_kernel_src}"
>>>>> +    if [ -z $dtb_kernel_dir ]; then
>>>>> +	dtb_kernel_dir="${pkg_dir}"
>>>>> +    fi
>>>
>>>     dtb_kernel_dir="${pkg_kernel_src:-${pkg_dir}}"
>>>
>>> should work. And I think this can be moved to the shared code above. It
>>> works just fine because pkg_kernel_src is never set for the dts case (but
>>> we might want to allow it in the future).
>>
>> Ack.
>>
>>>
>>>>> +
>>>>> +    echo -e "\nBuilding device tree overlays..."
>>>>> +
>>>>> +    for overlay in ${pkg_dtso}; do
>>>>> +	if [[ "${overlay}" =~ ^/.* ]]; then
>>>>> +	    ptxd_bailout "'${overlay}' must not be an absolute path!" \
>>>>> +			 "Use <PKG>_DTSO_PATH to specify the search path."
>>>>> +	fi
>>>>> +
>>>>> +	if ! ptxd_in_path pkg_dtso_path "${overlay}"; then
>>>>> +	    ptxd_bailout "Overlay '${overlay}' not found in '${pkg_dtso_path}'."
>>>>> +	fi
>>>>> +	dtb_source="${ptxd_reply}"
>>>>> +	dtb_target="${pkg_pkg_dir}/${pkg_dtbo_dir}/$(basename ${overlay/%.dts*/.dtbo})"
>>>>> +
>>>>> +	ptxd_make_dtb || break
>>>>> +    done
>>>>> +}
>>>>> +export -f ptxd_make_world_dtbo
>>>>> +
>>>>> +
>>>>>  ptxd_make_world_dtb() {
>>>>> -    local dtb_deps_target dtb_dir
>>>>> +    local dtb_deps_target dtb_extra_args dtb_kernel_dir dtb_source dtb_target
>>>>>  
>>>>>      ptxd_make_world_init || break
>>>>>  
>>>>>      dtb_deps_target="${ptx_state_dir}/${pkg_stamp}"
>>>>> -    dtb_dir="${pkg_pkg_dir}/boot"
>>>>> +    dtb_extra_args="$(ptxd_get_ptxconf PTXCONF_DTC_EXTRA_ARGS)"
>>>>
>>>> Not sure I follow here. Must not the dtb itself be built with -@ for
>>>> symbols if dtbos are used? Does EXTRA_ARGS default to -@ or something?
>>>
>>> I don't know much about dtbos. If -@ is required for the dtb to make dtbos
>>> work, then this should be propagated automatically. Add something to
>>> world/dtb/env, maybe with a noprompt kernel options
>>> KERNEL_DTS_SUPPORT_OVERLAYS or something like that. And select it as
>>> needed.
>>
>> Will change this in v2.
>>
>> Thanks and regards,
>> Michael
>>
>>>
>>>>> +    dtb_kernel_dir="${pkg_dir}"
>>>>> +
>>>>> +    echo -e "\nBuilding device trees..."
>>>>> +
>>>>> +    for tree in ${pkg_dts}; do
>>>
>>> Please keep the dts_dts variable name.
>>>
>>> Michael
>>>
>>>>> +	if [[ "${tree}" =~ ^/.* ]]; then
>>>>> +	    ptxd_bailout "'${tree}' must not be an absolute path!" \
>>>>> +			 "Use <PKG>_DTS_PATH to specify the search path."
>>>>> +	fi
>>>>>  
>>>>> -    echo -e "\nBuilding Device trees..."
>>>>> +	if ! ptxd_in_path pkg_dts_path "${tree}"; then
>>>>> +	    ptxd_bailout "Overlay '${tree}' not found in '${pkg_dts_path}'."
>>>>> +	fi
>>>>> +	dtb_source="${ptxd_reply}"
>>>>> +	dtb_target="${pkg_pkg_dir}/boot/$(basename ${tree/%.dts/.dtb})"
>>>>
>>>> Static output dir path?
>>>>
>>>>>  
>>>>> -    for dts_dts in ${pkg_dts}; do
>>>>>  	ptxd_make_dtb || break
>>>>>      done
>>>>>  }
>>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> ptxdist mailing list
>>>> ptxdist@pengutronix.de
>>>> To unsubscribe, send a mail with subject "unsubscribe" to ptxdist-request@pengutronix.de
>>>>
>>>
>>
>> _______________________________________________
>> ptxdist mailing list
>> ptxdist@pengutronix.de
>> To unsubscribe, send a mail with subject "unsubscribe" to ptxdist-request@pengutronix.de
>>
> 

_______________________________________________
ptxdist mailing list
ptxdist@pengutronix.de
To unsubscribe, send a mail with subject "unsubscribe" to ptxdist-request@pengutronix.de