Re: [PATCH] kbuild: add target to build a cpio containing modules

[Ahmad Fatoum]

Hi Nathan,

On 11/20/25 7:39 AM, Nathan Chancellor wrote:
> On Sat, Nov 15, 2025 at 03:21:51PM +0100, Ahmad Fatoum wrote:
>> From: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
>> +modules-install: FORCE
>> +	$(Q)$(MAKE) -f $(srctree)/Makefile
>> +	$(Q)rm -rf $@
>> +	$(Q)$(MAKE) -f $(srctree)/Makefile INSTALL_MOD_PATH=$@ modules_install
>> +
>> +quiet_cmd_cpio = CPIO    $@
>> +      cmd_cpio = $(srctree)/usr/gen_initramfs.sh $< > $@
>> +
>> +modules-$(KERNELRELEASE)-$(ARCH).cpio: modules-install
>> +	$(Q)$(MAKE) -f $(srctree)/Makefile $(build)=usr cpio-data= usr/gen_init_cpio
> 
> This seems like a bit of a hack to generate gen_init_cpio this way but I
> am not sure it is worth moving usr/gen_init_cpio.c and
> usr/gen_initramfs.sh elsewhere (scripts?) to make it a most accessible
> hostprog right now... Nicolas, do you have any opinions on this?

After incorporating Thomas' feedback, this is simplified to:

  $(Q)$(MAKE) $(build)=usr usr/gen_init_cpio

which looks much better.

>> +	$(call cmd,cpio)
>> +
>> +PHONY += cpio-modules-pkg
>> +cpio-modules-pkg: modules-$(KERNELRELEASE)-$(ARCH).cpio
> 
> I think it would make a little more sense (and match the style of the
> perf package targets as well) to name this target modules-cpio-pkg.

It currently matches the style of the tar packages, which start with
tar-, but I can follow the perf- order. Makes more sense if it's
extended to support compressed cpios in future too.

Cheers,
Ahmad

> 
>> +	@:
>> +
>>  # perf-tar*-src-pkg - generate a source tarball with perf source
>>  # ---------------------------------------------------------------------------
>>  
>> @@ -245,6 +261,7 @@ help:
>>  	@echo '  tarbz2-pkg          - Build the kernel as a bzip2 compressed tarball'
>>  	@echo '  tarxz-pkg           - Build the kernel as a xz compressed tarball'
>>  	@echo '  tarzst-pkg          - Build the kernel as a zstd compressed tarball'
>> +	@echo '  cpio-modules-pkg    - Build the kernel modules as cpio archive'
>>  	@echo '  perf-tar-src-pkg    - Build the perf source tarball with no compression'
>>  	@echo '  perf-targz-src-pkg  - Build the perf source tarball with gzip compression'
>>  	@echo '  perf-tarbz2-src-pkg - Build the perf source tarball with bz2 compression'
>>
>> ---
>> base-commit: e9a6fb0bcdd7609be6969112f3fbfcce3b1d4a7c
>> change-id: 20251115-cpio-modules-pkg-70d85a69892b
>>
>> Best regards,
>> -- 
>> Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
>>
> 

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