Re: [PATCH v3 3/5] dpkg: Allow overriding build and host parameters for sbuild and schroot

[Jan Kiszka <jan.kiszka@siemens.com>]

On 16.08.23 16:27, Koch, Stefan (DI PA DCP R&D 3) wrote:
> On Wed, 2023-08-16 at 15:55 +0200, Jan Kiszka wrote:
>> On 16.08.23 14:14, Koch, Stefan (DI PA DCP R&D 3) wrote:
>>> This functionality is initially used for custom linux builds using
>>> the
>>> "-compat" and "-native" multiarch bitbake targets to run additional
>>> target or host specific builds for kbuild scripts and tools.
>>
>> But why does the kernel need these extra params? Why wouldn't it be
>> enough to add arch-specific profile settings for that package so that
>> linux-headers-mykernel-native will compile the kernel only for the
>> native headers and tools?
>>
> 
> Given a image for a arm64 target cross-built on a amd64 host:
> 
> 
> 
> - "bitbake linux" generates with the kbuild-patches:
> linux-headers_arm64.deb
> linux-image_arm64.deb
> linux-kbuild-cross_arm64.deb e. g. containing scripts/fixdep as amd64
> 
> => move to -cross to indicate ARCH mismatch
> 
> *Without* the kbuild-patches there are only 
> linux-headers_arm64.deb e. g. containing scripts/fixdep as amd64 (!!)
> linux-image_arm64.deb
> 
> => *Existing* limitation that ARCH does not match
> 
> 
> 
> - "bitbake linux-kbuild-compat" generates (forcing non-cross QEMU
> build):
> linux-kbuild_arm64.deb e. g. containing scripts/fixdep as arm64
> 
> => scripts utilities can *not* compiled in a cross way
> => this enforces the SBUILD_DIR override to force non-cross QEMU
> 
> Maybe, unsetting ISAR_CROSS_COMPILE for the -compat target makes the
> SBUILD_DIR override needless. It has to be ensured, that no cross-
> compile is used.
> 
> What do you think?
> 
> 
> 
> - "bitbake linux-native" generates:
> linux-kbuild_amd64.deb e. g. containing scripts/fixdep as amd64
> 
> => Optional, only for completeness to have a package matching the
> correct ARCH
> 

I still need to fully wrap around this, but I'm wondering if we are here
really addressing an issue of the sbuild machinery in Isar or rather an
issue of the kernel build recipe that should better be resolved there.

Maybe you can demonstrate the issue also with a simpler package than the
kernel?

Jan

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