Re: kernel configs in Debian

[Ryutaroh Matsumoto <ryutaroh@ict.e.titech.ac.jp>]

Hi Alan, thank you for your interest.

> Also look lor /proc/config.gz.  If you have it it's a dump of the
> config options of the running kernel. Whether it gets generated or not
> is itself a config option.

I plan to make the minimal chanages to the config as rebuilding it by

apt-get source linux/sid
cd linux-5.10.28
fakeroot make -f debian/rules.gen setup_arm64_none_arm64
cat >>debian/build/build_arm64_none_arm64/.config <<'EOF'
CONFIG_XEN=n
CONFIG_PARAVIRT=n
EOF
fakeroot debian/rules source
fakeroot make -j 3 -f debian/rules.gen binary-arch_arm64_none_arm64

I expect not having /proc/config.gz as the CONFIG_IKCONFIG is disabled
in the Debian kernel.
I will include diff -u of .config in debian/build/build_arm64_none_arm64
and /usr/src/linux-config-5.10/config.arm64_rt_arm64

As CONFIG_XEN selects CONFIG_PARAVIRT, CONFIG_XEN=n is required
to build a kernel with CONFIG_PARAVIRT=n.

The last build of the above steps failed as ".btf.vmlinux.bin.o: file not recognized: file format not recognized". I am re-trying the build with adding
CONFIG_DEBUG_INFO_BTF=n

As single build takes 6 hours on RPi4B, it can take several days to find correct
steps to build. The above steps seems completely obeying the instructions at

https://www.debian.org/doc/manuals/debian-kernel-handbook/ch-common-tasks.html#s4.2.3
and
https://www.debian.org/doc/manuals/debian-kernel-handbook/ch-common-tasks.html#s4.2.5

Best regards, Ryutaroh