I have posted instructions on how to cross-build and install your own kernel not too long ago, see: https://lists.debian.org/debian-sparc/2025/10/msg00103.html I don't think it's particularly hard.
The upstream kernel sources also have a built-in way to build a Debian kernel package, if you want to make your life a little bit easier: https://kernel-team.pages.debian.net/kernel-handbook/ch-common-tasks.html TL;DR: export ARCH=sparc make -j<jobs> bindeb-pkg A little bit of preparation is still needed: apt install debian-ports-archive-keyring dpkg --add-architecture sparc64 cat >/etc/apt/sources.list.d/debian-ports.sources <<EOF Types: deb URIs: http://ftp.ports.debian.org/debian-ports/ Suites: sid Components: main Signed-By: /usr/share/keyrings/debian-ports-archive-keyring.gpg EOF apt update apt install gcc-sparc64-linux-gnu libdw-dev:native libssl-dev:sparc64