Grab this tarball, extract it, and ./run-qemu.sh. It's a simple linux+initramfs image that boots to a shell prompt.
https://landley.net/bin/mkroot/latest/or1k.tgz QEMU 7.0.0 ran that linux-or1k image, but newer qemu does not. I besected the issue to qemu commit 0a923be2f642, and it's still broken in current tip of tree. Rebuilding the image with current linux-git doesn't seem to make a difference? Either way I get serial output with old qemu and don't with current qemu. Rob P.S. Reproduction sequence for the tarball available upon request, kernel config is in the docs/ directory, userspace is just a toybox mkroot build but "not getting kernel boot messages" happens way before userspace gets a vote.
