raspi3b pl011 RX is broken in QEMU 10 + kernel 6.12 — see
project/pi-emulation/decisions.md for the full debugging trail.
This commit lands Phase 1 of the rebuild: switch the QEMU machine
to virt + cortex-a53, boot the velxio kernel/initramfs/rootfs over
virtio-blk-pci, and expose the user shell on /dev/hvc0 via
virtio-serial-pci + virtconsole.
End-to-end smoke verified: boot → agetty autologin → bash prompt →
echo round-trip returns the typed token. Tested inside the prod
container with QEMU 10.0.8 and our cloud-derived kernel 6.12.88.
What changed:
backend/app/services/qemu_manager.py
PI3_IMAGE_SET -> raspberry-pi-3-virt
PI3_KERNEL_NAME / PI3_INITRAMFS_NAME / PI3_ROOTFS_NAME new
QEMU cmd rewritten end-to-end:
-M virt -cpu cortex-a53 -smp 4 -m 1G
-kernel <velxio-kernel-arm64> -initrd <velxio-initramfs-arm64.cpio.gz>
-drive ... -device virtio-blk-pci (NOT virtio-blk-device — mmio
variant left /dev/vda unregistered)
-nic none -display none -monitor none -serial none
-chardev socket... -device virtio-serial-pci -device virtconsole
(user console -> /dev/hvc0)
-chardev socket... -device virtserialport,name=velxio-protocol
(Phase 2 channel -> /dev/vport0p2)
No -dtb (virt generates its own), no -append init=... (kernel runs
our initramfs which then switch_root to rootfs and exec's its
/sbin/init — Alpine OpenRC).
backend/app/services/boot_images/manifest.json
New image set raspberry-pi-3-virt with three assets uploaded via
the existing license-endpoint pipeline. Old raspberry-pi-3 entry
flagged deprecated:true and kept for one release for rollback.
test/pi3_console_boot/test_pi3_console_boot.py
Updated QEMU argv to match qemu_manager exactly. Markers now look
for the Velxio Pi Simulator MOTD + 'login on hvc0' (autologin
proof). Round-trip echo still required to pass.
a7472e3411