Phase 3 of the device sim, all verified on QEMU 10.0.11:
- qemu/rs485-bridge/: std-only crate bridging a QEMU serial chardev (unix
socket) to warden_sim::ModbusSlave — gap-based RTU framing (CRC failures
degrade to real-slave silence), line-protocol control socket for register
seeding and fault injection (drop/exception/clear), bounds-checked so a
scenario typo answers err instead of panicking the bus. 7 unit tests,
bench in the sim_bench pattern. Verified end-to-end: guest master frame
on /dev/ttyS4 (pci-serial) answered from the sim slave, CRC-correct.
- virt machine gains highmem=off: the 32-bit non-LPAE kernel cannot reach
virt's default 40-bit PCIe ECAM (pci-host-generic EOVERFLOW); with it the
full PCI set probes (16550A ttyS0, i6300esb).
- Watchdog scenario verified: guest arms /dev/watchdog, no petting, i6300esb
resets the VM ~30s later (first environment where this arm is testable).
- qemu/tests/portal-scenario.sh: the real static-musl warden-flared inside
the VM against flare-edge's mock portal on the host — authenticated
check-in, firmware desired-state pull, and download of a real signed
tier-1 .wfw offer, asserted from the portal log. Found and filed
flare-edge#106 (fatal SIGBUS in the HPMCU boot-loaded probe on
non-RV1106 memory maps); runs against a flared built from the
qemu-vm-support fix branch.
- stage-2 init: WARDEN_FLARE_INSECURE=1 + WARDEN_HPMCU=0 (documented VM
deviations), firmware-version stamp, newline-terminated state seeds.
- CI: rs485-bridge joins the test loop and bench job; new qemu-tools job
(shellcheck + initramfs + disk image on hosted runners); kernel-build
gains a fail-closed qemu boot-smoke step. All qemu scripts shellcheck-clean.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018HUayid7W5w7jBdb9Rrj1K
