BFE EngineeringandClaude Fable 5
13b7d063a2
Phase 4+5 of the device sim: - Display + touch verified end-to-end: virtio-gpu at 720x720 (fbdev emulation) renders the real WardenOS dashboard from the static LVGL fbdev+evdev UI build (flare-edge qemu-vm-support tools/build-ui-vm.sh); QMP input-send-event taps the Metrics tab and qemu/tests/ui-shot.sh asserts the repaint from screendumps. Two load-bearing QEMU flags found and documented: -global virtio-mmio.force-legacy=false (gpu/input are VERSION_1-only) and the 200ms press hold (an instantaneous press+release lands inside one LVGL indev poll and never clicks). - qemu/tests/qmp.py: minimal QMP client (screendump, tap, quit). - stage-2 init starts warden-ui when present and fb0 exists. - docs/decisions/0006-qemu-device-sim.md: virt-not-custom-board, the enters-at-kernel boundary, fragment policy, naming, consequences. - docs/architecture.md: new section 7 (device emulation), order-of-work item 7; modbus cross-reference to the bridge. - qemu/README.md: emulated-vs-not table, scenarios, gotchas, host/runner requirements. docs/ci-cd.md: runner needs one-time qemu-system-arm install (fail-closed smoke until then, [maintainer]-gated). Repo README updated. Final sweep on this commit: shellcheck clean, bridge 7/7 tests, boot smoke PASS, portal scenario PASS (check-in + fw pull + signed .wfw download), ui-shot PASS (touch navigates to Metrics) — all under the final flags. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_018HUayid7W5w7jBdb9Rrj1K
102 lines
5.3 KiB
Markdown
102 lines
5.3 KiB
Markdown
# qemu/ — the WardenOS device simulator
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A QEMU virtual machine that boots the real forward-ported kernel (`build/` +
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`patches/`) and real userspace, so the *device* — init, daemons, networking,
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OTA, watchdog, display — can be tested off-hardware. The third simulator in
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the stack, deliberately not named "sim":
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- `lvglsim` (flare-edge) — SDL desktop build of the UI. Rendering only.
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- `sim/` (this repo) — register-level Rust models of RV1106 blocks behind
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driver seams.
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- `qemu/` (this) — the whole machine above the kernel entry point, running
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the real binaries.
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Decision record: `docs/decisions/0006-qemu-device-sim.md`.
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## The boundary (read this before trusting a green run)
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There is no RV1106 machine model in QEMU and everything below the kernel is
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closed rkbin blobs plus mask ROM, so the VM **enters at `-kernel zImage`** on
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`-M virt,highmem=off` (single Cortex-A7, 256M — the RV1106G3's shape).
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| Emulated / substituted | Not emulated (stays bench / `sim/` territory) |
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| Kernel boot, init ordering, switch_root | BootROM, idblock/DDR-init, SPL, U-Boot |
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| A/B *outcome* (`warden.slot=` cmdline) | Real BCB A/B selection, bootcount auto-revert |
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| Storage: virtio-blk with the device's exact `blkdevparts=` layout + `/dev/block/by-name/` contract | eMMC controller itself |
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| Network: virtio-net (slirp, hostfwd 22/80/28443) | GMAC, AIC8800 wifi, usb0 gadget |
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| Display: virtio-gpu 720x720 via fbdev emulation | VOP/RGB666 pipeline, CH32V003 panel init, RGA blits |
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| Touch: virtio-tablet (QMP `input-send-event`) | GT911 on I2C3 |
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| Watchdog: i6300esb (PCI), `-action watchdog=reset` | DW watchdog @0xff5a0000, HPMCU supervisor |
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| RS485: pci-serial chardev bridged to `sim/`'s `ModbusSlave` | Real UART4 timing/electrical behavior |
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| RTC: PL031 (`--rtc` reproduces the no-RTC 2021-clock incident class) | The unpopulated backup-cell reality |
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**"Boots/works under emulation" is never evidence of "works on silicon."**
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The VM narrows which claims need a panel; on-device claims still need
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on-device evidence. Conversely, the VM is the first environment that runs
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production binaries on a non-RV1106 memory map — it found flare-edge #106
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(fatal SIGBUS in flared's HPMCU probe) and #107 (Y2038 time_t truncation)
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on its first two boots of real userspace.
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Documented guest deviations from production, set by stage-2 init:
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`WARDEN_FLARE_INSECURE=1` (the desk mock portal is plain HTTP) and
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`WARDEN_HPMCU=0` (no mailbox SRAM on virt; flared >= flare-edge#106 fix
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required, or the daemon dies of SIGBUS).
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## Quick start
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```sh
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# 1. kernel: canonical build boots the VM as-is; the fragment variant adds
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# the scenario devices (PCI serial, watchdog, WireGuard, virtio-gpu/input)
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WORK=$HOME/kbuild-out CROSS_COMPILE=arm-linux-gnueabihf- \
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WARDEN_KCONFIG_FRAGMENT=qemu/configs/virt.fragment bash build/build-kernel.sh
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# 2. initramfs (sha256-pinned static busybox + qemu/rootfs/) and A/B disk
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bash qemu/mkinitramfs.sh
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bash qemu/mkimage.sh # options: --portal-url --state K=V --fw-version
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# 3. run (see run.sh header for all flags)
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bash qemu/run.sh --kernel $HOME/kbuild-out/linux-6.18.46/arch/arm/boot/zImage --shell
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```
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Payload: drop static musl armv7 binaries into `qemu/payload/` (see its
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README) — `warden-flared`, `warden-modbus`, and `warden-ui` (the LVGL
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fbdev+evdev build from flare-edge `tools/build-ui-vm.sh`) are started by
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stage-2 init when present.
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## Scenario tests (`qemu/tests/`)
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- `boot-smoke.sh <zImage>` — sentinel-asserting boot; runs in CI inside the
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kernel-build job.
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- `portal-scenario.sh <zImage>` (needs `FLARE_EDGE=<checkout>`) — the real
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flared in the VM against the desk mock portal: authenticated check-in,
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firmware desired-state pull, and download of a real signed tier-1 `.wfw`
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offer. Verify/stage/APPLYING run as a dry run (no `WARDEN_FW_ALLOW_APPLY`);
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flipping it on inside the VM is the documented stretch — apply writes
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`/dev/block/by-name/rootfs_b` inside disk.img, then `--slot _b` boots it.
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- `ui-shot.sh <zImage>` — display+touch: boots headless with virtio-gpu,
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QMP-screendumps the 720x720 UI, taps the Metrics tab via `input-send-event`
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(a 200 ms hold — an instantaneous press+release lands inside one LVGL poll
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and never clicks), and asserts the frame changed. `qmp.py` is the tiny QMP
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client.
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- Watchdog: `run.sh --watchdog`, arm `/dev/watchdog` in the guest, don't pet —
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the VM resets ~30 s later (verified). Do NOT combine with a flared payload
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expecting survival: flared pets only while the UI heartbeat is fresh.
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## Gotchas that cost time (so they cost it once)
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- AF_UNIX socket paths cap at ~108 chars — keep `--rs485`/`--qmp` paths short.
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- A serial port that is closed discards incoming bytes: hold ONE fd open
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across write and read when scripting the guest side of the RS485 bridge.
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- `highmem=off` and `-global virtio-mmio.force-legacy=false` are load-bearing
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(32-bit ECAM reach; virtio-1-only gpu/input) — both live in run.sh.
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- Never pass `earlyprintk`: DEBUG_UART_PHYS is the RV1106's 0xff4c0000.
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## Host requirements
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`qemu-system-arm` (Debian 13 ships QEMU 10), `curl`, `cpio`, `mkfs.ext4`,
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`gcc-arm-linux-gnueabihf` (kernel build), `python3` (+`cryptography` for the
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portal scenario's `.wfw` signing). CI: the hosted `qemu-tools` job builds the
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tooling; the boot smoke runs on the self-hosted kernel-build runner, which
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needs a one-time `apt-get install qemu-system-arm` (see docs/ci-cd.md).
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