- profile key extra_drive: optional read-only second virtio-blk so an
overlay can ship guest-side shim libraries (/dev/vdb)
- SENS <name> protocol op: canvas-fed named values (built-in sensors /
buttons) served from PiInstance.sensor_state, pushed by the frontend
via the new pi_sensor_state WS message
- DISP <b64> protocol op: guest display commands forwarded to the
frontend as 'display' events (built-in screens)
- RaspberryPi3Bridge: onDisplay / onGpioPwm callbacks + setSensorState
- SimulatorCanvas hands piFamily boards their Pi bridge in
attachBuiltins (was ESP32-only)
add_reader on the proto FIFO armed epoll but never delivered callbacks
under uvloop when the fd number recycled a just-closed socket fd
(nondeterministic per instance): the guest's GPIO lines sat unread in
the pipe and canvas LEDs stayed dark while serial kept flowing. Pump
the FIFO from a worker thread (select + os.read, like _watch_stderr)
and schedule _handle_gpio_line back onto the loop.
registerPiFamilyKind + ProBoardDef.piFamily route an overlay board through
the existing Raspberry Pi bridge path (WebSocket qemu, VFS panel, boot
terminal); register_pi_board_profile lets the overlay add the matching
PI_CONFIGS entry (cpu/image_set/...) at registration time.
STM32 emulation (open-core, runs via libqemu-arm in the backend worker):
- backend: stm32_lib_manager + stm32_worker (GPIO, USART, I2C/SPI device models
reusing the ESP32 slaves, live sensor updates), arduino_cli STM32 branch,
start_stm32 simulation route.
- frontend: Stm32Bridge + Stm32BluePill(/BlackPill) web components (Wokwi SVGs),
board kinds, Interconnect/boardPinMapping/boardProtocols wiring, example
projects (blink, serial, I2C BMP280/MPU6050/DS1307/SSD1306/weather, 7-seg,
RGB, button, switch, stepper, cross-board interconnect).
- Raspberry Pi 4/5 board elements + thumbnails.
Pro board gating (generic OSS->Pro seam; entitlement logic lives in the overlay):
- lib/proBoardGate.ts: isProBoardKind (STM32 + every QEMU Raspberry Pi),
installBoardGateImpl/boardGateDecision, triggerProUpgradePrompt.
- PRO badge on those boards in the component picker; gate at the picker add +
the run backstop (startBoard).
- backend/app/services/board_access.py: server-side enforcement seam for the
simulation WebSocket; STM32/Pi unavailable -> Pro-framed message.
- desktop: generic QemuDownloadPrompt + Stm32QemuPrompt (download-behind-license,
mirrors the ESP32 prompt).
- .gitignore: never ship libqemu-* binaries in the public image.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Closes the deferred Phase 3.3. Root-causes the Pi 2 "Attempted to
kill init" panic as `mount /dev/vda` failing with EINVAL — Debian
armmp does not have ext4 builtin (only fuseblk in /proc/filesystems).
- qemu_manager: PI_CONFIGS gains raspberry-pi-zero / -1 / -2 entries.
All three use the armmp armhf kernel + Cortex-A7 CPU + the mmio
virtio transport (arm-32 virt PCI fails -75 due to missing reg DT
property). Pi Zero / Pi 1 get the small 1-core / 512 MB profile;
Pi 2 gets 4-core / 1 GB. QEMU command builder branches on cfg.bus
for virtio-blk-pci vs virtio-blk-device (and serial likewise).
- manifest.json: new `raspberry-pi-armhf` image_set wiring three
assets (kernel + initramfs + zstd rootfs).
- Frontend BoardKind gains the three new kinds + an isPiBoardKind()
helper. Replaces the eight scattered `=== 'raspberry-pi-3' ||
=== 'raspberry-pi-4' || === 'raspberry-pi-5'` branches in
useSimulatorStore, Interconnect, loadExample, boardProtocols.
ComponentRegistry gets three new picker entries.
- board-kinds-coverage test: ACCEPTED_UNCOVERED gains the new kinds
(backend boards have no canvas examples).
The matching armhf build-pi-kernel.sh / build-pi-rootfs.sh changes
live in velxio-prod's scripts/ (private overlay) — the upstream
kernel build script only knows about arm64; armhf is built in the
private repo because the assets ship through the license endpoint.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Adds the public extension points the velxio-prod overlay uses to bind
real canvas-side I2C/SPI/UART models (BME280, future MCP23017, etc.)
to a running Pi guest's protocol shims:
- qemu_manager: set_pi_slave_handler(fn) / get_pi_slave_handler() for
pi_attach_slave + pi_detach_slave WebSocket messages. OSS image
leaves the hook unset so the messages are silently dropped.
- simulation route: parses the two new WS message types and forwards
them to the registered handler when present.
- RaspberryPi3Bridge: attachSlave(spec) / detachSlave(spec) frontend
side of the protocol.
- piSlaveScanner: at simulation start walks components + wires,
identifies I2C/SPI/UART peers wired to Pi protocol pins (40-pin
header physical-pin numbering), and emits one attach per
bus/address pair (deduped across SDA+SCL wires).
- RaspberryPiWorkspace: invokes the scanner once the bridge is open,
with retries to ride out the WS-still-connecting race.
- integration test: pi3_bme280_attach.py boots the Pi, pre-attaches a
BME280 via the slave handler, runs a host-side proto loop, runs
guest python smbus2.read_byte_data(0x76, 0xD0) and asserts the
console reads back CHIP=0x60.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Backend: extract per-board config into a PI_CONFIGS dict keyed by
board_type. Pi 3/4/5 share the same arm64 image set (kernel +
initramfs + rootfs) and differ only in QEMU -cpu and -m:
raspberry-pi-3 → cortex-a53 + 1G (BCM2837, ARMv8 64-bit)
raspberry-pi-4 → cortex-a72 + 2G (BCM2711, ARMv8 64-bit)
raspberry-pi-5 → cortex-a76 + 2G (BCM2712, ARMv8 64-bit)
PiInstance now carries board_type so the per-board lookup happens
once at start_instance time. Unknown board_type falls back to
DEFAULT_PI_BOARD ('raspberry-pi-3') instead of erroring out (for
back-compat with older clients).
Pre-warm hook walks every unique image_set in PI_CONFIGS so the
provider only downloads each set once even when several Pi models
are registered.
Frontend:
- BoardKind union gains 'raspberry-pi-4' and 'raspberry-pi-5'.
- BOARD_KIND_LABELS + BOARD_KIND_FQBN entries for both new boards
(FQBN null since they use the Pi VFS + Python toolchain like Pi 3).
- ComponentRegistry inserts two new component metadata entries
cloning the Pi 3 board art with different thumbnail colours.
Tag name reused so the same velxio-raspberry-pi-3 web element
draws the board on the canvas — the 40-pin GPIO layout is
identical across Pi 3/4/5.
- boardProtocols.ts: Pi 3/4/5 share the BCM physical→GPIO table
(PI3_BCM) since the 40-pin header layout is identical.
- loadExample.ts: where 'raspberry-pi-3' is special-cased (VFS
ingest, .cpp vs .ino filename), now matches Pi 3/4/5 alike.
- Interconnect.isPi3Bridge() recognises all three Pi family members
so Arduino↔Pi serial routing keeps working.
- RaspberryPi3Bridge constructor gained a boardKind parameter
defaulting to 'raspberry-pi-3'. The WebSocket 'start_pi' message
now ships the actual board kind so the backend knows which
PI_CONFIGS entry to use.
- useSimulatorStore.addBoard wires bridge construction for all
three Pi family members.
Pi Zero/Pi 1/Pi 2 (armhf) come in Phase 3.3 — separate kernel
package + armhf rootfs build, no change here.
Smoke-tested inside the prod container:
Pi 4 (cortex-a72) → reached agetty login on hvc0
Pi 5 (cortex-a76) → reached agetty login on hvc0
Both show 'aarch64' in uname -m.
QEMU 10's virtserialport on a socket chardev (server=on,wait=off)
silently drops guest→host bytes. Reproduced cleanly: writes from
inside the guest to /dev/vport<N>p<M> succeed (no errno) but the
connected client socket receives 0 bytes. Same bug whether the
client is a single recv loop, multiple threads, TCP or UNIX socket,
or whether QEMU runs as server vs client. virtconsole on the same
socket works fine — only virtserialport is broken.
Workaround: use `pipe` chardev (a pair of named FIFOs created
beforehand by qemu_manager). guest→host through .out flows reliably
in QEMU 10 — verified with manual test: 'echo PIPE_TEST > /dev/vport1p1'
in the guest produces 'PIPE_TEST\n' immediately on the host side.
Changes:
- qemu_manager._boot: allocate a temp basename, mkfifo .in + .out,
pass to QEMU as 'pipe,path=<base>'.
- qemu_manager._connect_gpio: open both FIFOs O_RDWR | O_NONBLOCK on
host side (O_RDWR keeps the FIFOs open even when guest hasn't
opened its side yet), wire .out into asyncio via loop.add_reader.
- qemu_manager._reply_gpio / _send_gpio: write to .in fd via os.write.
- qemu_manager._handle_gpio_line: extended Phase 1 GPIO-only parser
into a full Phase 2 mux: GPIO/GPIO_SETUP/GPIO_IN/PWM_*/I2C/SPI/UART
with appropriate replies.
- qemu_manager._shutdown: close FDs + unlink the FIFOs.
- manifest.json: bump raspberry-pi-3-virt rootfs to 2026.05+phase2-shims
(the new rootfs ships the velxio shim Python modules under
/usr/lib/velxio-shims/).
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.
PiTerminal didn't call term.focus() on mount, so xterm.js stayed
passive — onData only fires when the DOM element has focus. Users
saw the boot prompt but their keystrokes went to whatever element
held focus when they clicked Run (canvas, code editor), never
reaching the bridge. Calling focus() right after fit() makes the
prompt receive input the moment it's visible.
The qemu_manager change adds INFO-level logging when serial_input
WebSocket messages reach send_serial_bytes — useful diagnostic for
future Pi3 input problems (proves whether bytes reached the backend
before we look at TTY / kernel / PL011 wiring).
Pi 3 simulator boot through Pi OS systemd graph was unworkable inside
QEMU's raspi3b emulation:
* The PL011 UART at 0x3f201000 enumerates as ttyAMA1 (not ttyAMA0 —
the mini-UART at 0x3f215040 takes ttyAMA0 and fails to probe under
QEMU). After ~9 s of kernel time the boot effectively went silent
on the serial: earlycon was disabled by the normal console init
and the IRQ-driven serial driver loses TX under QEMU's emulation.
* Even with `keep_bootcon`, systemd dependency graph took 2-3 min to
walk inside emulation (network waits, tmpfiles, journald,
hostname/machine-id randomness). Masking 9 boot-blocking units
helped but didn't fix the silent-after-9s problem.
Solution: skip systemd. The SD image is now baked with
`/usr/local/sbin/velxio-init` (a 30-line bash script) and the kernel
cmdline points init= at it. velxio-init mounts /proc /sys /dev /pts
/run /tmp, sets hostname, then loops a passwordless `/bin/bash
--login </dev/ttyAMA1 >/dev/ttyAMA1`. User sees the prompt within
~10 s of clicking Run; Ctrl-D respawns a fresh session.
Cmdline additions:
- `keep_bootcon` — keep earlycon alive after the regular console
registers, so kernel printk continues to reach ttyAMA1.
- `console=ttyAMA1,115200` — the correct PL011, not ttyAMA0.
- `init=/usr/local/sbin/velxio-init` — bypass systemd entirely.
Python, GPIO shim, apt, mount, etc. all work — they don't need
systemd as PID 1, just a populated rootfs + mounted pseudo-fs.
Manifest version bumped to 2026-04-21+velxio-init. Same byte size,
different SHA, so the sidecar-based cache invalidator forces a
re-fetch on every velxio backend the next time it starts.
Two more defects making Pi 3 boot silently:
1. The kernel8.img that ships in the Pi OS armhf boot partition is a
gzip-compressed PE-COFF Image (first 4 bytes 0x1f8b0800). QEMU's
`-kernel` does NOT auto-decompress; it tries to execute the gzip
header as ARM code and the CPU faults immediately. Result: zero
bytes on ttyAMA0, simulator looks dead. Switch the asset_id to a
pre-decompressed kernel (24 MiB raw vs 9.7 MiB gzipped) so QEMU
gets a valid Image to boot.
2. Even with a real kernel, the original cmdline `console=ttyAMA0`
alone wasn't enough — the kernel can't initialise the BCM2837
PL011 UART early enough for `printk` to reach the serial console
under QEMU's bare-metal boot (no Pi firmware to set it up
beforehand). Adding `earlycon=pl011,mmio32,0x3f201000` makes the
kernel program the UART itself in the early boot path.
Verified: boot output starts streaming within 100 ms of QEMU
launch instead of never.
The cmdline also locks the baud rate at 115200 to match the agetty
drop-in created by scripts/configure-pi3-autologin.sh.
User report: clicked Pi 3 board → nothing visible happens. Three
defects, all on the same path:
1. The kernel cmdline carried over from the original pre-OSS-split
code: `quiet init=/bin/sh`. Result: kernel boot messages
suppressed, then dropped straight to bare /bin/sh with no PS1 so
the user sees an empty serial. Removed both. The kernel cmdline
is now just `console=ttyAMA0 root=/dev/mmcblk0p2 rootwait rw
dwc_otg.lpm_enable=0`, which lets systemd start a real
serial-getty@ttyAMA0.service.
2. Pi OS Trixie armhf since Bookworm ships without a default user
(no more pi/raspberry). With cmdline #1 fixed, the user would
land at a login prompt and be stuck. Fix: pre-bake a systemd
drop-in at /etc/systemd/system/serial-getty@ttyAMA0.service.d/
autologin.conf that uses `agetty --autologin root` so the serial
console drops to a root shell on first prompt. The browser
canvas IS the authentication boundary; the SD image is mounted
RO via a qcow2 overlay so per-session edits don't persist.
Edit happens in velxio-prod/scripts/configure-pi3-autologin.sh
(to follow in a separate commit).
3. Architectural: the original cache-hit probe was size-only.
Today's SD image rebake produced a file with identical byte count
but different SHA256 — the cache served stale content for every
request even after a manifest bump. Fix: write a sidecar
`<file>.sha256` after every successful materialise and trust it
on subsequent probes. Manifest SHA bumps invalidate the cache
regardless of size. Two regression tests guard this:
- test_provider_sidecar_invalidates_on_sha_mismatch
- test_provider_missing_sidecar_treats_file_as_invalid
Manifest bumped to version "2026-04-21+autologin" for the SD image
(kernel + DTB unchanged, still 2026-04-21).
Pi 3 simulation had been broken since at least April 2026 (51
fail-events / 24h per docs/PI3_EMULATION_BROKEN.md). Two distinct
defects compounded:
1. qemu_manager.py hard-coded paths for kernel8.img, a device-tree
blob (under a DOS 8.3 short name!), and a 5.4 GiB Raspberry Pi OS
SD image — none of which shipped in the repo or were pulled at
image build.
2. qemu-system-arm + qemu-utils were missing from the Docker image
entirely, so even with the boot files in place QEMU couldn't
launch. Add both to Dockerfile.standalone (~200 MB).
The architecture fix is a new `app.services.boot_images` module:
* Manifest-driven (boot_images/manifest.json, versioned in repo,
declares SHA256 + size for each file, supports an optional
`compressed.{encoding,sha256,size_bytes}` block for assets shipped
as .zst).
* `BootImageProvider` materialises files lazily, atomically (temp +
rename), verifies SHA256 pre- AND post-decompression, caches under
/var/cache/velxio/boot-images, serialises concurrent get() calls
per image set via asyncio.Lock.
* `AssetDownloader` Protocol with two impls:
- `LicenseGatedDownloader` — same flow ESP32 / RISC-V QEMU libs
use (VELXIO_BINARY_BASE_URL + VELXIO_LICENSE_KEY).
- `LocalDirectoryDownloader` — for tests + in-prod use where the
licence-module storage is already on the same filesystem (saves
the loopback HTTP roundtrip on a 1.4 GiB blob).
* `build_downloader_from_env()` picks one — local-dir wins if both
sets of env vars are present, so the prod box short-circuits to
direct disk reads automatically.
* Lifespan hook in qemu_manager.py pre-warms the cache on container
boot so first-time user requests don't pay the 30-60 s download
+ decompress latency.
Adding a future board kind (Pi 4 / Pi 5) is now: upload assets via
upload-binary.sh, append an entry to manifest.json, register a
lifespan pre-warm in the new board's service module. Zero edits to
provider.py / downloader.py.
Manifest entries for raspberry-pi-3:
kernel8.img 9 695 883 bytes (uncompressed)
bcm2710-rpi-3-b.dtb 34 687 bytes (uncompressed)
raspios-trixie-armhf.img 5 729 419 264 bytes raw
/ 1 488 002 803 bytes .zst on wire (zstd -19)
source: 2026-04-21 build from raspberrypi.com
Tests: 21 new unit tests covering manifest parsing, integrity
helpers, both downloaders, and the provider's idempotent /
concurrent / integrity / decompression / warmup paths. In-process
FakeDownloader keeps the suite under 1 s and httpx-free.
Docs: new docs/BOOT_IMAGES.md describes the architecture, on-disk
layout, named-volume operation, and the procedure for adding a new
image set.
- Add VirtualFileSystem component for managing files and directories.
- Integrate useVfsStore for state management of the virtual file system.
- Implement context menu for file operations: New File, New Folder, Rename, Delete.
- Add upload functionality to send files to Raspberry Pi.
- Create default file structure for new Raspberry Pi boards.
- Enhance editor with board-aware features and compile/run orchestration.
- Introduce CompileAllProgress component for tracking compilation status across boards.
- Redesign SerialMonitor to support multiple boards with tabbed interface.
- Establish Raspberry Pi specific workspace with terminal and file system integration.
- Introduced new BoardKind types for Raspberry Pi 3B and updated BoardInstance interface.
- Added BOARD_KIND_LABELS and BOARD_KIND_FQBN mappings for new board types.
- Implemented physical to BCM GPIO mapping for Raspberry Pi 3B in boardPinMapping utility.
- Updated BOARD_COMPONENT_IDS to include Raspberry Pi 3B.
- Enhanced isBoardComponent function to support new board type.
- Modified boardPinToNumber function to handle pin mapping for Raspberry Pi 3B.
- Created a new DocsPage component for project documentation with links to GitHub and Discord.
- Added Arduino sketch for serial communication test between Raspberry Pi and Arduino.
- Implemented avr_runner.js to emulate ATmega328P and bridge serial communication over TCP.
- Developed a Python test script to validate the serial integration between the emulated Raspberry Pi and Arduino.
David Montero Crespo