| name | rdk-board-delegate |
| description | Deep S-series (S100/S100P/S600) "big-brain / little-brain" heterogeneous development — MCU1 FreeRTOS firmware (build, remoteproc load, IPC, UART, CAN) AND the Acore/Linux subsystems unique to S boards (hbmem zero-copy shared memory, Acore↔MCU/VDSP/BPU IPC with real-time core pinning, PCIe RC/EP, EtherCAT master, PTP/gPTP, OTA + miniboot, VDSP). Also covers delegating a board task to the OpenClaw agent (board_openclaw_chat / board_openclaw_delegate) with a complete handoff packet. Use whenever the user works on S100/S100P/S600 MCU firmware, real-time joint/motor control, CPU↔MCU IPC, EtherCAT/PTP, PCIe, system upgrade, the vector DSP, or asks how the CPU+BPU+MCU split works. 触发词:S100、S100P、S600、MCU、小脑、大脑、R52、FreeRTOS、固件、remoteproc、烧固件、关节实时控制、电机回路、IPC、共享内存、hbmem、零拷贝、EtherCAT、运动控制主站、PTP、时间同步、PCIe、OTA、miniboot、VDSP、大小脑异构、CAN、OpenClaw、板端委派。Routing — .hbm compile → rdk-device; ready-made models → rdk-model-zoo; ROS/stereo/lidar → rdk-ros; LLM/VLM → rdk-llm-deployment; error-code lookup → rdk-board-knowledge. |
RDK S-Series Heterogeneous Development & Board Delegation
S100/S100P/S600 are not "X-series with more TOPS". They are a single SoC with three heterogeneous compute domains that close the perception→decision→control loop on-chip: CPU (Acore, the "big brain") + BPU (decision) + MCU (the "little brain", hard real-time). The single most important thing to get right is which domain a task belongs to and how the two brains talk — put a millisecond joint loop on the MCU over IPC, never on a Linux RT thread, and never confuse the MCU's remoteproc firmware load with MCU0's fastboot/Xburn flashing.
Scope: RDK S100 / S100P / S600 only (Nash BPU, .hbm artifacts). X3/X5/Ultra have no MCU subsystem and none of this applies. Sources are the official D-Robotics rdk_s_doc repo (docs/07_Advanced_development/05_mcu_development, 02_linux_development, 03_multimedia_development) and developer.d-robotics.cc. Every non-trivial claim was re-verified against those docs.
The three compute domains (the foundation)
| Domain | Hardware | Runs | Typical work | Where you write code |
|---|
| "Big brain" CPU (Acore) | A78AE (S100/S100P 6× @1.5/2.0GHz; S600 18× @2.0GHz) | Ubuntu (S100/S100P 22.04 + Humble, S600 24.04 + Jazzy) | ROS2 nodes, AI orchestration, planning | Most user code lives here |
| "Decision" BPU | Nash — 80 TOPS (S100) / 128 (S100P) / 560 (S600, 4× core) | hbm_runtime | LLM/VLM/detection/segmentation/point cloud | Compile .hbm via hb_compile (see rdk-device) |
| "Little brain" MCU | R52+ (S100 4× / S600 6×, FreeRTOS V10.0.1) | bare FreeRTOS, not Linux | hard real-time joint/motor loops (ms/kHz), IMU pre-proc, CAN | MCU1 firmware (this skill) |
Two facts that catch everyone:
- MCU firmware is not in
apt. You develop MCU1 (open-source business firmware on FreeRTOS), cross-compile a .elf, and load it with Linux remoteproc — no JTAG, no flashing for day-to-day iteration. JTAG / fastboot / Xburn are only for MCU0 (closed-source: boot, power management, OTA).
- CAN on S100/S600 lives in the MCU domain via CANHAL, not Linux SocketCAN. (Only X5 is Linux SocketCAN.)
Decision cheat-sheet — which domain owns the task?
| User's task | Domain | Read |
|---|
| Joint / motor PID loop, kHz control, IMU pre-processing | MCU1 firmware | mcu-development.md |
| Read/write a sensor over CAN/SPI/I2C/UART in real time | MCU1 (or IpcBox passthrough) | mcu-development.md |
| Zero-copy image/featuremap between camera/ISP/BPU/VDSP | Acore hbmem | s-advanced.md §hbmem |
| Big brain ↔ little brain messaging, real-time core pinning | Acore IPC | s-advanced.md §IPC |
| Multi-axis servo bus master | Acore EtherCAT | s-advanced.md §EtherCAT |
| Multi-sensor / multi-axis time alignment | Acore PTP/gPTP | s-advanced.md §PTP |
| Board-to-board link, S100 as PCIe AI accelerator card | Acore PCIe | s-advanced.md §PCIe |
| Field firmware/system upgrade, bootloader hot-fix | Acore OTA / miniboot | s-advanced.md §OTA |
| Offload image/signal pre-processing from CPU | VDSP | s-advanced.md §VDSP |
| Hand the task to the on-board OpenClaw agent | Delegation packet | Workflow 3 below |
Workflows
Workflow 1 — Develop & load MCU1 firmware (the most common MCU task)
Use when: building/iterating MCU1 firmware, "how do I flash the MCU", "my new firmware won't run".
- Confirm board + version — S100 vs S100P vs S600, and
debug vs release. The build command's argument order differs between S100 and S600 (a classic trap):
- S100:
python build_freertos.py lite matrix B s100 mcu1 gcc <debug|release>
- S600:
python build_freertos.py lite matrix B s600 gcc mcu1 <debug|release> (gcc and mcu1 swapped)
- Build → produces the MCU1
.elf (e.g. S100_MCU_DEBUG.elf, S600_MCU_DEBUG.elf).
- Push & load via remoteproc (no flash, no JTAG):
scp S100_MCU_DEBUG.elf root@<board>:/lib/firmware/
cd /sys/class/remoteproc/remoteproc_mcu0
echo S100_MCU_DEBUG.elf > firmware
echo start > state
- The wfi trap — after
echo stop, you must wait for the system to enter wfi mode before echo start again. Restarting too early reloads firmware over running code in MCU SRAM and the system crashes/runs wild.
- Debug — read MCU log on Acore via
/proc/remoteproc_mcu0 / /proc/remoteproc_mcu1, or over the shared MCU-COM debug UART at 921600 8-N-1 (S100 = Uart4, S600 = Uart8). Check alive/taskcounter/cpuloads sysfs nodes; read crash with cat /sys/devices/platform/soc/soc:mcu_crash/crash.
Full toolchain, build-system files, IPC API, interrupt rules, and S100/S600 diffs: mcu-development.md.
Workflow 2 — Acore-side S-series subsystem (hbmem / IPC / EtherCAT / PTP / PCIe / OTA / VDSP)
Use when: the task is on the Linux side and uses an S-series-only capability.
- Pick the subsystem from the cheat-sheet, then open the matching section of s-advanced.md.
- Check the platform gate — most subsystems cover the whole S family, but a few facts differ by board (verified by the docs'
<DocScope> tags):
- hbmem — S100/S100P + S600 (S600 has its own sample guide; board code at
/app/communication_demo/hbmem_demo/sample_hbmem).
- EtherCAT — Native (
hobot) driver default on S100 V4.0.7+ and S600 V5.1.0+.
- IPC instance ranges differ: S100 Acore
[0-34] (MCU [0-8] usable); S600 Acore [0-63] (MCU [0-15]/[50-53], BPU [32-39]).
- OTA partition table — S100 =
s100-ota-gpt.json, S600 = s600-ota-gpt.json.
- VDSP — S100 single core (
vdsp0); S600 dual core (vdsp0 + vdsp1, VDSP1 is S600-only).
- For real-time control, combine: IPC core-pinning/isolation (§IPC) + PTP time sync (§PTP) + EtherCAT or MCU CAN. This is what makes multi-axis loops deterministic.
Workflow 3 — Delegate a board task to the OpenClaw agent
Use when: calling board_openclaw_chat / board_openclaw_delegate, or a handoff got bounced for being too thin.
A board delegation must carry all five fields — a one-line goal, a thin packet gets rejected. A fill-in-the-blanks template is in assets/templates/openclaw_delegation_packet.md.
| Field | What to write |
|---|
| Goal | One sentence, e.g. "Reload my new MCU1 firmware and confirm IPC works." |
| Background | Why + device state: board (S100/S100P/S600), debug/release, current state (offline/running), TROS distro. |
| Done so far | Commands run with their actual output (ipcbox_set_mode debug, cat .../mcu_version, the echo start result). |
| Analysis | Your hypothesis, e.g. "started before wfi → ran wild" (W1.4), "MCU0/MCU1 double-enabled the same interrupt", "IPC buffer sizes mismatched between the two sides". |
| Expectation | Exactly what you need back: MCU serial log / crash node / a specific sysfs value. |
Worked examples
Example 1 — "我在 S100 上编了新的 MCU 固件，推上去 echo start 之后系统直接挂了 / 跑飞"
This is almost always the wfi trap (W1.4). Ask whether they did echo stop > state, then echo start again without waiting for wfi. Restarting before the system enters wfi reloads firmware over running code in MCU SRAM and crashes the board. Recovery on S-series: you cannot power-cycle MCU1 alone — echo stop > state, let it reach wfi, then echo start. Also confirm the right argument order was used to build (S100 = s100 mcu1 gcc).
Example 2 — "S600 上要做多轴伺服运动控制,EtherCAT 怎么起?跟 S100 一样吗?"
Yes, S600 is covered — but mind the gate: S600 V5.1.0+ defaults to the Native (ec_hobot) EtherCAT driver (S100 is V4.0.7+). The Native driver is mutually exclusive with the hobot_eth_super gmac driver — starting ethercat.service unloads it, the bound port's MAC disappears from ip a, and Native config must use the MAC address (not the interface name). Then sudo ethercat master shows master/slaves/frame stats. Pair with PTP time sync and IPC core-pinning for deterministic multi-axis loops. Details in s-advanced.md §EtherCAT.
Example 3 — "相机出来的图要送进 BPU 推理,怎么不拷贝大块内存?"
Use hbmem zero-copy shared memory (libhbmem / hb_mem_mgr.h). One module's buffer is import-ed into the next thread/process; a consume-count keeps it alive until everyone is done — camera/ISP → BPU input → post-process with no large copies. Use graph_buf for images (planar YUV components are non-contiguous), com_buf for plain featuremaps/audio. hbmem APIs require root. Never mmap a raw physical address — that doesn't bump the reference count and you'll read freed memory. S600 has its own sample at /app/communication_demo/hbmem_demo/sample_hbmem.
Example 4 — "只想更新 bootloader,不想整片重烧整个系统,可以吗?"
Yes — miniboot standalone upgrade works even on non-OTA images and applies on reboot. sudo apt-get install -y hobot-miniboot auto-triggers it, or run sudo rdk-miniboot-update --build release --reboot y. It only touches BAK + AB miniboot partitions (SBL/spl/uboot/bl31/optee/MCU/…), never the Permanent partitions, and cannot upgrade the partition table (table changes need D-Robotics' full-flash tool). Caveat: miniboot upgrade has no built-in auto-rollback — a failed dd or power loss mid-write can brick boot; for safety-critical fields prefer the full system OTA (AB + overlayfs) flow. See s-advanced.md §OTA.
Common pitfalls
| ❌ Don't | ✅ Do |
|---|
| Run a joint/motor loop as a Linux RT thread on S-series | Offload it to MCU1 over IPC for hard real-time |
echo start MCU1 again right after echo stop | Wait for wfi mode first, or the board runs wild |
| Use S100's build arg order on S600 | S100 = s100 mcu1 gcc; S600 = s600 gcc mcu1 (swapped) |
| Treat MCU firmware load like flashing (JTAG/fastboot) | MCU1 = remoteproc .elf; only MCU0 uses fastboot/Xburn |
| Enable the same interrupt on both MCU0 and MCU1 | One interrupt is owned by exactly one core; check the MCU0 reserved list |
| Mismatch IPC channel/buf count/size between the two sides | Acore and MCU configs must match; data/ctrl local↔remote are swapped |
Assume bin/SocketCAN like X-series | S-series = .hbm + hbm_runtime; CAN is MCU-domain CANHAL |
Reuse S100's s100-ota-gpt.json / instance ranges on S600 | S600 = s600-ota-gpt.json, Acore IPC [0-63], dual VDSP, Ubuntu 24.04 |
mmap a raw physical address to share an hbmem buffer | Use import so the consume-count protects it |
Reference map
| Read this | When |
|---|
| mcu-development.md | MCU1 firmware: toolchain, build system, remoteproc/wfi, IPC (Ipc_MDMA_*, IpcBox), UART/CAN, FreeRTOS tasks & interrupt rules, ramdump/crash, S100 vs S600 diffs |
| s-advanced.md | Acore-side S-series subsystems: hbmem zero-copy, Acore IPC + real-time pinning, PCIe RC/EP, EtherCAT-IgH master, PTP/gPTP, OTA + miniboot, VDSP |
| hardware-notes.md | The big-brain/little-brain design rationale, three-domain table, X5-vs-S100 robot pipeline comparison, S100/S100P/S600 specs & buying guide |
assets/templates/openclaw_delegation_packet.md | Fill-in-the-blanks OpenClaw handoff packet (the five required fields) |
