mcumgr_dart 0.3.0

Pure-Dart client for the SMP / MCUmgr protocol (OS, Image/DFU and Filesystem groups) on Zephyr and MCUboot devices. Bring your own transport; no Flutter.

Changelog

0.3.0

Serial and other byte-stream transports no longer have to reimplement Zephyr's framing. Purely additive — no breaking changes, no new dependencies, and the package stays platform-agnostic (the codec is dart:convert + dart:typed_data only, so Web support is unaffected).

• uart_mcumgr encapsulation (UartMcumgrCodec / UartMcumgrDecoder). On BLE the bytes on the characteristic are the SMP frame, so SmpTransport needs nothing else. A byte stream has no packet boundaries, and Zephyr's uart_mcumgr wraps each frame in a length prefix, a CRC-16/XMODEM and base64 lines marked 0x06 0x09 / 0x04 0x14. UartMcumgrCodec.encode() produces those lines and UartMcumgrDecoder.add() recovers whole SMP frames from arbitrary chunk boundaries, leaving a serial or TCP transport with nothing to do but move bytes.

  The decoder is deliberately forgiving, because a device's console log usually shares the pipe: unmarked lines are skipped, and a packet failing its length or CRC check is dropped rather than thrown, so one bad packet cannot wedge the stream. Both are counted in badFrames. encode() emits a single line by default and splits across continuation lines when given a maxLineLength.

  Accumulation is bounded by maxPacketBytes (default 4096). A device that emits a start marker and then never completes the packet — wedged mid-transmission, or a console line that happens to open with the marker bytes — would otherwise grow the buffer without limit. An oversized packet is discarded, counted, and the decoder resumes at the next start marker.

0.2.0

Adds the two remaining read/write management groups from stock Zephyr, both requested in #1. Purely additive — no breaking changes.

• Statistics group (2) — StatMgmt.list() enumerates the groups a device exposes, show() reads one group's counters, showAll() does both. Results come back as StatGroup, whose fields are the entries that decoded as integers and whose rawFields preserves everything as received, so a non-stock stats implementation loses nothing silently. Read-only, because MCUmgr is: there is no command to reset a counter.

• Settings group (3) — SettingsMgmt covers read/write (id 0), delete (1), commit (2) and load/save (3). save({name}) saves one subtree when named and the whole tree when not; an empty name is rejected locally, since Zephyr answers EINVAL for it.

  Values are opaque bytes both ways — the settings subsystem carries no type information, so the API does not invent any. SettingValue offers asInt, asBool and asString for the common cases with their assumptions stated (little-endian, caller-known width), and writeInt / writeBool / writeString encode the same way.

  Truncation is handled explicitly: a device that hits CONFIG_MCUMGR_GRP_SETTINGS_VALUE_LEN returns a short value in an ordinary success response, flagged only by an extra max_size key. SettingValue.truncated surfaces it, and asInt refuses to decode a truncated value — a short integer is a different number, not a partial one.

• Group-specific error names for groups 2 and 3, so SmpException reads settings: key not found (rc=3) rather than group 3 rc=3. Previously only the image group had a table.

• FakeTransport moved to test/fake_transport.dart and is shared by the suite; both new groups are covered without hardware.

0.1.0

Initial release. Extracted from the ProtoCentral OpenView 3 / HealthyPi Move apps as a standalone, pure-Dart library.

• SMP core — SmpMessage (8-byte header + CBOR, SMP v1 rc / v2 err normalisation and error labels), SmpTransport (abstract byte transport), SmpClient (rolling seq request/response matching, fragment reassembly, per-request timeout).
• OS group (OsMgmt, group 0) — echo, mcumgr params, task stat, datetime get/set, reset.
• Image group (ImgMgmt, group 1) — list, chunked/hashed/resumable upload, test, confirm, erase (the DFU flow).
• FS group (FsMgmt, group 8) — stat, download, upload by path.