Crate tagcore 

Host-side interface to a tag’s firmware monitor, over an ST-LINK.

This is a Rust port of the C++ tagcore tag interface in host/libraries/tagcore: Tag corresponds to Tag (tagclass.*), TagMonitor (the monitor folder) to TagMonitor (tagmonitor.cc, legacy_bittag_rescue.cc) and LinkAdapt (the link folder) to LinkAdapt (linkadapt.*). The layers are the same:

• LinkAdapt finds and opens an ST-LINK with libusb and issues its USB commands: debug-register and memory access, target voltage, nRST.
• TagMonitor runs the monitor protocol over that link. On STM32L4 tags it uses the DebugMonitor exception and the DCRDR mailbox; on STM32U3 tags the shared block at monitor::abi::MONITOR_SHARED_ADDR. Either way an RPC is a serialised proto::Req written into the tag’s buffer and a proto::Ack read back.
• Tag is the thread-safe facade the tools use: one method per request, plus the outcome of the last RPC.

The wire behaviour, timeouts and attach sequences follow the C++ code; see docs/shared/monitor-interface.md for the protocol itself.

Attaching resets the tag

Every attach goes through reset. Attaching to a running tag ends the run it was meant to observe, so never attach just to see what a tag is doing; see docs/bench/verifying-firmware.md.

Other modules

• proto: the protobuf types, generated from proto/ by build.rs, with C++-compatible JSON in and out.
• textformat: protobuf text format laid out as the C++ prints it.
• configshape: which Config fields each tag type supports, from the embedded default-config.json files.

Errors and logging

Requests to the firmware return Result<_, TagError>. The layers below return bool/Option as the C++ does and log the reason through the log facade, so install a logger (RUST_LOG=debug with env_logger shows the attach detail).

The architecture, and where the port deliberately differs from the C++, are described in host/libraries/tagcore-rs/design/architecture.md.

Re-exports

pub use link::LinkAdapt;

pub use link::LinkAdaptStats;

pub use link::UsbDev;

pub use monitor::MemAccess;

pub use monitor::TagMonitor;

pub use monitor::TagMonitorStats;

pub use monitor::TargetFamily;

pub use tag::Tag;

pub use tag::TagError;

Modules

configshape

Which Config fields a tag type supports, as dotted field paths.

link

ST-LINK access over libusb: discovery, attach, and the debug commands the monitor needs.

monitor

The tag monitor protocol over an ST-LINK.

proto

Protobuf messages exchanged with the tag monitor, with reflection.

tag

The tag interface the host tools use: one method per monitor request.

textformat

Protobuf text format as the C++ library prints it.