Management Component Transport Protocol (MCTP) support for Rust

This workspace repository contains a set of crates providing MCTP support, primarily for use in embedded applications.

Component Crates

• mctp implements base type and trait definitions.

• mctp-linux implements a transport implementation, using the Linux kernel MCTP sockets support for message send/receive

• pldm provides Platform Level Data Model (PLDM) base definitions on top of the generic MCTP support

• pldm-fw uses the pldm base definitions to implement the PLDM for Firmware Update protocol as a library. It include a Firmware Device (fd) responder that can run on embedded devices with no_std, and an Update Agent (ua) for std platforms.

• pldm-fw-cli is a command-line PLDM Firmware Update utility. This targets mctp-linux though could be adapted to any implementation of the mctp crate traits.

• mctp-estack is a MCTP stack suitable for embedded devices, running no_std with fixed allocations. The stack handles message fragmentation/reassembly and tag tracking. The crate's Router can be used by async MCTP applications to interface with multiple transport ports, and handles MCTP bridging. It includes built-in MCTP transport handling for I2C, USB, and serial.

  mctp-estack includes a minimal MCTP control protocol implementation.

• mctp-usb-embassy is a MCTP over USB transport for embassy-usb.

• standalone is a mctp trait implementation that includes its own mctp-estack instance, allowing running a standalone MCTP-over-serial stack against a Linux TTY (or any other pipe device). This can be used for example with QEMU.

API Documentation

mctp mctp-linux pldm pldm-fw mctp-estack mctp-usb-embassy

Examples

There's a small example MCTP requester in mctp-linux/examples:

    // Create a new endpoint using the linux socket support
    let mut ep = MctpLinuxReq::new(EID, None)?;

    // for subsequent use of `ep`, we're just interacting with the
    // mctp::ReqChannel trait, which is independent of the socket support

    // Get Endpoint ID message: command 0x02, no data. Allow the MCTP stack
    // to allocate an owned tag.
    let tx_buf = vec![0x02u8];
    ep.send(MCTP_TYPE_CONTROL, &tx_buf)?;

    // Receive a response. We create a 16-byte vec to read into; ep.recv()
    // will return the sub-slice containing just the response data.
    let mut rx_buf = vec![0u8; 16];
    let (typ, ic, rx_buf) = ep.recv(&mut rx_buf)?;

There are also some MCTP over serial examples in standalone/examples.