Gitiles
Code Review Sign In
gerrit.openbmc.org / openbmc / libmctp / c67605bc9182cde3f9d71df460e7e1c4e87bafc1
commitc67605bc9182cde3f9d71df460e7e1c4e87bafc1[log] [tgz]
authorJeremy Kerr <jk@ozlabs.org>Thu Feb 07 21:52:00 2019 +0800
committerJeremy Kerr <jk@ozlabs.org>Fri Feb 08 10:02:38 2019 +0800
tree47df2704f3a26331246356d62c444a1119aa29fc
parent4cdc200f6effdff45246ad80bd126b3dd18d1e2c [diff]
serial: Don't use packet buffer for escaped tx data

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
1 file changed
tree: 47df2704f3a26331246356d62c444a1119aa29fc
  1. tests/
  2. alloc.c
  3. core.c
  4. libmctp-alloc.h
  5. libmctp-log.h
  6. libmctp-serial.h
  7. libmctp.h
  8. Makefile
  9. Makefile.inc
  10. README.md
  11. serial.c
README.md

libmctp: Implementation of MCTP (DTMF DSP0236)

This library is intended to be a portable implementation of the Management Component Transport Protocol (MCTP), as defined by DMTF standard "DSP0236", plus transport binding specifications.

Currently, the library is is only at prototyping stage. Interfaces will likely change, and are missing lots of components of the standard.

Core API

To initialise the MCTP stack with a single hardware bus:

  • mctp = mctp_init(): Initialise the MCTP core
  • binding = mctp_<binding>_init(): Initialise a hardware binding
  • mctp_register_bus(mctp, binding, eid): Register the hardware binding with the core, using a predefined EID

Then, register a function call to be invoked when a message is received:

  • mctp_set_rx_all(mctp, function): Provide a callback to be invoked when a MCTP message is received

Or transmit a message:

  • mctp_message_tx(mctp, message, len): Transmit a MCTP message

The binding may require you to notify it to receive packets. For example, for the serial binding, the mctp_serial_read() function should be invoked when the file-descriptor for the serial device has data available.

Environment configuration

This library is intended to be portable to be used in a range of environments, but the main targets are:

  • Linux userspace, typically for BMC use-cases
  • Low-level firmware environments

For the latter, we need to support customisation of the functions that libmctp uses (for example, POSIX file IO is not available).

In order to support these, we have a couple of compile-time definitions:

  • MCTP_FILEIO: define if POSIX file io is available, allowing the serial hardware binding to access char devices for IO.

  • MCTP_LOG_: allows selection of a logging backend. Currently available are:

    • MCTP_LOG_STDERR: use fprintf(stderr, ...) for log output

    • MCTP_LOG_SYSLOG: use syslog() for log output

    • MCTP_LOG_CUSTOM: provide your own macro for logging, of the format: #define mctp_prlog(level, fmt, ...) (....)

TODO

  • Message packetisation and reassembly
  • Control messages
  • Message- and packet-buffer pools and preallocation
  • C++ API
  • Non-file-based serial binding