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gerrit.openbmc.org / openbmc / libpldm / 530d1a3a8c83803c42e3f55e9e99ee24074dc3df
commit530d1a3a8c83803c42e3f55e9e99ee24074dc3df[log] [tgz]
authorChau Ly <chaul@amperecomputing.com>Fri Aug 15 05:14:15 2025 +0000
committerChau Ly <chaul@amperecomputing.com>Fri Aug 15 05:14:15 2025 +0000
tree4bf9896f80f6c56ed3b3de97276509328bf4814f
parente98a72fdcc0a4c65d7edb802d403fcff62a3b5cf [diff]
dsp: file: Let some encode APIs accept pointer to payload_length

In order to achieve [1], this commit updates some encoding APIs to
accept the length of the message as an in/out parameter (pointer to
size_t). The APIs are then updated to return the encoded payload length
through this parameter.

The unit tests for these APIs are updated accordingly. The change list
includes:

  - encode_pldm_file_df_open_req()
  - encode_pldm_file_df_close_req()
  - encode_pldm_file_df_heartbeat_req()

[1]: https://github.com/openbmc/libpldm/blob/main/CONTRIBUTING.md?plain=1#L270-L272

Change-Id: Ic81327438190bfa0541333f35e0b52a51010db91
Signed-off-by: Chau Ly <chaul@amperecomputing.com>
4 files changed
tree: 4bf9896f80f6c56ed3b3de97276509328bf4814f
  1. abi/
  2. docs/
  3. evolutions/
  4. include/
  5. instance-db/
  6. scripts/
  7. src/
  8. subprojects/
  9. tests/
  10. tools/
  11. .clang-format
  12. .clang-tidy
  13. CHANGELOG.md
  14. CONTRIBUTING.md
  15. Doxyfile.in
  16. LICENSE
  17. meson.build
  18. meson.options
  19. OWNERS
  20. README.md
README.md

libpldm

This is a library which deals with the encoding and decoding of PLDM messages. It should be possible to use this library by projects other than OpenBMC, and hence certain constraints apply to it:

  • keeping it light weight
  • implementation in C
  • minimal dynamic memory allocations
  • endian-safe
  • no OpenBMC specific dependencies

Source files are named according to the PLDM Type, for eg base.[h/c], fru.[h/c], etc.

Given a PLDM command "foo", the library will provide the following API: For the Requester function:

encode_foo_req() - encode a foo request
decode_foo_resp() - decode a response to foo

For the Responder function:

decode_foo_req() - decode a foo request
encode_foo_resp() - encode a response to foo

The library also provides API to pack and unpack PLDM headers.

To Build

libpldm is configured and built using meson. Python's pip or pipx can be used to install a recent version on your machine:

pipx install meson

Once meson is installed:

meson setup build && meson compile -C build

To run unit tests

meson test -C build

Working with libpldm

Components of the library ABI[^1] (loosely, functions) are separated into three categories:

[^1]: "library API + compiler ABI = library ABI"

  1. Stable
  2. Testing
  3. Deprecated

Applications depending on libpldm should aim to only use functions from the stable category. However, this may not always be possible. What to do when required functions fall into the deprecated or testing categories is discussed in CONTRIBUTING.

Upgrading libpldm

libpldm is maintained with the expectation that users move between successive releases when upgrading. This constraint allows the library to reintroduce types and functions of the same name in subsequent releases in the knowledge that there are no remaining users of previous definitions. While strategies are employed to avoid breaking existing APIs unnecessarily, the library is still to reach maturity, and we must allow for improvements to be made in the design.