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gerrit.openbmc.org / openbmc / libcper / 2d4d3b65396596d8939bacaea54ed529530362f9
commit2d4d3b65396596d8939bacaea54ed529530362f9[log] [tgz]
authorEd Tanous <ed@tanous.net>Tue Mar 11 10:34:29 2025 -0700
committerEd Tanous <ed@tanous.net>Tue Mar 25 19:41:20 2025 +0000
treeba832de52d9aa8daced20a529e544a577a4b6428
parent50b966f7afa31fe39fda70e10eb9139cce39e025 [diff]
Fix randomizer

Relying on the system randomizer for unit tests leads to cases where we
don't get deterministic results, which causes inconsistent results.
These random results don't need to be secure, so reimplement as a simple
linear feedback shift register[1].  This makes our unit tests now
produce the same output every time we call generate.

Note, this change showed a weakness in our testing, where timestamps
relied on different rules for ir->cper versus cper->ir.  hour 24 should
be allowed.

[1] https://en.wikipedia.org/wiki/Linear-feedback_shift_register

Change-Id: I0756b086c8ea5fb934e450f5d33e3ae0036868b3
Signed-off-by: Ed Tanous <ed@tanous.net>
17 files changed
tree: ba832de52d9aa8daced20a529e544a577a4b6428
  1. cli-app/
  2. docs/
  3. examples/
  4. generator/
  5. include/
  6. sections/
  7. specification/
  8. subprojects/
  9. tests/
  10. .clang-format
  11. .clang-tidy
  12. .gitignore
  13. base64.c
  14. common-utils.c
  15. cper-parse.c
  16. cper-parse.i
  17. cper-utils.c
  18. Cper.c
  19. ir-parse.c
  20. LICENSE
  21. log.c
  22. meson.build
  23. meson.options
  24. OWNERS
  25. README.md
README.md

CPER JSON Representation & Conversion Library

This repository specifies a structure for representing UEFI CPER records (as described in UEFI Specification Appendix N) in a human-readable JSON format, in addition to a library which can readily convert back and forth between the standard CPER binary format and the specified structured JSON.

Prerequisites

Before building this library and its associated tools, you must have meson (>=1.1.1)

Building

This project uses Meson (>=1.1.1). To build for native architecture, simply run:

meson setup build
ninja -C build

Usage

This project comes with several binaries to help you deal with CPER binary and CPER-JSON. The first of these is cper-convert, which is a command line tool that can be found in build/. With this, you can convert to and from CPER and CPER-JSON through the command line. An example usage scenario is below:

cper-convert to-cper samples/cper-json-test-arm.json --out cper.dump
cper-convert to-json cper.generated.dump

Another tool bundled with this repository is cper-generate, found in build/. This allows you to generate pseudo-random valid CPER records with sections of specified types for testing purposes. An example use of the program is below:

cper-generate --out cper.generated.dump --sections generic ia32x64

Help for both of these tools can be accessed through using the --help flag in isolation.

Finally, a static library containing symbols for converting CPER and CPER-JSON between an intermediate JSON format can be found generated at lib/libcper-parse.a. This contains the following useful library symbols:

json_object* cper_to_ir(FILE* cper_file);
void ir_to_cper(json_object* ir, FILE* out);

Specification

The specification for this project's CPER-JSON format can be found in specification/, defined in both JSON Schema format and also as a LaTeX document. Specification for the CPER binary format can be found in UEFI Specification Appendix N (2021/03/18).

Usage Examples

This library is utilised in a proof of concept displaying CPER communication between a SatMC and OpenBMC board, including a conversion into CPER JSON for logging that utilises this library. You can find information on how to reproduce the prototype at the scripts repository, and example usage of the library itself at the pldm repository.