"I am interested in the implementation"

We apologise that at the current stage (it's the early stage, as you can see), there is no sufficient guidance or documents about:
- How the library is implemented
- How to contribute
- How to add new features
- What's the design principles behind the code
- What's the structure of the design in details
Some design considerations:
- The library supports Arm Compiler 5/6, GCC, LLVM and IAR.
- The library supports ALL Cortex-M processors. There should be no problem for working with existing Cortex-M processors, i.e. Cortex-M0/M0+/M1/M3/M4/M7/M23/M33/Star-MC1/M35P/M55/M85. If you find any issue, please feel free to let us know.
- The library is designed with some OOPC (Object-Oriented Programming with ANSI-C) methodologies. And the bottom line is that any methods and tricks adopted in this library should come with no or very little cost.
This library is compliant with C11 standard and uses some widely accepted GCC extensions:
Some of the definitions are written with the support of the Microsoft Extensions in mind ( -fms-extensions ), but the library never depends on it. This means that if programmers enable the support of the Microsoft Extensions in their project, they can benefit from it.
This library follows "Using Extensions to replace Modifications" principle
- Keywords __WEAK and __OVERRIDE_WEAK are introduced for default functions and extensions; it is similar to the concept of "virtual functions" and "override functions" in C#.
  - arm_2d_async.c is used to override some infrastructure functions in arm_2d.c to support asynchronous mode in the programmers' mode.
  - arm_2d_helium.c is used to override some default software algorithm implementations across the library.
- For the way of adding supports for hardware accelerations. Please click to here for details.