Uf2File, Reader, Writer

[mestrode]

here is my Uf2File, Reader and Writer implementation

Unfortunately the writer feature does require std due to:

• File I/O operations - std::fs::write(), std::fs::read() for file-based convenience methods
• I/O traits - std::io::Write, std::io::Read for stream-based operations
• String manipulation - ToString trait for converting numbers to strings (used in extensions)
• MD5 hashing - The md5 crate dependency requires std for checksum calculations
• Path handling - std::path::Path for file path operations
• Error handling - std::error::Error trait implementations

That’s probably too much for a workaround. However, Block, Uf2File and Reader do not depend on std.

I have added some synthetic UF2 test files. The reader test, however, only reads the file – it does not check all data fields.

The UF2 specification could be clearer. Some details are also ambiguous. This implementation therefore does not cover the entire specific

[liamkinne]

Please see review comments. Once those are addressed I will probably do a pass over everything to make sure all of the APIs are something I'm happy to commit to before cutting a new release.

[mestrode]

last commit does cover invalid Block Numbers (>= TotalBlockNumbers)

Beyond that, there are additional requirements in the spec, I like to skip:

• File Container Support
• NotMainFlash Flag is supported, but must be set manually
• Extensions defined but has no API
  • SHA-2 Checksum
  • Device Type Identifier
  • Description Extension Tag