Update notes from 3.4.3 to 4.0.0a1

[zimri-leisher]

Here is a list of all the breaking changes that I couldn't find documented in the release notes:

• POINTER_CAST removed, couldnt find what to replace it with
• New Os::File::OverwriteType argument to file open
• ByteStreamRecv/Send replaced with ByteStreamData or BufferSend
• No more Send/RecvStatus, just ByteStreamStatus
• Svc::TimerVal has been changed to Os::RawTime?

In the release notes, I would really appreciate it if there were a complete list of classes or types that had breaking changes in an update. That way I could easily Ctrl+F

[zimri-leisher]

• What is comstub for? Is it just a layer that retries if it gets SEND_RETRY?
• Unsure if DP is good for our use case... want to try it but don't want to get locked into a way of thinking and have it be not fully supported

[LeStarch]

The framer/deframer pipeline are designed to talk to a "radio" and follow the comm stub interface: https://github.com/nasa/fprime/blob/devel/docs/reference/communication-adapter-interface.md.

Since drivers do not, and should not implement this interface, the ComStub provides radio like capability when using a bare driver.

[LeStarch]

@timcanham can you speak to the data product note here?

[zimri-leisher]

The framer/deframer pipeline are designed to talk to a "radio" and follow the comm stub interface: https://github.com/nasa/fprime/blob/devel/docs/reference/communication-adapter-interface.md.

Since drivers do not, and should not implement this interface, the ComStub provides radio like capability when using a bare driver.

Excellent, I see now. Thank you!