RDKDEV-1444, RDKBDEV-3389 Add Documentation RBus

[gourivarma3]

RDKDEV-1444, RDKBDEV-3389
Reason for Change:
To add a generic component Documentation for rbus.
Fix:
Added the README.md documentation

Signed-off-by: gourivarma3

[Copilot]

Pull request overview

Adds a new, comprehensive docs/README.md intended to provide generic RBus component documentation (architecture, threading, modules, configuration, and example flows) to complement existing repository docs.

Changes:

• Introduces an end-to-end RBus documentation page covering design, call flows, internal modules, and configuration.
• Documents build-time CMake options and key runtime/service dependencies.
• Adds illustrative Mermaid diagrams and CLI usage examples.

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[Copilot]

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Copilot reviewed 1 out of 1 changed files in this pull request and generated 4 comments.

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Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (2)

docs/README.md:110

• The description for WITH_SPAKE2 still calls SPAKE2+ a “cipher”, but in this repo SPAKE2+ is used for key exchange and payload encryption is performed with AES (see src/rtmessage/rtCipher.c). Please reword to avoid implying SPAKE2+ itself is the encryption algorithm.

| `WITH_SPAKE2=ON`              | `WITH_SPAKE2=1`        | Enables SPAKE2+ key-exchange cipher between `rtrouted` and clients                                    | OFF                                  |

docs/README.md:252

• This module description implies SPAKE2+ directly “encrypts message payloads”. In the implementation SPAKE2+ is used for key exchange and AES is used for the actual message encryption (src/rtmessage/rtCipher.c). Reword to describe both roles explicitly.

| **Cipher (SPAKE2+)**      | Optional message encryption layer built on the SPAKE2+ password-authenticated key-exchange protocol. Encrypts message payloads between `rtrouted` and clients when enabled at compile time.                                                                                                                                                 | `rtCipher.c`, `rtCipher.h`                                                                             |

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (1)

docs/README.md:110

• The build-options table describes WITH_SPAKE2 as enabling a “key-exchange cipher”. In this repo SPAKE2+ is used for key exchange only; payload encryption uses AES after deriving the shared key (see src/rtmessage/rtCipher.c). This wording is technically inaccurate and contradicts the earlier bullet that correctly distinguishes SPAKE2+ from AES.

| `WITH_SPAKE2=ON`              | `WITH_SPAKE2=1`        | Enables SPAKE2+ key-exchange cipher between `rtrouted` and clients                                    | OFF                                  |

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (2)

docs/README.md:110

• The build-option description calls SPAKE2+ a “key-exchange cipher”, which is technically incorrect in this repo: SPAKE2+ is used for key exchange, and payload encryption uses AES (see src/rtmessage/rtCipher.c). Please reword this table row to avoid implying SPAKE2+ is the encryption cipher.

| `WITH_SPAKE2=ON`              | `WITH_SPAKE2=1`        | Enables SPAKE2+ key-exchange cipher between `rtrouted` and clients                                    | OFF                                  |

docs/README.md:252

• This module description still implies SPAKE2+ itself “encrypts message payloads”. In the implementation, SPAKE2+ derives the shared key and AES encrypts/decrypts the payload. Consider updating the row title/description to reflect both roles for accuracy and to match the earlier Key Features section.

| **Cipher (SPAKE2+)**      | Optional message encryption layer built on the SPAKE2+ password-authenticated key-exchange protocol. Encrypts message payloads between `rtrouted` and clients when enabled at compile time.                                                                                                                                                 | `rtCipher.c`, `rtCipher.h`                                                                             |

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

Suppressed comments (2)

docs/README.md:110

• The WITH_SPAKE2 option description calls SPAKE2+ a “key-exchange cipher”, but in this repo SPAKE2+ is used for key exchange and payload encryption is done with AES (see src/rtmessage/rtCipher.c calling aes_encrypt/aes_decrypt). Reword to avoid implying SPAKE2+ is the cipher.

| `WITH_SPAKE2=ON`              | `WITH_SPAKE2=1`        | Enables SPAKE2+ key-exchange cipher between `rtrouted` and clients                                    | OFF                                  |

docs/README.md:225

• This module description still frames SPAKE2+ as the encryption layer. In the implementation SPAKE2+ derives the shared key (Ke), and AES performs the actual encrypt/decrypt operations (rtCipher_EncryptWithKey/rtCipher_DecryptWithKey). Consider reflecting both roles for accuracy.

| **Cipher (SPAKE2+)**      | Optional message encryption layer built on the SPAKE2+ password-authenticated key-exchange protocol. Encrypts message payloads between `rtrouted` and clients when enabled at compile time.                                                                                                                                                 | `rtCipher.c`, `rtCipher.h`                                                                             |