Merge pull request #6191 from emmanuelsearch/memos

Doc: initial RIOT developer memo + directory structure

doc/memos/README.md

+# RIOT Developer Memos
+
+The index below lists the RDMs that were published so far.
+
+- [RDM0 : RIOT Developer Memo Format, Publishing and Maintenance Process](./rdm0000.md)
\ No newline at end of file

doc/memos/rdm0000.md

+
+- RDM: 0
+- Title: RIOT Developer Memo Format, Publishing and Maintenance Process
+- Author: Emmanuel Baccelli
+- Status: Active
+- Type: Process
+- Created: October 2018
+
+## Abstract
+
+This memo describes a template for memos produced by the RIOT maintainers
+community, targeting primarily RIOT developers.
+
+## Status
+
+This document is a product of the community of RIOT maintainers, and aims to
+represent the consensus within this community. The content of this document is
+licensed with a Creative Commons CC-BY-SA license.
+
+## Terminology
+
+This memo uses the [RFC2119](https://www.ietf.org/rfc/rfc2119.txt) terminology
+and the following acronyms:
+
+- RDM: RIOT Developer Memo
+- PR: git Pull-Request to RIOT's master branch on GitHub
+- ACK: acknowledgement from a RIOT maintainer, concerning a pull-request to the
+master branch of RIOT on GitHub
+
+# 1. Introduction
+
+In order to facilitate RIOT maintenance in the long term and at large scale,
+additional documentation complementing code and usual code documentation is
+needed. For instance, such memos are expected to describe and give explanations
+about architectural design decisions, code structure etc. Other memos might
+also describe other aspects of RIOT activity, including, but not limited to,
+RIOT community processes, position with respect to some related external
+technical debates, pitfalls and best practices...
+
+This memo specifies a format for such memos and the process of discussing their
+content before publication. Format and processes are somewhat inspired by
+[IETF](http://ietf.org/) processes and documents such as Request For Comments
+(RFC) and Python Enhancement Proposals [PEPs](https://www.python.org/dev/peps/).
+
+# 2. RIOT Developers Memo Format
+
+RIOT Developer Memos (RDM) are written in English, using the Markdown (.md)
+format, with less than 80 characters per line. Each memo has a unique
+identification number indicated in its header,
+e.g. this memo is RDM0.
+
+The structure of a memo MUST contain:
+
+1. a preamble as defined below,
+2. the content of the memo structured as needed,
+3. a postamble as defined below.
+
+The preamble of the memo should be structured as such:
+
+1. a header formatted as the header of this memo,
+2. a short abstract,
+3. a status for the memo stating its license and the category of the memo (e.g.
+that it is a consensus document),
+4. optionally, a terminology section which recalls/disambiguates definition of
+terms that are key to the memo.
+
+The core content of the memo is structured as deemed necessary. However, during
+the review process, care must be taken to follow the below principles as much
+as possible:
+
+1. one memo = one problem/aspect,
+2. start by crisply explaining and motivating the one problem/aspect the memo
+targets,
+3. memos are expected to be of normative and durable nature, hence: keep a memo
+as concise as possible without impairing clarity, and factor out content that
+id likely to quickly become out-of-date.
+
+The postamble of the memo should be structured as such:
+
+1. (optional) acknowledgements section thanking contributors other than the
+authors,
+2. a section with the main references that relate to the content, with a strong
+preference for permanent, self-contained references,
+3. the list of revisions so far and corresponding changelog,
+4. contact information to reach the author(s).
+
+# 3. Memo Publishing and Maintenance Process
+
+Each new memo MUST be proposed as a pull-request (PR),
+and discussed the same way RIOT code PRs are processed on GitHub.
+
+Initially, a proposed RDM is identified by its temporary file name
+of shape rdm-draft-<author>-<topic>.md (for
+example: rdm-draft-baccelli-rdm-format.md) instead of a number
+assigned at a later stage.
+At this stage, the RDM's header indactes status "draft".
+
+Proposing an RDM is non-compulsory. There is no restriction on when, in the
+development cycle, an RDM can be PRed. However, RDMs on design decisions and
+architecture are typically expected to describe something rather stable (that is
+already merged in the main branch of RIOT, or about to be merged).
+
+Once proposed, a memo MUST have received an ACK by at least 3 maintainers other
+than the author(s) of the memo, before its publication.
+
+At this stage, the RDM is assigned a permanent RDM number (the next available),
+its status is changed to "active" and it is merged in the master branch of RIOT.
+Once merged into the master branch of RIOT, a memo is considered published.
+
+Small changes/clarifications may be subsequently PRed to improve a memo, using
+the same RDM number. In this case, a (monotonically increasing) revision number
+is issued and a changelog is added -- see Revision section in postamble below.
+
+Bigger changes should result in a new memo with another
+RDM number, deprecating the old memo. In this case, the deprecated memo must
+be modified such that its status indicates "deprecated by [RDM XXXX](./rdmXXXX.md)"
+where X is the RDM number of the new memo.
+
+A dedicated directory in RIOT codebase (RIOT/doc/memos) contains all the memos.
+It is acceptable to add complementary content such as graphical elments
+(in RIOT/doc/memos/files/) to illustrate the memo, as done with the RIOT logo
+below (see Figure 1, given here for pure sake of example).
+However graphical content should be kept to the bare
+minimum, as it is easy to get lost in "shiny slideware".
+
+
+![Figure 1. RIOT logo.](./files/rdm0000/RIOT-logo.png "RIOT logo")
+<p align="justify">
+Figure 1. The RIOT logo.
+</p>
+
+
+## Acknowledgements
+
+Thanks to Thomas Eichinger, Oliver Hahm, Ludwig Knüpfer, Martine Lenders,
+Sebastian Meiling, Hauke Petersen, Dan Petry, Kaspar Schleiser and
+Matthias Wählisch for their comments and suggestions.
+
+## References
+
+- Internet Engineering Task Force ([IETF](http://ietf.org/))
+- Guide to [Contributing to RIOT](https://github.com/RIOT-OS/RIOT/wiki/Contributing-to-RIOT)
+
+## Revision
+
+- Rev2: added title in metadata and specification of temporary RDM naming
+- Rev1: added text on non-compulsory nature of RDMs
+- Rev0: initial document
+
+## Contact
+
+The author of this memo can be contacted via email at emmanuel.baccelli@inria.fr