From 28d76d8b3f27a54da791b6eb4a208ce9ce06459b Mon Sep 17 00:00:00 2001 From: Paul Albertella Date: Wed, 25 May 2022 16:07:56 +0100 Subject: [PATCH] Add draft methodology * From Safety Architecture WG minutes WW21 Signed-off-by: Paul Albertella --- methodology/architecture.md | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100644 methodology/architecture.md diff --git a/methodology/architecture.md b/methodology/architecture.md new file mode 100644 index 0000000..477f491 --- /dev/null +++ b/methodology/architecture.md @@ -0,0 +1,17 @@ +# Kernel Safety Architecture Methodology + +## Goals + +* Provide an architectural break down and description of the Kernel in supporting an allocated top level requirement +* Enable and execute an STPA safety analysis to verify Linux to be capable and fit to meet an allocated top level safety requirement + +## Flow of Analysis + +* Safety Requirement Definition: an initial safety requirement must be allocated to the Kernel as a whole from the safety concept of domain specific WGs. +* Scope Identification: given a safety requirement, the code functionally supporting such requirement must be comprehensively identified +* Initial partitioning into functional blocks: one or more functional blocks in the scope of the code above must be identified and for each of these blocks we should describe: +* Interfaces with the other blocks (NOTE: only interfaces that are meaningful in functionally supporting the allocated requirement) +* Functionalities allocated to each functional block (NOTE: only functionalities that are meaningful for fulfilling the allocated requirement) +* For each of the identified functionalities the role of the interfaces shall be described (under which conditions they are invoked) +* Safety Analysis: Do an STPA analysis and define derived safety requirements for each of the functional blocks as in 3) +* Iterate: Evaluate functional blocks complexity vs allocated safety requirements and eventually iterate back in 1) or stop here if not needed (complexity is acceptable)