Product: RBC_SA, the Specific Application of the reference RBC (repository RBC_SA). Layer: Specific Application, above RBC_GA and RBC_GP. Language: C99 plus shell. Assessment unit: Specific Application (assessed per project), see ../../docs/safety/CERTIFICATION_PLAN.dox.

Responsibility

Everything that is specific to one deployment, in two parts kept in one product:

Site data. Two static libraries implement the site contracts that RBC_GP and RBC_GA define: sa::site::gp (full RailML topology, ab_siteGP.h) and sa::site::ga (route-only projection, ab_siteGA.h). The tables are generated from etc/site/ab_site.railml.xml.
Packaging. Self-extracting installers for the RBC binaries and their shared libraries, chosen per role (A, B, gateway) by etc/config/packaging.conf, plus the Docker image build that proves an installer works.

"SA" reads both as "standalone installer" and "Specific Application"; the name is a deliberate coincidence.

It does not contain railway logic (RBC_GA), the ERTMS engine (RBC_GP), or platform code, and it does not build source itself: run test/RBC_Test_Env/etc/scripts/build_toolchains.sh (and build_channels.sh for compiler diversity) first.

Interfaces exposed to other products

Interface	Form	Consumed by	Notes
sa::site::gp	Static library implementing ab_siteGP.h	RBC_GP	Full topology
sa::site::ga	Static library implementing ab_siteGA.h	RBC_GA	Symbols are GA-namespaced on purpose
Site data source	etc/site/ab_site.railml.xml	Generators, RBC_Test_Env, simulators	Single source of truth for topology
Packaging configuration	etc/config/packaging.conf	Deployment engineers	Per-role target and compiler channel
Installer	dist/install/rte-rbc2oo2-<target>-installer.sh	Deployment	Precheck, extract, postcheck, next steps
show_product_structure.sh	Read-only report (-j for JSON)	Release and evidence tooling	Role, target, binary, size, CRC64, SHA-256
RBC image	Dockerfile (context: workspace root)	RBC_Test_Env compose stack	Runs the installer during the build

Interfaces required

Needs	From	How
ab_siteGP.h, ab_siteGA.h	RBC_GP, RBC_GA	Header-only reach (RTE_RBC2OO2GP_DIR, RTE_RBC2OO2GA_DIR)
Built binaries and libraries	RBC_GP dist/<platform>[/<channel>]/	Packaging only

Build and use

cmake -S . -B build && cmake --build build && cmake --install build --prefix .   # site libraries
./build_installers.sh            # config-driven; -c <conf> for another config, -a to sweep every built target
etc/scripts/show_product_structure.sh

Details, installer behavior, Docker notes and limits: CLAUDE.md.