feat: Add no-heap static allocation PAL backend for lockstep mode

CMakeLists.txt

@@ -67,6 +67,7 @@ option(ENABLE_WERROR "Treat compiler warnings as errors (recommended for CI)" OF
 option(SOMEIP_USE_FREERTOS "Use FreeRTOS for threading primitives" OFF)
 option(SOMEIP_USE_THREADX  "Use ThreadX for threading primitives" OFF)
 option(SOMEIP_USE_LWIP     "Use lwIP for network sockets" OFF)
+option(SOMEIP_USE_STATIC_ALLOC "Use static allocation (no heap)" OFF)
 
 # RTOS linux/POSIX port runtime tests (Linux only)
 option(SOMEIP_FREERTOS_LINUX_TESTS "Build and run FreeRTOS runtime tests using FreeRTOS POSIX port" OFF)
@@ -196,6 +197,19 @@ if(SOMEIP_USE_LWIP)
     )
 endif()
 
+# --- ETL (Embedded Template Library) for static-allocation containers ---
+if(SOMEIP_USE_STATIC_ALLOC)
+    set(BUILD_TESTS_SAVED ${BUILD_TESTS})
+    set(BUILD_TESTS OFF)
+    FetchContent_Declare(etl
+        GIT_REPOSITORY https://github.com/ETLCPP/etl.git
+        GIT_TAG        20.47.1
+        GIT_SHALLOW    TRUE
+    )
+    FetchContent_MakeAvailable(etl)
+    set(BUILD_TESTS ${BUILD_TESTS_SAVED})
+endif()
+
 # Set policy for FetchContent timestamp handling (CMake 3.24+)
 if(POLICY CMP0135)
     cmake_policy(SET CMP0135 NEW)
@@ -251,6 +265,15 @@ set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
 # Include directories
 include_directories(include)
 
+# Allocation backend (selects containers_impl.h, buffer_pool_impl.h, memory_impl.h)
+# SOMEIP_STATIC_ALLOC is set via target_compile_definitions on opensomeip (PUBLIC),
+# so it propagates to dependents but NOT to PAL mock tests that compile sources directly.
+if(SOMEIP_USE_STATIC_ALLOC)
+    include_directories(include/platform/static)
+else()
+    include_directories(include/platform/dynamic)
+endif()
+
 # Platform backend include directories (selects which *_impl.h files are found)
 if(SOMEIP_USE_FREERTOS)
     include_directories(include/platform/freertos)
@@ -611,6 +634,11 @@ elseif(WIN32)
 else()
     message(STATUS "    Networking ............ BSD sockets")
 endif()
+if(SOMEIP_USE_STATIC_ALLOC)
+    message(STATUS "    Allocation ............ Static (ETL, no heap)")
+else()
+    message(STATUS "    Allocation ............ Dynamic (STL)")
+endif()
 message(STATUS "  Build tests ............. ${BUILD_TESTS}")
 message(STATUS "  Build examples .......... ${BUILD_EXAMPLES}")
 message(STATUS "  Dev tools ............... ${SOMEIP_DEV_TOOLS}")

docs/requirements/implementation/architecture.rst

@@ -190,6 +190,27 @@ Testing Infrastructure
 
    **Code Location**: ``tests/``
 
+Static Allocation
+-----------------
+
+.. requirement:: Static Allocation Policy
+   :id: REQ_ARCH_008
+   :satisfies: REQ_ARCH_003
+   :status: implemented
+   :priority: high
+   :category: happy_path
+   :verification: Build with ``SOMEIP_USE_STATIC_ALLOC=ON`` and run unit tests with heap-interception enabled (``REQ_PAL_NOOP_HEAP_VERIFY``). Verify no ``malloc``/``new`` calls occur during protocol operation. Inspect container and pool types for compile-time capacity bounds.
+
+   When ``SOMEIP_USE_STATIC_ALLOC`` is enabled, the stack shall not perform
+   dynamic memory allocation (heap) at runtime. All buffers, containers, and
+   object pools shall use compile-time-sized static storage.
+
+   **Rationale**: Freedom from interference per ISO 26262 Part 6 clause 7.4.6;
+   WCET determinism per clause 7.4.11.
+
+   **Code Location**: ``CMakeLists.txt``, ``include/platform/static/``,
+   ``src/platform/static/``
+
 Traceability
 ============