Support subdivided nRF52 MOTA bridges

tools/lora_ota/build_rak3401_accelerated_bridges.py

@@ -44,6 +44,10 @@ class Target:
     source_commit: str
     bridge_stage: int = 0
     os_stage: int = 0
+    os_stage_part: int = 0
+    os_stage_parts: int = 0
+    os_stage_subpart: int = 0
+    os_stage_subparts: int = 0
     split_stage5: str = ""
     mymesh_opt: str = ""
     flood_rule_engine: bool = True
@@ -255,7 +259,9 @@ def main() -> int:
             firmware_version = f"v{target.version}-{VERSION_SUFFIX}"
             build_env = dict(os.environ)
             for name in (
-                "MOTA_BRIDGE_OS_STAGE", "MOTA_BRIDGE_SPLIT_STAGE5",
+                "MOTA_BRIDGE_OS_STAGE", "MOTA_BRIDGE_OS_STAGE_PART",
+                "MOTA_BRIDGE_OS_STAGE_PARTS", "MOTA_BRIDGE_OS_STAGE_SUBPART",
+                "MOTA_BRIDGE_OS_STAGE_SUBPARTS", "MOTA_BRIDGE_SPLIT_STAGE5",
                 "MOTA_BRIDGE_MY_MESH_OPT", "MOTA_BRIDGE_OS_VERBOSE",
                 "PLATFORMIO_BUILD_FLAGS", "PLATFORMIO_EXTRA_SCRIPTS",
             ):
@@ -272,6 +278,12 @@ def main() -> int:
             if target.os_stage:
                 build_env["MOTA_BRIDGE_OS_STAGE"] = str(target.os_stage)
                 build_env["PLATFORMIO_EXTRA_SCRIPTS"] = f"pre:{SELECTIVE_OS_HOOK}"
+            if target.os_stage_parts:
+                build_env["MOTA_BRIDGE_OS_STAGE_PART"] = str(target.os_stage_part)
+                build_env["MOTA_BRIDGE_OS_STAGE_PARTS"] = str(target.os_stage_parts)
+            if target.os_stage_subparts:
+                build_env["MOTA_BRIDGE_OS_STAGE_SUBPART"] = str(target.os_stage_subpart)
+                build_env["MOTA_BRIDGE_OS_STAGE_SUBPARTS"] = str(target.os_stage_subparts)
             if target.split_stage5:
                 build_env["MOTA_BRIDGE_SPLIT_STAGE5"] = target.split_stage5
             if target.mymesh_opt:
@@ -315,6 +327,10 @@ def main() -> int:
             record["build_flags"] = flags
             record["bridge_stage"] = target.bridge_stage
             record["os_stage"] = target.os_stage
+            record["os_stage_part"] = target.os_stage_part
+            record["os_stage_parts"] = target.os_stage_parts
+            record["os_stage_subpart"] = target.os_stage_subpart
+            record["os_stage_subparts"] = target.os_stage_subparts
             record["split_stage5"] = target.split_stage5
             record["mymesh_opt"] = target.mymesh_opt
             record["flood_rule_engine"] = target.flood_rule_engine

tools/lora_ota/rak3401_selective_os.py

@@ -3,8 +3,8 @@
 Stage 1 size-optimizes crypto/Curve25519 units first. The remaining C/C++
 units are assigned deterministically to stages 2 through 13. A stage includes
 all earlier stages, so every intermediate is a normal bootable build and stage
-13 is equivalent to globally selecting ``-Os``. The last two primary buckets
-are subdivided because their measured nRF52 deltas exceeded internal staging.
+13 is equivalent to globally selecting ``-Os``. A selected stage can also be
+enabled cumulatively in deterministic parts when a board needs smaller deltas.
 """
 
 import hashlib
@@ -22,6 +22,21 @@ except ValueError as exc:
 if STAGE < 1 or STAGE > 13:
     raise RuntimeError("MOTA_BRIDGE_OS_STAGE must be in 1..13")
 
+try:
+    STAGE_PART = int(os.environ.get("MOTA_BRIDGE_OS_STAGE_PART", "1"))
+    STAGE_PARTS = int(os.environ.get("MOTA_BRIDGE_OS_STAGE_PARTS", "1"))
+    STAGE_SUBPART = int(os.environ.get("MOTA_BRIDGE_OS_STAGE_SUBPART", "1"))
+    STAGE_SUBPARTS = int(os.environ.get("MOTA_BRIDGE_OS_STAGE_SUBPARTS", "1"))
+except ValueError as exc:
+    raise RuntimeError("MOTA bridge stage part values must be integers") from exc
+
+if STAGE_PARTS < 1 or STAGE_PART < 1 or STAGE_PART > STAGE_PARTS:
+    raise RuntimeError("MOTA bridge stage part must be in 1..stage parts")
+if STAGE_SUBPARTS < 1 or STAGE_SUBPART < 1 or STAGE_SUBPART > STAGE_SUBPARTS:
+    raise RuntimeError("MOTA bridge stage subpart must be in 1..stage subparts")
+if STAGE_PARTS == 1 and STAGE_SUBPARTS != 1:
+    raise RuntimeError("MOTA bridge stage subparts require multiple stage parts")
+
 CRYPTO_MARKERS = (
     "ed25519",
     "curve25519",
@@ -152,6 +167,18 @@ def _size_optimize_selected(env, node):
     unit_stage = _unit_stage(path, env)
     if unit_stage > STAGE:
         return node
+    if unit_stage == STAGE and STAGE_PARTS > 1:
+        normalized = _normalized_unit_path(path, env)
+        digest = hashlib.sha256(normalized.encode("utf-8")).digest()
+        bucket = digest[4] % STAGE_PARTS
+        if bucket >= STAGE_PART:
+            return node
+        if (
+            bucket == STAGE_PART - 1
+            and STAGE_SUBPARTS > 1
+            and digest[5] % STAGE_SUBPARTS >= STAGE_SUBPART
+        ):
+            return node
     if (
         STAGE == 5
         and unit_stage == 5
@@ -175,6 +202,13 @@ def _size_optimize_selected(env, node):
 
 
 print(f"MOTA bridge selective optimizer stage {STAGE}/13")
+if STAGE_PARTS > 1:
+    print(f"MOTA bridge stage {STAGE} cumulative part {STAGE_PART}/{STAGE_PARTS}")
+if STAGE_SUBPARTS > 1:
+    print(
+        f"MOTA bridge stage {STAGE} current bucket subpart "
+        f"{STAGE_SUBPART}/{STAGE_SUBPARTS}"
+    )
 if STAGE == 5 and os.environ.get("MOTA_BRIDGE_SPLIT_STAGE5") == "first":
     print("MOTA bridge stage 5 split: first half")
 env.AddBuildMiddleware(_size_optimize_selected)