fix(native-usb): isolate two-pair transport and hand off read status in IRQ

tests/test_switch2_usb_probe_storage_native.py

@@ -0,0 +1,75 @@
+from __future__ import annotations
+
+import shutil
+import subprocess
+from pathlib import Path
+
+import pytest
+
+
+@pytest.mark.parametrize(
+    ("left", "composite", "hub", "count", "overlap"),
+    [
+        (False, False, False, 1, False),
+        (True, False, False, 1, False),
+        (False, True, False, 2, False),
+        (False, False, True, 2, False),
+        (False, False, True, 4, False),
+        (False, False, True, 4, True),
+    ],
+    ids=[
+        "right",
+        "left",
+        "composite",
+        "hub-one-pair",
+        "hub-two-pairs",
+        "overlap-pair-b",
+    ],
+)
+def test_switch2_usb_probe_storage_native(
+    tmp_path: Path, left: bool, composite: bool, hub: bool, count: int, overlap: bool
+) -> None:
+    root = Path(__file__).resolve().parents[1]
+    compiler = shutil.which("c++") or shutil.which("g++")
+    assert compiler is not None, "a host C++ compiler is required"
+    probe = root / "tools" / "switch2_usb_probe"
+    # Stub geometry: 2 MiB flash, 8 KiB BTstack, 8 KiB configuration, 256 KiB
+    # profiles. Link the SDK's end-of-image symbol at the exact reserved boundary,
+    # or one byte into pair B while still safely below both original pair A banks.
+    reserved_start = 0x1BC000 - max(2, count) * 8192
+    binary_end = reserved_start + int(overlap)
+    executable = tmp_path / "switch2_usb_probe_storage_test"
+    subprocess.run(
+        [
+            compiler,
+            "-std=c++17",
+            "-Wall",
+            "-Wextra",
+            "-Werror",
+            "-pedantic",
+            f"-DSWITCH2_PROBE_JOYCON_LEFT={int(left)}",
+            f"-DSWITCH2_PROBE_COMPOSITE={int(composite)}",
+            f"-DSWITCH2_PROBE_HUB={int(hub)}",
+            f"-DSWITCH2_PROBE_NEUTRAL_INPUT={int(hub)}",
+            f"-DPROBE_CONTROLLER_COUNT={count}",
+            f"-DPROBE_TEST_STORAGE_OVERLAP={int(overlap)}",
+            f"-I{root / 'tests' / 'switch2_usb_probe_storage_native_stubs'}",
+            f"-I{root / 'src' / 'firmware'}",
+            f"-I{probe}",
+            str(root / "tests" / "switch2_usb_probe_storage_test.cpp"),
+            str(probe / "storage.cpp"),
+            str(
+                root
+                / "src"
+                / "firmware"
+                / "configuration"
+                / "configuration_storage.cpp"
+            ),
+            f"-Wl,--defsym=__flash_binary_end=probe_test_flash+{binary_end}",
+            "-o",
+            str(executable),
+        ],
+        check=True,
+        cwd=root,
+    )
+    subprocess.run([str(executable)], check=True, cwd=root)