Merge remote-tracking branch 'origin/dev' into esp8266-native-build-surgery

KEY_LDSCRIPT replaces the bare literal at both the table entry and the
lookup, so a typo cannot silently fall back to the layout-moving
default; the regeneration recipe notes that overrides must survive a
refresh; a board pinning an override on an Arduino core <= 2.4.2 warns
that the layout cannot be honored; and board_ld_script gains the test
pinning d1_wroom_02's shipped layout and the size defaults.

esphome/components/esp8266/__init__.py

@@ -35,7 +35,7 @@ from esphome.platformio.toolchain import copy_ccache_script
 from esphome.storage_json import StorageJSON
 from esphome.types import ConfigType
 
-from .boards import BOARDS, ESP8266_LD_SCRIPTS
+from .boards import BOARDS, ESP8266_LD_SCRIPTS, board_ld_script
 from .const import (
     CONF_EARLY_PIN_INIT,
     CONF_ENABLE_SERIAL,
@@ -44,6 +44,7 @@ from .const import (
     KEY_BOARD,
     KEY_ESP8266,
     KEY_FLASH_SIZE,
+    KEY_LDSCRIPT,
     KEY_PIN_INITIAL_STATES,
     KEY_SERIAL1_REQUIRED,
     KEY_SERIAL_REQUIRED,
@@ -276,6 +277,31 @@ def check_rosetta() -> None:
         )
 
 
+def _choose_ld_script(board: str, ver: cv.Version) -> str | None:
+    """The flash ld to pin for this board and core, or None for cores
+    without ld-script support."""
+    board_data = BOARDS[board]
+    ld_scripts = ESP8266_LD_SCRIPTS[board_data[KEY_FLASH_SIZE]]
+    if ver <= cv.Version(2, 3, 0):
+        # No ld script support
+        return None
+    if ver <= cv.Version(2, 4, 2):
+        # Old ld script path; the modern per-board override names do not
+        # exist in this core's SDK, so the override cannot be honored.
+        # Substituting the size default would move _FS_end and the
+        # preferences sector, wiping flash-backed state on flash.
+        if KEY_LDSCRIPT in board_data:
+            raise EsphomeError(
+                f"Board {board} requires its {board_data[KEY_LDSCRIPT]} "
+                f"flash layout, which Arduino core {ver} cannot honor; "
+                "use a core newer than 2.4.2"
+            )
+        return ld_scripts[0]
+    # A per-board override preserves a layout the board shipped with
+    # (see d1_wroom_02 in boards.py)
+    return board_ld_script(board_data)
+
+
 @coroutine_with_priority(CoroPriority.PLATFORM)
 async def to_code(config: ConfigType) -> None:
     cg.add(esp8266_ns.setup_preferences())
@@ -397,17 +423,7 @@ async def to_code(config: ConfigType) -> None:
     )
 
     if config[CONF_BOARD] in BOARDS:
-        flash_size = BOARDS[config[CONF_BOARD]][KEY_FLASH_SIZE]
-        ld_scripts = ESP8266_LD_SCRIPTS[flash_size]
-
-        if ver <= cv.Version(2, 3, 0):
-            # No ld script support
-            ld_script = None
-        elif ver <= cv.Version(2, 4, 2):
-            # Old ld script path
-            ld_script = ld_scripts[0]
-        else:
-            ld_script = ld_scripts[1]
+        ld_script = _choose_ld_script(config[CONF_BOARD], ver)
 
         if ld_script is not None:
             cg.add_platformio_option("board_build.ldscript", ld_script)

esphome/components/esp8266/boards.py

@@ -1,3 +1,5 @@
+from .const import KEY_FLASH_SIZE, KEY_LDSCRIPT
+
 FLASH_SIZE_1_MB = 2**20
 FLASH_SIZE_512_KB = FLASH_SIZE_1_MB // 2
 FLASH_SIZE_2_MB = 2 * FLASH_SIZE_1_MB
@@ -164,7 +166,8 @@ ESP8266_BOARD_PINS = {
 }
 
 """
-BOARDS generate with:
+BOARDS generate with (preserve per-board KEY_LDSCRIPT overrides such as
+d1_wroom_02; the recipe emits only name/flash_size):
 
 git clone https://github.com/platformio/platform-espressif8266
 for x in platform-espressif8266/boards/*.json; do
@@ -182,6 +185,19 @@ for x in platform-espressif8266/boards/*.json; do
 done | sort
 """
 
+
+def board_ld_script(board_data: dict) -> str:
+    """The modern (core > 2.4.2) flash linker script for a board: its
+    shipped-layout override, else the size default (the no-FS layout).
+
+    Single source of truth for the PlatformIO pinning in __init__ and the
+    native generator's fallback, so the per-board rule cannot drift.
+    """
+    return board_data.get(
+        KEY_LDSCRIPT, ESP8266_LD_SCRIPTS[board_data[KEY_FLASH_SIZE]][1]
+    )
+
+
 BOARDS = {
     "agruminolemon": {
         "name": "Lifely Agrumino Lemon v4",
@@ -199,6 +215,15 @@ BOARDS = {
         "name": "WeMos D1 mini Pro",
         "flash_size": FLASH_SIZE_16_MB,
     },
+    "d1_wroom_02": {
+        "name": "WeMos D1 ESP-WROOM-02",
+        "flash_size": FLASH_SIZE_2_MB,
+        # This board joined BOARDS after shipping with the manifest default
+        # (64 KB filesystem region); the flash-size default (2m.ld) would
+        # move _FS_end and with it the preferences sector, wiping existing
+        # devices' flash-backed state on update.
+        KEY_LDSCRIPT: "eagle.flash.2m64.ld",
+    },
     "d1": {
         "name": "WEMOS D1 R1",
         "flash_size": FLASH_SIZE_4_MB,
@@ -360,3 +385,112 @@ BOARDS = {
         "flash_size": FLASH_SIZE_4_MB,
     },
 }
+
+
+# Per-board variant dir + identity defines from platform-espressif8266 4.x
+# build.extra_flags; the shared -DESP8266/-DARDUINO_ARCH_ESP8266 are added
+# by the generator.
+#
+# Regenerate ESP8266_BOARD_BUILD with (v4.2.1 is the platform version the
+# native toolchain mirrors; regenerate against the tag when bumping it):
+#
+# git clone -b v4.2.1 https://github.com/platformio/platform-espressif8266
+# python3 - <<'EOF'
+# import json, glob, os
+# for f in sorted(glob.glob("platform-espressif8266/boards/*.json")):
+#     b = json.load(open(f))["build"]
+#     extra = b["extra_flags"]
+#     extra = extra.split() if isinstance(extra, str) else extra
+#     defines = [
+#         e[2:] for e in extra if e not in ("-DESP8266", "-DARDUINO_ARCH_ESP8266")
+#     ]
+#     entries = ", ".join(f'"{d}"' for d in defines) + ("," if len(defines) == 1 else "")
+#     board = os.path.splitext(os.path.basename(f))[0]
+#     print(f'    "{board}": {{"variant": "{b["variant"]}", "defines": ({entries})}},')
+# EOF
+ESP8266_BOARD_BUILD = {
+    "agruminolemon": {
+        "variant": "agruminolemonv4",
+        "defines": ("ARDUINO_ESP8266_AGRUMINO_LEMON_V4",),
+    },
+    "d1": {"variant": "d1", "defines": ("ARDUINO_ESP8266_WEMOS_D1R1",)},
+    "d1_mini": {"variant": "d1_mini", "defines": ("ARDUINO_ESP8266_WEMOS_D1MINI",)},
+    "d1_mini_lite": {
+        "variant": "d1_mini",
+        "defines": ("ARDUINO_ESP8266_WEMOS_D1MINILITE",),
+    },
+    "d1_mini_pro": {
+        "variant": "d1_mini",
+        "defines": ("ARDUINO_ESP8266_WEMOS_D1MINIPRO",),
+    },
+    "d1_wroom_02": {
+        "variant": "d1_mini",
+        "defines": ("ARDUINO_ESP8266_WEMOS_D1WROOM02",),
+    },
+    "eduinowifi": {
+        "variant": "eduinowifi",
+        "defines": ("ARDUINO_ESP8266_SCHIRMILABS_EDUINO_WIFI",),
+    },
+    "esp01": {"variant": "generic", "defines": ("ARDUINO_ESP8266_ESP01",)},
+    "esp01_1m": {"variant": "generic", "defines": ("ARDUINO_ESP8266_ESP01",)},
+    "esp07": {"variant": "generic", "defines": ("ARDUINO_ESP8266_ESP07",)},
+    "esp07s": {"variant": "nodemcu", "defines": ("ARDUINO_ESP8266_ESP07",)},
+    "esp12e": {"variant": "nodemcu", "defines": ("ARDUINO_ESP8266_ESP12",)},
+    "esp210": {"variant": "generic", "defines": ("ARDUINO_ESP8266_ESP210",)},
+    "esp8285": {"variant": "esp8285", "defines": ("ARDUINO_ESP8266_ESP01",)},
+    "esp_wroom_02": {
+        "variant": "nodemcu",
+        "defines": ("ARDUINO_ESP8266_ESP_WROOM_02",),
+    },
+    "espduino": {"variant": "ESPDuino", "defines": ("ARDUINO_ESP8266_ESP13",)},
+    "espectro": {"variant": "espectro", "defines": ("ARDUINO_ESP8266_ESPECTRO_CORE",)},
+    "espino": {"variant": "espino", "defines": ("ARDUINO_ESP8266_ESP12",)},
+    "espinotee": {"variant": "espinotee", "defines": ("ARDUINO_ESP8266_ESP13",)},
+    "espmxdevkit": {
+        "variant": "esp8285",
+        "defines": ("ARDUINO_ESP8266_ESP01", "LED_BUILTIN=16"),
+    },
+    "espresso_lite_v1": {
+        "variant": "espresso_lite_v1",
+        "defines": ("ARDUINO_ESP8266_ESPRESSO_LITE_V1",),
+    },
+    "espresso_lite_v2": {
+        "variant": "espresso_lite_v2",
+        "defines": ("ARDUINO_ESP8266_ESPRESSO_LITE_V2",),
+    },
+    "gen4iod": {"variant": "generic", "defines": ("ARDUINO_GEN4_IOD",)},
+    "heltec_wifi_kit_8": {
+        "variant": "wifi_kit_8",
+        "defines": ("ARDUINO_wifi_kit_8",),
+    },
+    "huzzah": {"variant": "adafruit", "defines": ("ARDUINO_ESP8266_ADAFRUIT_HUZZAH",)},
+    "inventone": {"variant": "inventone", "defines": ("ARDUINO_ESP8266_INVENT_ONE",)},
+    "modwifi": {"variant": "generic", "defines": ("ARDUINO_MOD_WIFI_ESP8266",)},
+    "nodemcu": {"variant": "nodemcu", "defines": ("ARDUINO_ESP8266_NODEMCU",)},
+    "nodemcuv2": {"variant": "nodemcu", "defines": ("ARDUINO_ESP8266_NODEMCU_ESP12E",)},
+    "oak": {"variant": "oak", "defines": ("ARDUINO_ESP8266_OAK",)},
+    "phoenix_v1": {
+        "variant": "phoenix_v1",
+        "defines": ("ARDUINO_ESP8266_PHOENIX_V1",),
+    },
+    "phoenix_v2": {
+        "variant": "phoenix_v2",
+        "defines": ("ARDUINO_ESP8266_PHOENIX_V2",),
+    },
+    "sonoff_basic": {"variant": "itead", "defines": ("ARDUINO_ESP8266_SONOFF_BASIC",)},
+    "sonoff_s20": {"variant": "itead", "defines": ("ARDUINO_ESP8266_SONOFF_S20",)},
+    "sonoff_sv": {"variant": "itead", "defines": ("ARDUINO_ESP8266_SONOFF_SV",)},
+    "sonoff_th": {"variant": "itead", "defines": ("ARDUINO_ESP8266_SONOFF_TH",)},
+    "sparkfunBlynk": {"variant": "thing", "defines": ("ARDUINO_ESP8266_THING",)},
+    "thing": {"variant": "thing", "defines": ("ARDUINO_ESP8266_THING",)},
+    "thingdev": {"variant": "thing", "defines": ("ARDUINO_ESP8266_THING_DEV",)},
+    "wifi_slot": {"variant": "wifi_slot", "defines": ("ARDUINO_AMPERKA_WIFI_SLOT",)},
+    "wifiduino": {"variant": "wifiduino", "defines": ("ARDUINO_WIFIDUINO_ESP8266",)},
+    "wifinfo": {"variant": "wifinfo", "defines": ("ARDUINO_WIFINFO",)},
+    "wio_link": {"variant": "wiolink", "defines": ("ARDUINO_ESP8266_WIO_LINK",)},
+    "wio_node": {"variant": "nodemcu", "defines": ("ARDUINO_ESP8266_ESP_WROOM_02",)},
+    "xinabox_cw01": {
+        "variant": "xinabox",
+        "defines": ("ARDUINO_ESP8266_XINABOX_CW01",),
+    },
+}

esphome/components/esp8266/build_surgery.py

@@ -0,0 +1,123 @@
+"""Linker-script surgery shared with the native (PlatformIO-free) toolchain.
+
+These mirror the PlatformIO extra scripts in this directory
+(``relocate_ratetable.py.script`` and ``testing_mode.py.script``), which run
+inside SCons and must stay self-contained. The native build generator applies
+the same patches to the linker scripts it generates, so the logic lives here
+as plain functions. Keep both in sync when changing either.
+``segment_length`` is native-toolchain-only and has no script twin.
+"""
+
+from __future__ import annotations
+
+from collections.abc import Collection
+import hashlib
+import re
+
+# Move the NONOS SDK wifi rate tables from flash to DRAM; see
+# relocate_ratetable.py.script for the full background (NONOS SDK issue 320).
+RATETABLE_RULE = "*libnet80211.a:ieee80211_phy.o(.irom.text .irom.text.*)"
+_RATETABLE_COMMENT = (
+    "/* ESPHome: wifi rate tables must live in DRAM, see NONOS SDK issue 320 */"
+)
+# Match the whole line: "_data_start" is also a substring of the
+# "_dport0_data_start" line in the earlier .dport0.data section
+_RATETABLE_ANCHOR = re.compile(r"^\s*_data_start = ABSOLUTE\(\.\);", re.MULTILINE)
+
+# Memory sizes for testing mode (allow larger builds for CI component grouping)
+TESTING_IRAM_SIZE = "0x200000"  # 2MB
+TESTING_DRAM_SIZE = "0x200000"  # 2MB
+TESTING_FLASH_SIZE = "0x2000000"  # 32MB
+
+
+def relocate_ratetable(content: str) -> str:
+    """Insert the rate-table DRAM rule into a generated common linker script."""
+    if RATETABLE_RULE in content:
+        return content
+    match = _RATETABLE_ANCHOR.search(content)
+    if match is None:
+        raise RuntimeError(
+            "'_data_start' anchor not found in the generated linker script; "
+            "cannot apply wifi rate table DRAM relocation "
+            "(has the Arduino core linker script changed?)"
+        )
+    insert_pos = match.end()
+    return (
+        content[:insert_pos]
+        + f"\n    {_RATETABLE_COMMENT}"
+        + f"\n    {RATETABLE_RULE}"
+        + content[insert_pos:]
+    )
+
+
+_TESTING_SEGMENT_SIZES = {
+    "iram1_0_seg": TESTING_IRAM_SIZE,
+    "dram0_0_seg": TESTING_DRAM_SIZE,
+    "irom0_0_seg": TESTING_FLASH_SIZE,
+}
+
+
+def _segment_line_re(segment_name: str) -> re.Pattern[str]:
+    """The MEMORY line for one segment: ``<seg> : org = 0x..., len = 0x...``.
+
+    Anchored to the start of the line so a name never matches inside a
+    longer one (``ram0_0_seg`` must not read ``dram0_0_seg``). The size
+    group stops at the hex digits, leaving any ``ul`` suffix (from the
+    preprocessed ``MMU_IRAM_SIZE``) in place.
+    """
+    return re.compile(
+        rf"(^[ \t]*{re.escape(segment_name)}"
+        r"\s*:\s*org\s*=\s*0x[0-9a-fA-F]+\s*,\s*len\s*=\s*)"
+        r"(0x[0-9a-fA-F]+)",
+        re.MULTILINE,
+    )
+
+
+def apply_testing_memory_patches(content: str, segments: Collection[str]) -> str:
+    """Enlarge the named memory segments so grouped CI test builds can link.
+
+    Each caller passes the segments its linker script defines: the
+    generated common ld carries ``iram1_0_seg``; the flash ld carries
+    ``dram0_0_seg`` and ``irom0_0_seg``. A segment that fails to match
+    raises, since a silently kept real memory limit would fail grouped
+    builds far from the cause.
+    """
+    for segment in _TESTING_SEGMENT_SIZES:
+        if segment not in segments and _segment_line_re(segment).search(content):
+            raise RuntimeError(
+                f"Testing-mode segment {segment} is present in the linker "
+                "script but was not selected for patching"
+            )
+    for segment in segments:
+        if segment not in _TESTING_SEGMENT_SIZES:
+            raise RuntimeError(f"Unknown testing-mode segment {segment!r}")
+        content, count = _segment_line_re(segment).subn(
+            rf"\g<1>{_TESTING_SEGMENT_SIZES[segment]}", content
+        )
+        if count == 0:
+            raise RuntimeError(
+                f"Testing-mode memory patch failed: segment {segment} "
+                "not found (has the Arduino core linker script changed?)"
+            )
+    return content
+
+
+def segment_length(content: str, segment_name: str) -> int | None:
+    """Read a memory segment's length from linker script content.
+
+    Returns None for an absent segment OR an unparsable line; callers must
+    treat None as "no usable budget" and warn (as the Flash summary does),
+    never as "no limit".
+    """
+    match = _segment_line_re(segment_name).search(content)
+    return int(match.group(2), 16) if match else None
+
+
+def surgery_fingerprint() -> str:
+    """Hash of this module's source; linker-script caches include it so an
+    edit here invalidates them."""
+    import inspect
+    import sys
+
+    source = inspect.getsource(sys.modules[__name__])
+    return hashlib.sha256(source.encode()).hexdigest()

esphome/components/esp8266/const.py

@@ -15,6 +15,11 @@ CONF_ENABLE_SERIAL1 = "enable_serial1"
 KEY_WAVEFORM_REQUIRED = "waveform_required"
 KEY_SERIAL_REQUIRED = "serial_required"
 KEY_SERIAL1_REQUIRED = "serial1_required"
+# Set for the native (non-PlatformIO) toolchain's build generator
+KEY_FLASH_MODE = "flash_mode"
+KEY_SCANF_FLOAT = "scanf_float"
+# Per-board flash-layout override consumed by board_ld_script()
+KEY_LDSCRIPT = "ldscript"
 
 # esp8266 namespace is already defined by arduino, manually prefix esphome
 esp8266_ns = cg.global_ns.namespace("esphome").namespace("esp8266")

tests/unit_tests/components/esp8266/test_boards.py

@@ -0,0 +1,33 @@
+"""Tests for the per-board linker-script rule."""
+
+import pytest
+
+from esphome.components.esp8266 import _choose_ld_script
+from esphome.components.esp8266.boards import BOARDS, board_ld_script
+import esphome.config_validation as cv
+from esphome.core import EsphomeError
+
+
+def test_d1_wroom_02_keeps_its_shipped_layout() -> None:
+    """The override must survive a BOARDS regeneration or key typo: the
+    2m.ld default moves _FS_end and the preferences sector on deployed
+    devices."""
+    assert board_ld_script(BOARDS["d1_wroom_02"]) == "eagle.flash.2m64.ld"
+
+
+def test_default_boards_use_the_flash_size_layout() -> None:
+    assert board_ld_script(BOARDS["d1_mini"]) == "eagle.flash.4m.ld"
+    assert board_ld_script(BOARDS["esp01_1m"]) == "eagle.flash.1m.ld"
+
+
+def test_choose_ld_script_paths() -> None:
+    """Old cores get the size default, overriding boards hard-error there
+    (a substituted layout would wipe flash-backed state), modern cores
+    honor the override."""
+    assert _choose_ld_script("nodemcuv2", cv.Version(2, 3, 0)) is None
+    assert _choose_ld_script("nodemcuv2", cv.Version(2, 4, 2)) == "eagle.flash.4m.ld"
+    assert _choose_ld_script("d1_wroom_02", cv.Version(2, 7, 4)) == (
+        "eagle.flash.2m64.ld"
+    )
+    with pytest.raises(EsphomeError, match="cannot honor"):
+        _choose_ld_script("d1_wroom_02", cv.Version(2, 4, 2))

tests/unit_tests/components/esp8266/test_build_surgery.py

@@ -0,0 +1,145 @@
+"""Tests for the linker-script surgery shared with the native toolchain."""
+
+from __future__ import annotations
+
+import importlib.util
+from pathlib import Path
+import sys
+
+import pytest
+
+from esphome.components.esp8266 import build_surgery
+from esphome.components.esp8266.boards import BOARDS, ESP8266_BOARD_BUILD
+from esphome.components.esp8266.build_surgery import (
+    RATETABLE_RULE,
+    apply_testing_memory_patches,
+    relocate_ratetable,
+    segment_length,
+)
+
+_COMMON_LD_SNIPPET = """\
+  .dport0.data : ALIGN(4)
+  {
+    _dport0_data_start = ABSOLUTE(.);
+  } >dport0_0_seg :dport0_0_phdr
+  .data : ALIGN(4)
+  {
+    _data_start = ABSOLUTE(.);
+    *(.data)
+  } >dram0_0_seg :dram0_0_phdr
+"""
+
+# Shaped like the real SDK flash ld scripts: no iram1_0_seg (that lives in
+# the generated common ld only)
+_FLASH_LD_SNIPPET = """\
+MEMORY
+{
+  dport0_0_seg :                        org = 0x3FF00000, len = 0x10
+  dram0_0_seg :                         org = 0x3FFE8000, len = 0x14000
+  irom0_0_seg :                         org = 0x40201010, len = 0xfeff0
+}
+"""
+
+# Shaped like the preprocessed common ld: MMU_IRAM_SIZE expands with a ul
+# suffix the patcher must leave in place
+_COMMON_LD_MEMORY_SNIPPET = """\
+MEMORY
+{
+  iram1_0_seg :                         org = 0x40100000, len = 0x8000ul
+}
+"""
+
+
+def test_relocate_ratetable_inserts_after_data_start() -> None:
+    patched = relocate_ratetable(_COMMON_LD_SNIPPET)
+    assert RATETABLE_RULE in patched
+    # Inserted after the .data section's anchor, not the .dport0.data one
+    # (whose closing brace bounds the decoy block)
+    assert RATETABLE_RULE not in patched[: patched.index("} >dport0_0_seg")]
+    assert patched.index(RATETABLE_RULE) < patched.index("*(.data)")
+    # Idempotent on an already-patched script
+    assert relocate_ratetable(patched) == patched
+
+
+def test_relocate_ratetable_requires_anchor() -> None:
+    with pytest.raises(RuntimeError, match="_data_start"):
+        relocate_ratetable("SECTIONS { }")
+
+
+def test_testing_memory_patches_enlarge_segments() -> None:
+    patched = apply_testing_memory_patches(
+        _FLASH_LD_SNIPPET, ("dram0_0_seg", "irom0_0_seg")
+    )
+    assert segment_length(patched, "dram0_0_seg") == 0x200000
+    assert segment_length(patched, "irom0_0_seg") == 0x2000000
+    # Untouched segments keep their sizes
+    assert segment_length(patched, "dport0_0_seg") == 0x10
+
+
+def test_testing_memory_patches_keep_ul_suffix() -> None:
+    """The common ld's preprocessed sizes carry a ul suffix; the patch must
+    replace only the hex digits, as testing_mode.py.script does."""
+    patched = apply_testing_memory_patches(_COMMON_LD_MEMORY_SNIPPET, ("iram1_0_seg",))
+    assert "len = 0x200000ul" in patched
+    assert segment_length(patched, "iram1_0_seg") == 0x200000
+
+
+def test_segment_length_requires_whole_name() -> None:
+    """A name must match its own line, never inside a longer segment name."""
+    assert segment_length(_FLASH_LD_SNIPPET, "ram0_0_seg") is None
+
+
+def test_testing_memory_patches_unknown_segment_raises() -> None:
+    with pytest.raises(RuntimeError, match="Unknown testing-mode segment"):
+        apply_testing_memory_patches("MEMORY { }", ("bogus_seg",))
+
+
+def test_segment_length() -> None:
+    assert segment_length(_FLASH_LD_SNIPPET, "irom0_0_seg") == 0xFEFF0
+    assert segment_length(_FLASH_LD_SNIPPET, "missing_seg") is None
+
+
+def test_testing_memory_patches_missing_segment_raises() -> None:
+    """A named segment the patch could not find raises instead of silently
+    keeping the real memory limits."""
+    with pytest.raises(RuntimeError, match="dram0_0_seg"):
+        apply_testing_memory_patches("MEMORY { }", ("dram0_0_seg",))
+
+
+def test_board_build_covers_every_board() -> None:
+    """Every supported board has native build metadata (the table may carry
+    extras that BOARDS does not expose)."""
+    assert set(BOARDS) <= set(ESP8266_BOARD_BUILD)
+
+
+def test_surgery_fingerprint_is_stable_and_sensitive(tmp_path) -> None:
+    """The properties the linker-script cache depends on: the fingerprint is
+    stable across calls and changes when the module's source changes."""
+
+    first = build_surgery.surgery_fingerprint()
+    assert first == build_surgery.surgery_fingerprint()
+    assert len(first) == 64
+    int(first, 16)  # sha256 hex digest
+
+    # A modified copy of the module must fingerprint differently
+    copy = tmp_path / "build_surgery_variant.py"
+    copy.write_text(
+        Path(build_surgery.__file__).read_text(encoding="utf-8")
+        + "\nEXTRA_BEHAVIORAL_INPUT = 1\n",
+        encoding="utf-8",
+    )
+    spec = importlib.util.spec_from_file_location("build_surgery_variant", copy)
+    variant = importlib.util.module_from_spec(spec)
+    sys.modules[spec.name] = variant
+    try:
+        spec.loader.exec_module(variant)
+        assert variant.surgery_fingerprint() != first
+    finally:
+        del sys.modules[spec.name]
+
+
+def test_testing_memory_patches_present_but_unselected_raises() -> None:
+    """A known segment left off the caller's list must fail, not silently
+    keep its real memory limit."""
+    with pytest.raises(RuntimeError, match="not selected"):
+        apply_testing_memory_patches(_FLASH_LD_SNIPPET, ("dram0_0_seg",))