refactor(core): introduce "n4w1" feature in SConscript

diff --git a/core/Makefile b/core/Makefile
index 2ce03a58..a1b2275d 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -50,6 +50,7 @@ STORAGE_INSECURE_TESTING_MODE ?= 0
 UI_PERFORMANCE_OVERLAY ?= 0
 DBG_CONSOLE ?=
 EXTAPP_SUPPORT ?= 0
+N4W1 ?= 0
 
 # If set, VCP writes will be blocking, in order to allow reliable debug data transmission over VCP.
 # Disabled by default, to prevent debug firmware from getting stuck while writing log messages (if the host is not reading them).
@@ -147,7 +148,8 @@ SCONS_VARS = \
 	UI_PERFORMANCE_OVERLAY="$(UI_PERFORMANCE_OVERLAY)" \
 	BLOCK_ON_VCP="$(BLOCK_ON_VCP)" \
 	DBG_CONSOLE="$(DBG_CONSOLE)" \
-	EXTAPP_SUPPORT="$(EXTAPP_SUPPORT)"
+	EXTAPP_SUPPORT="$(EXTAPP_SUPPORT)" \
+	N4W1="$(N4W1)"
 
 ifdef DISABLE_OPTIGA
 SCONS_VARS += DISABLE_OPTIGA="$(DISABLE_OPTIGA)"
diff --git a/core/SConscript.firmware b/core/SConscript.firmware
index a579e003..d9cf493f 100644
--- a/core/SConscript.firmware
+++ b/core/SConscript.firmware
@@ -28,6 +28,7 @@ BLOCK_ON_VCP = ARGUMENTS.get('BLOCK_ON_VCP', '0') == '1'
 UI_PERFORMANCE_OVERLAY = ARGUMENTS.get('UI_PERFORMANCE_OVERLAY', '0') == '1'
 DBG_CONSOLE = ARGUMENTS.get('DBG_CONSOLE', '')
 EXTAPP_SUPPORT = ARGUMENTS.get('EXTAPP_SUPPORT', '0') == '1'
+N4W1 = ARGUMENTS.get('N4W1', '0') == '1'
 
 STORAGE_INSECURE_TESTING_MODE = ARGUMENTS.get('STORAGE_INSECURE_TESTING_MODE', '0') == '1'
 if STORAGE_INSECURE_TESTING_MODE and PRODUCTION:
@@ -97,6 +98,10 @@ if DBG_CONSOLE != "":
 if TREZOR_MODEL in ['T3W1'] and EXTAPP_SUPPORT:
     FEATURES_WANTED += ["app_loading"]
 
+if N4W1:
+    assert PYOPT == "0", "N4W1 requires PYOPT=0"
+    FEATURES_WANTED += ["n4w1"]
+
 CCFLAGS_MOD = ''
 CPPPATH_MOD = []
 CPPDEFINES_MOD = []
@@ -486,6 +491,7 @@ SDCARD = ('sd_card' in FEATURES_AVAILABLE)
 OPTIGA = ('optiga' in FEATURES_AVAILABLE)
 SERIAL_NUMBER = ('serial_number' in FEATURES_AVAILABLE)
 BACKLIGHT = ('backlight' in FEATURES_AVAILABLE)
+N4W1 = ('n4w1' in FEATURES_AVAILABLE)
 
 env.Tool('micropython')
 
@@ -740,7 +746,7 @@ if FROZEN:
         )
     ))
     if PYOPT == '0':
-        exclude_n4w1 = [SOURCE_PY_DIR + 'apps/debug/n4w1_mock.py'] if TREZOR_MODEL != "T3W1" else []
+        exclude_n4w1 = [SOURCE_PY_DIR + 'apps/debug/n4w1_mock.py'] if not N4W1 else []
         SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'apps/debug/*.py', exclude=exclude_n4w1))
     SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'apps/homescreen/*.py',
         exclude=[
@@ -857,6 +863,7 @@ if FROZEN:
         ui_layout=ui.get_ui_layout(TREZOR_MODEL),
         thp=THP,
         power_manager='power_manager' in FEATURES_AVAILABLE,
+        n4w1=N4W1,
         include_source_lines=MICROPY_ENABLE_SOURCE_LINE,
     )
 
diff --git a/core/SConscript.unix b/core/SConscript.unix
index 73dd6bf3..468089db 100644
--- a/core/SConscript.unix
+++ b/core/SConscript.unix
@@ -20,6 +20,7 @@ RASPI = os.getenv('TREZOR_EMULATOR_RASPI') == '1'
 MICROPY_ENABLE_SOURCE_LINE = ARGUMENTS.get('MICROPY_ENABLE_SOURCE_LINE', '1') == '1'
 DBG_CONSOLE = ARGUMENTS.get('DBG_CONSOLE', '')
 EXTAPP_SUPPORT = ARGUMENTS.get('EXTAPP_SUPPORT', '0') == '1'
+N4W1 = ARGUMENTS.get('N4W1', '0') == '1'
 
 
 if DEBUGLINK or PYOPT == '0':
@@ -68,6 +69,10 @@ if not DISABLE_TROPIC:
 if TREZOR_MODEL in ['T3W1'] and EXTAPP_SUPPORT:
     FEATURES_WANTED += ["app_loading"]
 
+if N4W1:
+    assert PYOPT == "0", "N4W1 requires PYOPT=0"
+    FEATURES_WANTED += ["n4w1"]
+
 if not models.has_emulator(TREZOR_MODEL):
     # skip unix build
     env = Environment()
@@ -469,6 +474,7 @@ SDCARD = ('sd_card' in FEATURES_AVAILABLE)
 OPTIGA = ('optiga' in FEATURES_AVAILABLE)
 SERIAL_NUMBER = ('serial_number' in FEATURES_AVAILABLE)
 BACKLIGHT = ('backlight' in FEATURES_AVAILABLE)
+N4W1 = ('n4w1' in FEATURES_AVAILABLE)
 
 env.Tool('micropython')
 
@@ -755,7 +761,7 @@ if FROZEN:
         )
     ))
     if PYOPT == '0':
-        exclude_n4w1 = [SOURCE_PY_DIR + 'apps/debug/n4w1_mock.py'] if TREZOR_MODEL != "T3W1" else []
+        exclude_n4w1 = [SOURCE_PY_DIR + 'apps/debug/n4w1_mock.py'] if not N4W1 else []
         SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'apps/debug/*.py', exclude=exclude_n4w1))
     SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'apps/homescreen/*.py',
         exclude=[
@@ -876,6 +882,7 @@ if FROZEN:
         ui_layout=ui.get_ui_layout(TREZOR_MODEL),
         thp=THP,
         power_manager='power_manager' in FEATURES_AVAILABLE,
+        n4w1=N4W1,
         include_source_lines=MICROPY_ENABLE_SOURCE_LINE,
     )
 
diff --git a/core/embed/rust/Cargo.toml b/core/embed/rust/Cargo.toml
index 8c46472f..31170e5c 100644
--- a/core/embed/rust/Cargo.toml
+++ b/core/embed/rust/Cargo.toml
@@ -56,6 +56,7 @@ tropic = []
 serial_number = []
 storage = []
 telemetry = []
+n4w1 = []
 translations = ["crypto"]
 secmon_layout = []
 dbg_console = []
diff --git a/core/embed/upymod/modtrezorutils/modtrezorutils.c b/core/embed/upymod/modtrezorutils/modtrezorutils.c
index ca1b643b..119fac04 100644
--- a/core/embed/upymod/modtrezorutils/modtrezorutils.c
+++ b/core/embed/upymod/modtrezorutils/modtrezorutils.c
@@ -798,6 +798,8 @@ STATIC const mp_obj_tuple_t mod_trezorutils_version_obj = {
 /// """Whether the firmware supports loading 3rd-party applications."""
 /// USE_TELEMETRY: bool
 /// """Whether a telemetry is supported."""
+/// USE_N4W1: bool
+/// """Whether N4W1 is supported."""
 /// MODEL: str
 /// """Model name."""
 /// MODEL_FULL_NAME: str
@@ -909,6 +911,11 @@ STATIC const mp_rom_map_elem_t mp_module_trezorutils_globals_table[] = {
 #else
     {MP_ROM_QSTR(MP_QSTR_USE_SERIAL_NUMBER), mp_const_false},
 #endif
+#if USE_N4W1
+    {MP_ROM_QSTR(MP_QSTR_USE_N4W1), mp_const_true},
+#else
+    {MP_ROM_QSTR(MP_QSTR_USE_N4W1), mp_const_false},
+#endif
 #if !PYOPT
 #if LOG_STACK_USAGE
     {MP_ROM_QSTR(MP_QSTR_zero_unused_stack),
diff --git a/core/mocks/generated/trezorutils.pyi b/core/mocks/generated/trezorutils.pyi
index 29c48f8c..d2d6ada4 100644
--- a/core/mocks/generated/trezorutils.pyi
+++ b/core/mocks/generated/trezorutils.pyi
@@ -280,6 +280,8 @@ USE_APP_LOADING: bool
 """Whether the firmware supports loading 3rd-party applications."""
 USE_TELEMETRY: bool
 """Whether a telemetry is supported."""
+USE_N4W1: bool
+"""Whether N4W1 is supported."""
 MODEL: str
 """Model name."""
 MODEL_FULL_NAME: str
diff --git a/core/site_scons/models/T3W1/emulator.py b/core/site_scons/models/T3W1/emulator.py
index c15f1de4..171b2d76 100644
--- a/core/site_scons/models/T3W1/emulator.py
+++ b/core/site_scons/models/T3W1/emulator.py
@@ -159,4 +159,8 @@ def configure(
         defines += [("USE_SERIAL_NUMBER", "1")]
         features_available.append("serial_number")
 
+    if "n4w1" in features_wanted:
+        defines += [("USE_N4W1", "1")]
+        features_available.append("n4w1")
+
     return features_available
diff --git a/core/site_scons/models/T3W1/trezor_t3w1_revA.py b/core/site_scons/models/T3W1/trezor_t3w1_revA.py
index 117cbed7..f9728c5b 100644
--- a/core/site_scons/models/T3W1/trezor_t3w1_revA.py
+++ b/core/site_scons/models/T3W1/trezor_t3w1_revA.py
@@ -319,6 +319,10 @@ def configure(
         defines += [("USE_SERIAL_NUMBER", "1")]
         features_available.append("serial_number")
 
+    if "n4w1" in features_wanted:
+        defines += [("USE_N4W1", "1")]
+        features_available.append("n4w1")
+
     ENV["LINKER_SCRIPT"] = linker_script
     ENV["MEMORY_LAYOUT"] = memory_layout
 
diff --git a/core/site_scons/models/T3W1/trezor_t3w1_revB.py b/core/site_scons/models/T3W1/trezor_t3w1_revB.py
index fcd4e756..8b99c0e7 100644
--- a/core/site_scons/models/T3W1/trezor_t3w1_revB.py
+++ b/core/site_scons/models/T3W1/trezor_t3w1_revB.py
@@ -333,6 +333,10 @@ def configure(
         defines += [("USE_SERIAL_NUMBER", "1")]
         features_available.append("serial_number")
 
+    if "n4w1" in features_wanted:
+        defines += [("USE_N4W1", "1")]
+        features_available.append("n4w1")
+
     ENV["LINKER_SCRIPT"] = linker_script
     ENV["MEMORY_LAYOUT"] = memory_layout
 
diff --git a/core/site_scons/models/T3W1/trezor_t3w1_revC.py b/core/site_scons/models/T3W1/trezor_t3w1_revC.py
index 372ac661..30f0113b 100644
--- a/core/site_scons/models/T3W1/trezor_t3w1_revC.py
+++ b/core/site_scons/models/T3W1/trezor_t3w1_revC.py
@@ -331,6 +331,10 @@ def configure(
         defines += [("USE_SERIAL_NUMBER", "1")]
         features_available.append("serial_number")
 
+    if "n4w1" in features_wanted:
+        defines += [("USE_N4W1", "1")]
+        features_available.append("n4w1")
+
     ENV["LINKER_SCRIPT"] = linker_script
     ENV["MEMORY_LAYOUT"] = memory_layout
 
diff --git a/core/site_scons/site_tools/micropython/__init__.py b/core/site_scons/site_tools/micropython/__init__.py
index c05da6aa..df89d0a2 100644
--- a/core/site_scons/site_tools/micropython/__init__.py
+++ b/core/site_scons/site_tools/micropython/__init__.py
@@ -62,6 +62,7 @@ def generate(env):
         layout_eckhart = env["ui_layout"] == "UI_LAYOUT_ECKHART"
         thp = env["thp"]
         power_manager = env["power_manager"]
+        n4w1 = env["n4w1"]
         include_source_lines = env["include_source_lines"]
         interim = f"{target[:-4]}.i"  # replace .mpy with .i
         sed_scripts = [
@@ -78,6 +79,7 @@ def generate(env):
             rf"-e 's/utils\.USE_TOUCH/{touch}/g'",
             rf"-e 's/utils\.USE_THP/{thp}/g'",
             rf"-e 's/utils\.USE_POWER_MANAGER/{power_manager}/g'",
+            rf"-e 's/utils\.USE_N4W1/{n4w1}/g'",
             r"-e 's/if TYPE_CHECKING/if False/'",
             r"-e 's/import typing/# &/'",
             r"-e '/from typing import (/,/^[[:space:]]*)/ {s/^/# /; }'",
diff --git a/core/src/apps/debug/__init__.py b/core/src/apps/debug/__init__.py
index fcae69e1..fc31fabe 100644
--- a/core/src/apps/debug/__init__.py
+++ b/core/src/apps/debug/__init__.py
@@ -448,7 +448,7 @@ if __debug__:
         finally:
             raise RestartEventLoop
 
-    if utils.INTERNAL_MODEL == "T3W1":  # TODO utils.USE_N4W1
+    if utils.USE_N4W1:
 
         async def dispatch_DebugLinkConnected(msg: DebugLinkN4W1Connected) -> Success:
             """Exchange a sequence of N4W1 messages."""
@@ -577,7 +577,7 @@ if __debug__:
         MessageType.WipeDevice: dispatch_WipeDevice,
     }
 
-    if utils.INTERNAL_MODEL == "T3W1":  # TODO utils.USE_N4W1
+    if utils.USE_N4W1:
         WORKFLOW_HANDLERS[MessageType.DebugLinkN4W1Connected] = (
             dispatch_DebugLinkConnected
         )
diff --git a/core/src/trezor/utils.py b/core/src/trezor/utils.py
index 6a495f2e..f416e763 100644
--- a/core/src/trezor/utils.py
+++ b/core/src/trezor/utils.py
@@ -27,6 +27,7 @@ from trezorutils import (  # noqa: F401
     USE_BUTTON,
     USE_DBG_CONSOLE,
     USE_HAPTIC,
+    USE_N4W1,
     USE_NRF,
     USE_OPTIGA,
     USE_POWER_MANAGER,