feat(core): Implement SetBusy message.

core/.changelog.d/2445.added

@@ -0,0 +1 @@
+Support SetBusy message.

core/src/all_modules.py

@@ -351,6 +351,8 @@ apps.debug.load_device
 import apps.debug.load_device
 apps.homescreen
 import apps.homescreen
+apps.homescreen.busyscreen
+import apps.homescreen.busyscreen
 apps.homescreen.homescreen
 import apps.homescreen.homescreen
 apps.homescreen.lockscreen

core/src/apps/base.py

@@ -20,9 +20,26 @@ if TYPE_CHECKING:
         Ping,
         DoPreauthorized,
         CancelAuthorization,
+        SetBusy,
     )
 
 
+def busy_expiry_ms() -> int:
+    """
+    Returns the time left until the busy state expires or 0 if the device is not in the busy state.
+    """
+
+    busy_deadline_bytes = storage.cache.get(storage.cache.APP_COMMON_BUSY_DEADLINE_MS)
+    if busy_deadline_bytes is None:
+        return 0
+
+    import utime
+
+    busy_deadline_ms = int.from_bytes(busy_deadline_bytes, "big")
+    expiry_ms = utime.ticks_diff(busy_deadline_ms, utime.ticks_ms())
+    return expiry_ms if expiry_ms > 0 else 0
+
+
 def get_features() -> Features:
     import storage.recovery
     import storage.sd_salt
@@ -47,6 +64,7 @@ def get_features() -> Features:
         label=storage.device.get_label(),
         pin_protection=config.has_pin(),
         unlocked=config.is_unlocked(),
+        busy=busy_expiry_ms() > 0,
     )
 
     if utils.BITCOIN_ONLY:
@@ -145,6 +163,24 @@ async def handle_LockDevice(ctx: wire.Context, msg: LockDevice) -> Success:
     return Success()
 
 
+async def handle_SetBusy(ctx: wire.Context, msg: SetBusy) -> Success:
+    if not storage.device.is_initialized():
+        raise wire.NotInitialized("Device is not initialized")
+
+    if msg.expiry_ms:
+        import utime
+
+        deadline = utime.ticks_add(utime.ticks_ms(), msg.expiry_ms)
+        storage.cache.set(
+            storage.cache.APP_COMMON_BUSY_DEADLINE_MS, deadline.to_bytes(4, "big")
+        )
+    else:
+        storage.cache.delete(storage.cache.APP_COMMON_BUSY_DEADLINE_MS)
+    set_homescreen()
+    workflow.close_others()
+    return Success()
+
+
 async def handle_EndSession(ctx: wire.Context, msg: EndSession) -> Success:
     storage.cache.end_current_session()
     return Success()
@@ -200,13 +236,20 @@ ALLOW_WHILE_LOCKED = (
     MessageType.LockDevice,
     MessageType.DoPreauthorized,
     MessageType.WipeDevice,
+    MessageType.SetBusy,
 )
 
 
 def set_homescreen() -> None:
     import storage.recovery
+    import storage  # workaround for https://github.com/microsoft/pyright/issues/2685
 
-    if not config.is_unlocked():
+    if storage.cache.is_set(storage.cache.APP_COMMON_BUSY_DEADLINE_MS):
+        from apps.homescreen.busyscreen import busyscreen
+
+        workflow.set_default(busyscreen)
+
+    elif not config.is_unlocked():
         from apps.homescreen.lockscreen import lockscreen
 
         workflow.set_default(lockscreen)
@@ -296,6 +339,7 @@ def boot() -> None:
     workflow_handlers.register(
         MessageType.CancelAuthorization, handle_CancelAuthorization
     )
+    workflow_handlers.register(MessageType.SetBusy, handle_SetBusy)
 
     reload_settings_from_storage()
     if config.is_unlocked():

core/src/apps/homescreen/busyscreen.py

@@ -0,0 +1,29 @@
+import storage.cache
+from trezor import loop, ui
+from trezor.ui.layouts import draw_simple_text
+
+from apps.base import busy_expiry_ms, set_homescreen
+
+from . import HomescreenBase
+
+
+async def busyscreen() -> None:
+    await Busyscreen()
+
+
+class Busyscreen(HomescreenBase):
+    RENDER_INDICATOR = storage.cache.BUSYSCREEN_ON
+
+    def create_tasks(self) -> tuple[loop.AwaitableTask, ...]:
+        return self.handle_rendering(), self.handle_input(), self.handle_expiry()
+
+    def handle_expiry(self) -> loop.Task:  # type: ignore [awaitable-is-generator]
+        yield loop.sleep(busy_expiry_ms())
+        storage.cache.delete(storage.cache.APP_COMMON_BUSY_DEADLINE_MS)
+        set_homescreen()
+        raise ui.Result(None)
+
+    def do_render(self) -> None:
+        draw_simple_text(
+            "Please wait", "CoinJoin in progress.\n\nDo not disconnect your\nTrezor."
+        )

core/src/storage/cache.py

@@ -30,6 +30,7 @@ APP_COMMON_SEED_WITHOUT_PASSPHRASE = 0 | _SESSIONLESS_FLAG
 APP_COMMON_SAFETY_CHECKS_TEMPORARY = 1 | _SESSIONLESS_FLAG
 STORAGE_DEVICE_EXPERIMENTAL_FEATURES = 2 | _SESSIONLESS_FLAG
 APP_COMMON_REQUEST_PIN_LAST_UNLOCK = 3 | _SESSIONLESS_FLAG
+APP_COMMON_BUSY_DEADLINE_MS = 4 | _SESSIONLESS_FLAG
 
 
 # === Homescreen storage ===
@@ -40,6 +41,7 @@ APP_COMMON_REQUEST_PIN_LAST_UNLOCK = 3 | _SESSIONLESS_FLAG
 # is still on. This way we can avoid unnecessary fadeins/fadeouts when a workflow ends.
 HOMESCREEN_ON = object()
 LOCKSCREEN_ON = object()
+BUSYSCREEN_ON = object()
 homescreen_shown: object | None = None
 
 
@@ -132,6 +134,7 @@ class SessionlessCache(DataCache):
             1,  # APP_COMMON_SAFETY_CHECKS_TEMPORARY
             1,  # STORAGE_DEVICE_EXPERIMENTAL_FEATURES
             4,  # APP_COMMON_REQUEST_PIN_LAST_UNLOCK
+            4,  # APP_COMMON_BUSY_DEADLINE_MS
         )
         super().__init__()