firmware: Firmware must be sector size multiple.

If the EV3 firmware size is not a multiple of the sector size,
the flashing process will hang. Raise an error if this happens.

Author: jaguilar

src/firmware/actions.ts

@@ -47,6 +47,8 @@ export enum FailToFinishReasonType {
     FailedToCompile = 'flashFirmware.failToFinish.reason.failedToCompile',
     /** The combined firmware-base.bin and main.mpy are too big. */
     FirmwareSize = 'flashFirmware.failToFinish.reason.firmwareSize',
+    /** The firmware has the wrong format (e.g. is not a multiple of sector size). */
+    FirmwareSizeNotMultipleOfSector = 'flashFirmware.failToFinish.reason.firmwareSizeNotMultipleOfSector',
     /** An unexpected error occurred. */
     Unknown = 'flashFirmware.failToFinish.reason.unknown',
 }
@@ -94,6 +96,9 @@ export type FailToFinishReasonBadMetadata =
 export type FailToFinishReasonFirmwareSize =
     Reason<FailToFinishReasonType.FirmwareSize>;
 
+export type FailToFinishReasonFirmwareFormat =
+    Reason<FailToFinishReasonType.FirmwareSizeNotMultipleOfSector>;
+
 export type FailToFinishReasonFailedToCompile =
     Reason<FailToFinishReasonType.FailedToCompile>;
 
@@ -114,6 +119,7 @@ export type FailToFinishReason =
     | FailToFinishReasonBadMetadata
     | FailToFinishReasonFirmwareSize
     | FailToFinishReasonFailedToCompile
+    | FailToFinishReasonFirmwareFormat
     | FailToFinishReasonUnknown;
 
 // High-level bootloader actions.

src/notifications/i18n.ts

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: MIT
-// Copyright (c) 2020-2022 The Pybricks Authors
+// Copyright (c) 2020-2025 The Pybricks Authors
 //
 // Notification translation keys.
 
@@ -35,6 +35,7 @@ export enum I18nId {
     FlashFirmwareBadMetadata = 'flashFirmware.badMetadata',
     FlashFirmwareCompileError = 'flashFirmware.compileError',
     FlashFirmwareSizeTooBig = 'flashFirmware.sizeTooBig',
+    FlashFirmwareSizeNotMultipleOfSector = 'flashFirmware.sizeNotMultipleOfSector',
     FlashFirmwareUnexpectedError = 'flashFirmware.unexpectedError',
     ServiceWorkerUpdateMessage = 'serviceWorker.update.message',
     ServiceWorkerUpdateAction = 'serviceWorker.update.action',

src/notifications/sagas.test.ts

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: MIT
-// Copyright (c) 2021-2023 The Pybricks Authors
+// Copyright (c) 2021-2025 The Pybricks Authors
 
 import type { ToastOptions, Toaster } from '@blueprintjs/core';
 import { FirmwareReaderError, FirmwareReaderErrorCode } from '@pybricks/firmware';
@@ -95,6 +95,7 @@ test.each([
     ),
     didFailToFinish(FailToFinishReasonType.FailedToCompile),
     didFailToFinish(FailToFinishReasonType.FirmwareSize),
+    didFailToFinish(FailToFinishReasonType.FirmwareSizeNotMultipleOfSector),
     didFailToFinish(FailToFinishReasonType.Unknown, new Error('test error')),
     appDidCheckForUpdate(false),
     fileStorageDidFailToInitialize(new Error('test error')),

src/notifications/sagas.ts

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: MIT
-// Copyright (c) 2020-2023 The Pybricks Authors
+// Copyright (c) 2020-2025 The Pybricks Authors
 
 // Saga for managing notifications (toasts)
 
@@ -225,6 +225,12 @@ function* showFlashFirmwareError(
         case FailToFinishReasonType.FailedToCompile:
             yield* showSingleton(Level.Error, I18nId.FlashFirmwareCompileError);
             break;
+        case FailToFinishReasonType.FirmwareSizeNotMultipleOfSector:
+            yield* showSingleton(
+                Level.Error,
+                I18nId.FlashFirmwareSizeNotMultipleOfSector,
+            );
+            break;
         case FailToFinishReasonType.FirmwareSize:
             yield* showSingleton(Level.Error, I18nId.FlashFirmwareSizeTooBig);
             break;

src/notifications/translations/en.json

@@ -33,7 +33,8 @@
         "badMetadata": "The firmware.metadata.json file contains missing or invalid entries. Fix it then try again.",
         "compileError": "The included main.py file could not be compiled. Fix it then try again.",
         "sizeTooBig": "The combined firmware and main.py are too big to fit in the flash memory.",
-        "unexpectedError": "Unexpected error while trying to install firmware: {errorMessage}"
+        "unexpectedError": "Unexpected error while trying to install firmware: {errorMessage}",
+        "sizeNotMultipleOfSector": "The firmware size is not a multiple of the flash memory sector size."
     },
     "mpy": {
         "error": "{errorMessage}"