Merge pull request #53 from balena-io-modules/aethernet/allow-custom-sb-assets

minor: allow passing custom assets to start SB protected CM4

Author: flowzone-app[bot]

.eslintrc.js

@@ -0,0 +1,8 @@
+module.exports = {
+  extends: ["./node_modules/@balena/lint/config/.eslintrc.js"],
+  root: true,
+  ignorePatterns: ["node_modules/"],
+  rules: {
+    "no-bitwise": "off",
+  },
+};

.gitignore

@@ -1,3 +1,4 @@
 build
 node_modules
 *.swo
+extra-folder*

lib/index.ts

@@ -7,7 +7,7 @@
 
 import { usb } from 'usb';
 import { OutEndpoint } from 'usb/dist/usb/endpoint';
-import { Interface } from 'usb/dist/usb/interface';
+import type { Interface } from 'usb/dist/usb/interface';
 import * as _debug from 'debug';
 import { EventEmitter } from 'events';
 import { readFile } from 'fs/promises';
@@ -340,27 +340,41 @@ const getDeviceId = (device: usb.Device): string => {
 	return `${device.busNumber}:${device.deviceAddress}`;
 };
 
-const safeReadFile = async (filename: string): Promise<Buffer | undefined> => {
+const getFileBuffer = async (
+	device: usb.Device,
+	filename: string,
+	extraFolder?: string,
+): Promise<Buffer | undefined> => {
 	try {
-		return await readFile(Path.join(__dirname, '..', 'blobs', filename));
+		if (extraFolder) {
+			const extraBuffer = await readFile(Path.join(extraFolder, filename));
+			if (extraBuffer !== undefined) {
+				debug(`Sending buffer from ${extraFolder}/${filename}`);
+				return extraBuffer;
+			}
+		}
 	} catch (e) {
 		// no data
 	}
-};
 
-const getFileBuffer = async (
-	device: usb.Device,
-	filename: string,
-): Promise<Buffer | undefined> => {
-	const folder =
-		device.deviceDescriptor.idProduct === USB_PRODUCT_ID_BCM2711_BOOT
-			? 'cm4'
-			: 'raspberrypi';
-	const buffer = await safeReadFile(Path.join(folder, filename));
-	if (buffer === undefined) {
-		debug("Can't read file", filename);
+	try {
+		const folder =
+			device.deviceDescriptor.idProduct === USB_PRODUCT_ID_BCM2711_BOOT
+				? 'cm4'
+				: 'raspberrypi';
+
+		const buffer = await readFile(
+			Path.join(__dirname, '..', 'blobs', folder, filename),
+		);
+
+		if (buffer === undefined) {
+			debug("Can't read file", filename);
+		}
+
+		return buffer;
+	} catch (e) {
+		// no data
 	}
-	return buffer;
 };
 
 /**
@@ -468,8 +482,12 @@ export class UsbbootScanner extends EventEmitter {
 	// So we keep track of attached devices ids in attachedDeviceIds to not run it twice.
 	private attachedDeviceIds = new Set<string>();
 
-	constructor() {
+	private extraFolder: string | undefined;
+
+	constructor(extraFolder?: string) {
 		super();
+		this.extraFolder = extraFolder;
+		debug(`Extra folder: ${extraFolder}`);
 		this.boundAttachDevice = this.attachDevice.bind(this);
 		this.boundDetachDevice = this.detachDevice.bind(this);
 	}
@@ -478,6 +496,7 @@ export class UsbbootScanner extends EventEmitter {
 		debug('Waiting for BCM2835/6/7/2711');
 
 		// Prepare already connected devices
+		// eslint-disable-next-line @typescript-eslint/no-floating-promises
 		usb.getDeviceList().map(this.boundAttachDevice);
 
 		// At this point all devices from `usg.getDeviceList()` above
@@ -488,8 +507,7 @@ export class UsbbootScanner extends EventEmitter {
 		// Watch for devices detaching
 		usb.on('detach', this.boundDetachDevice);
 
-		// ts-ignore because of a confusion between NodeJS.Timer and number
-		// @ts-ignore
+		// @ts-expect-error because of a confusion between NodeJS.Timer and number
 		this.interval = setInterval(() => {
 			// usb.getDeviceList().forEach(this.boundAttachDevice);
 		}, POLLING_INTERVAL_MS);
@@ -548,7 +566,7 @@ export class UsbbootScanner extends EventEmitter {
 
 		const usbbootDevice = this.get(device);
 		let forceSecondstage = false;
-		if (device.deviceDescriptor.iSerialNumber == usbbootDevice?.last_serial) {
+		if (device.deviceDescriptor.iSerialNumber === usbbootDevice?.last_serial) {
 			if (usbbootDevice.step > 0) {
 				forceSecondstage = true;
 			}
@@ -565,23 +583,29 @@ export class UsbbootScanner extends EventEmitter {
 		if (!isUsbBootCapableUSBDevice$(device)) {
 			return;
 		}
-		debug('Found serial number', device.deviceDescriptor.iSerialNumber, `${forceSecondstage ? " => Forced second stage" : ""}`);
+		debug(
+			'Found serial number',
+			device.deviceDescriptor.iSerialNumber,
+			`${forceSecondstage ? ' => Forced second stage' : ''}`,
+		);
 		debug('port id', devicePortId(device));
 		try {
 			const { endpoint } = initializeDevice(device);
 			// cm: 0; cm4: 3
 			if (
 				(device.deviceDescriptor.iSerialNumber === 0 ||
-				device.deviceDescriptor.iSerialNumber === 3) && !forceSecondstage
+					device.deviceDescriptor.iSerialNumber === 3) &&
+				!forceSecondstage
 			) {
 				debug('Sending bootcode.bin', devicePortId(device));
 				this.step(device, 0);
 				await secondStageBoot(device, endpoint);
 				// The device will now detach and reattach with iSerialNumber 1.
 				// This takes approximately 1.5 seconds
 			} else {
+				const extraFolder = this.extraFolder;
 				debug('Second stage boot server', devicePortId(device));
-				await this.fileServer(device, endpoint, 2);
+				await this.fileServer(device, endpoint, 2, extraFolder);
 			}
 			device.close();
 		} catch (error) {
@@ -623,7 +647,9 @@ export class UsbbootScanner extends EventEmitter {
 		device: usb.Device,
 		endpoint: OutEndpoint,
 		step: number,
+		extraFolder?: string,
 	) {
+		// eslint-disable-next-line no-constant-condition
 		while (true) {
 			let data;
 			try {
@@ -652,7 +678,11 @@ export class UsbbootScanner extends EventEmitter {
 				message.command === FileMessageCommand.GetFileSize ||
 				message.command === FileMessageCommand.ReadFile
 			) {
-				const buffer = await getFileBuffer(device, message.filename);
+				const buffer = await getFileBuffer(
+					device,
+					message.filename,
+					extraFolder,
+				);
 				if (buffer === undefined) {
 					debug(`Couldn't find ${message.filename}`, devicePortId(device));
 					await sendSize(device, 0);

lib/main.ts

@@ -1,8 +1,22 @@
+import { argv } from 'process';
+import * as fs from 'fs';
 import type { UsbbootDevice } from './';
 import { UsbbootScanner } from './';
 
+const usbBootExtraFolder = argv.length > 2 ? isValidPath(argv[2]) : undefined;
+
+function isValidPath(path: string) {
+	if (fs.existsSync(path)) {
+		return path;
+	} else {
+		throw new Error(
+			'Invalid path provided as argument. Please provide a valid path if you want to use alternative boot assets.',
+		);
+	}
+}
+
 const main = () => {
-	const scanner = new UsbbootScanner();
+	const scanner = new UsbbootScanner(usbBootExtraFolder);
 	scanner.on('attach', (usbbootDevice: UsbbootDevice) => {
 		console.log('device attached', usbbootDevice.portId);
 		usbbootDevice.on('progress', (progress: number) => {