Make jump-to-bootloader.js wait for the UHK and time out.

usb/jump-to-bootloader.js

@@ -1,3 +1,26 @@
 #!/usr/bin/env node
 let uhk = require('./uhk');
-uhk.sendUsbPacket(new Buffer([uhk.usbCommands.jumpToBootloader]));
+
+let timeoutMs = 10000;
+let pollingIntervalMs = 100;
+
+console.log('Trying to jump to the bootloader...');
+setInterval(() => {
+    timeoutMs -= pollingIntervalMs;
+
+    if (uhk.getBootloaderDevice()) {
+        console.log('Bootloader is up');
+        process.exit(0);
+    }
+
+    if (timeoutMs <= 0) {
+        console.log("Couldn't jump to the bootloader");
+        process.exit(1);
+    }
+
+    if (uhk.getUhkDevice()) {
+        console.log('UHK found, jumping to bootloader');
+        uhk.sendUsbPacket(new Buffer([uhk.usbCommands.jumpToBootloader]));
+    }
+
+}, pollingIntervalMs);