diff --git a/ui.cpp b/ui.cpp
new file mode 100644
index 0000000..fd370a7
--- /dev/null
+++ b/ui.cpp
@@ -0,0 +1,222 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/input.h>
+#include <pthread.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <cutils/android_reboot.h>
+
+#include "common.h"
+#include "device.h"
+#include "minui/minui.h"
+#include "screen_ui.h"
+#include "ui.h"
+
+#define UI_WAIT_KEY_TIMEOUT_SEC    120
+
+// There's only (at most) one of these objects, and global callbacks
+// (for pthread_create, and the input event system) need to find it,
+// so use a global variable.
+static RecoveryUI* self = NULL;
+
+RecoveryUI::RecoveryUI() :
+    key_queue_len(0),
+    key_last_down(-1) {
+    pthread_mutex_init(&key_queue_mutex, NULL);
+    pthread_cond_init(&key_queue_cond, NULL);
+    self = this;
+}
+
+void RecoveryUI::Init() {
+    ev_init(input_callback, NULL);
+    pthread_create(&input_t, NULL, input_thread, NULL);
+}
+
+
+int RecoveryUI::input_callback(int fd, short revents, void* data)
+{
+    struct input_event ev;
+    int ret;
+
+    ret = ev_get_input(fd, revents, &ev);
+    if (ret)
+        return -1;
+
+    if (ev.type == EV_SYN) {
+        return 0;
+    } else if (ev.type == EV_REL) {
+        if (ev.code == REL_Y) {
+            // accumulate the up or down motion reported by
+            // the trackball.  When it exceeds a threshold
+            // (positive or negative), fake an up/down
+            // key event.
+            self->rel_sum += ev.value;
+            if (self->rel_sum > 3) {
+                self->process_key(KEY_DOWN, 1);   // press down key
+                self->process_key(KEY_DOWN, 0);   // and release it
+                self->rel_sum = 0;
+            } else if (self->rel_sum < -3) {
+                self->process_key(KEY_UP, 1);     // press up key
+                self->process_key(KEY_UP, 0);     // and release it
+                self->rel_sum = 0;
+            }
+        }
+    } else {
+        self->rel_sum = 0;
+    }
+
+    if (ev.type == EV_KEY && ev.code <= KEY_MAX)
+        self->process_key(ev.code, ev.value);
+
+    return 0;
+}
+
+// Process a key-up or -down event.  A key is "registered" when it is
+// pressed and then released, with no other keypresses or releases in
+// between.  Registered keys are passed to CheckKey() to see if it
+// should trigger a visibility toggle, an immediate reboot, or be
+// queued to be processed next time the foreground thread wants a key
+// (eg, for the menu).
+//
+// We also keep track of which keys are currently down so that
+// CheckKey can call IsKeyPressed to see what other keys are held when
+// a key is registered.
+//
+// updown == 1 for key down events; 0 for key up events
+void RecoveryUI::process_key(int key_code, int updown) {
+    bool register_key = false;
+
+    pthread_mutex_lock(&key_queue_mutex);
+    key_pressed[key_code] = updown;
+    if (updown) {
+        key_last_down = key_code;
+    } else {
+        if (key_last_down == key_code)
+            register_key = true;
+        key_last_down = -1;
+    }
+    pthread_mutex_unlock(&key_queue_mutex);
+
+    if (register_key) {
+        switch (CheckKey(key_code)) {
+          case RecoveryUI::TOGGLE:
+            ShowText(!IsTextVisible());
+            break;
+
+          case RecoveryUI::REBOOT:
+            android_reboot(ANDROID_RB_RESTART, 0, 0);
+            break;
+
+          case RecoveryUI::ENQUEUE:
+            pthread_mutex_lock(&key_queue_mutex);
+            const int queue_max = sizeof(key_queue) / sizeof(key_queue[0]);
+            if (key_queue_len < queue_max) {
+                key_queue[key_queue_len++] = key_code;
+                pthread_cond_signal(&key_queue_cond);
+            }
+            pthread_mutex_unlock(&key_queue_mutex);
+            break;
+        }
+    }
+}
+
+// Reads input events, handles special hot keys, and adds to the key queue.
+void* RecoveryUI::input_thread(void *cookie)
+{
+    for (;;) {
+        if (!ev_wait(-1))
+            ev_dispatch();
+    }
+    return NULL;
+}
+
+int RecoveryUI::WaitKey()
+{
+    pthread_mutex_lock(&key_queue_mutex);
+
+    // Time out after UI_WAIT_KEY_TIMEOUT_SEC, unless a USB cable is
+    // plugged in.
+    do {
+        struct timeval now;
+        struct timespec timeout;
+        gettimeofday(&now, NULL);
+        timeout.tv_sec = now.tv_sec;
+        timeout.tv_nsec = now.tv_usec * 1000;
+        timeout.tv_sec += UI_WAIT_KEY_TIMEOUT_SEC;
+
+        int rc = 0;
+        while (key_queue_len == 0 && rc != ETIMEDOUT) {
+            rc = pthread_cond_timedwait(&key_queue_cond, &key_queue_mutex,
+                                        &timeout);
+        }
+    } while (usb_connected() && key_queue_len == 0);
+
+    int key = -1;
+    if (key_queue_len > 0) {
+        key = key_queue[0];
+        memcpy(&key_queue[0], &key_queue[1], sizeof(int) * --key_queue_len);
+    }
+    pthread_mutex_unlock(&key_queue_mutex);
+    return key;
+}
+
+// Return true if USB is connected.
+bool RecoveryUI::usb_connected() {
+    int fd = open("/sys/class/android_usb/android0/state", O_RDONLY);
+    if (fd < 0) {
+        printf("failed to open /sys/class/android_usb/android0/state: %s\n",
+               strerror(errno));
+        return 0;
+    }
+
+    char buf;
+    /* USB is connected if android_usb state is CONNECTED or CONFIGURED */
+    int connected = (read(fd, &buf, 1) == 1) && (buf == 'C');
+    if (close(fd) < 0) {
+        printf("failed to close /sys/class/android_usb/android0/state: %s\n",
+               strerror(errno));
+    }
+    return connected;
+}
+
+bool RecoveryUI::IsKeyPressed(int key)
+{
+    pthread_mutex_lock(&key_queue_mutex);
+    int pressed = key_pressed[key];
+    pthread_mutex_unlock(&key_queue_mutex);
+    return pressed;
+}
+
+void RecoveryUI::FlushKeys() {
+    pthread_mutex_lock(&key_queue_mutex);
+    key_queue_len = 0;
+    pthread_mutex_unlock(&key_queue_mutex);
+}
+
+RecoveryUI::KeyAction RecoveryUI::CheckKey(int key) {
+    return RecoveryUI::ENQUEUE;
+}