diff --git a/Android.mk b/Android.mk
index 282862f..a94ecc6 100644
--- a/Android.mk
+++ b/Android.mk
@@ -4,12 +4,13 @@
 commands_recovery_local_path := $(LOCAL_PATH)
 
 LOCAL_SRC_FILES := \
-    recovery.c \
-    bootloader.c \
-    install.c \
-    roots.c \
-    ui.c \
-    verifier.c
+    recovery.cpp \
+    bootloader.cpp \
+    install.cpp \
+    roots.cpp \
+    ui.cpp \
+    screen_ui.cpp \
+    verifier.cpp
 
 LOCAL_MODULE := recovery
 
@@ -34,7 +35,7 @@
 LOCAL_MODULE_TAGS := eng
 
 ifeq ($(TARGET_RECOVERY_UI_LIB),)
-  LOCAL_SRC_FILES += default_recovery_ui.c
+  LOCAL_SRC_FILES += default_device.cpp
 else
   LOCAL_STATIC_LIBRARIES += $(TARGET_RECOVERY_UI_LIB)
 endif
@@ -50,7 +51,7 @@
 
 include $(CLEAR_VARS)
 
-LOCAL_SRC_FILES := verifier_test.c verifier.c
+LOCAL_SRC_FILES := verifier_test.cpp verifier.cpp ui.cpp
 
 LOCAL_MODULE := verifier_test
 
@@ -58,7 +59,7 @@
 
 LOCAL_MODULE_TAGS := tests
 
-LOCAL_STATIC_LIBRARIES := libmincrypt libcutils libstdc++ libc
+LOCAL_STATIC_LIBRARIES := libmincrypt libminui libcutils libstdc++ libc
 
 include $(BUILD_EXECUTABLE)
 
diff --git a/bootloader.c b/bootloader.cpp
similarity index 100%
rename from bootloader.c
rename to bootloader.cpp
diff --git a/bootloader.h b/bootloader.h
index 2e749aa..712aa1a 100644
--- a/bootloader.h
+++ b/bootloader.h
@@ -17,6 +17,10 @@
 #ifndef _RECOVERY_BOOTLOADER_H
 #define _RECOVERY_BOOTLOADER_H
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Bootloader Message
  *
  * This structure describes the content of a block in flash
@@ -47,4 +51,8 @@
 int get_bootloader_message(struct bootloader_message *out);
 int set_bootloader_message(const struct bootloader_message *in);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif
diff --git a/common.h b/common.h
index ef2fe9f..a1168cd 100644
--- a/common.h
+++ b/common.h
@@ -19,61 +19,12 @@
 
 #include <stdio.h>
 
-// Initialize the graphics system.
-void ui_init();
+#ifdef __cplusplus
+extern "C" {
+#endif
 
-// Use KEY_* codes from <linux/input.h> or KEY_DREAM_* from "minui/minui.h".
-int ui_wait_key();            // waits for a key/button press, returns the code
-int ui_key_pressed(int key);  // returns >0 if the code is currently pressed
-int ui_text_visible();        // returns >0 if text log is currently visible
-int ui_text_ever_visible();   // returns >0 if text log was ever visible
-void ui_show_text(int visible);
-void ui_clear_key_queue();
-
-// Write a message to the on-screen log shown with Alt-L (also to stderr).
-// The screen is small, and users may need to report these messages to support,
-// so keep the output short and not too cryptic.
-void ui_print(const char *fmt, ...) __attribute__((format(printf, 1, 2)));
-
-// Display some header text followed by a menu of items, which appears
-// at the top of the screen (in place of any scrolling ui_print()
-// output, if necessary).
-void ui_start_menu(char** headers, char** items, int initial_selection);
-// Set the menu highlight to the given index, and return it (capped to
-// the range [0..numitems).
-int ui_menu_select(int sel);
-// End menu mode, resetting the text overlay so that ui_print()
-// statements will be displayed.
-void ui_end_menu();
-
-// Set the icon (normally the only thing visible besides the progress bar).
-enum {
-  BACKGROUND_ICON_NONE,
-  BACKGROUND_ICON_INSTALLING,
-  BACKGROUND_ICON_ERROR,
-  NUM_BACKGROUND_ICONS
-};
-void ui_set_background(int icon);
-
-// Show a progress bar and define the scope of the next operation:
-//   portion - fraction of the progress bar the next operation will use
-//   seconds - expected time interval (progress bar moves at this minimum rate)
-void ui_show_progress(float portion, int seconds);
-void ui_set_progress(float fraction);  // 0.0 - 1.0 within the defined scope
-
-// Default allocation of progress bar segments to operations
-static const int VERIFICATION_PROGRESS_TIME = 60;
-static const float VERIFICATION_PROGRESS_FRACTION = 0.25;
-static const float DEFAULT_FILES_PROGRESS_FRACTION = 0.4;
-static const float DEFAULT_IMAGE_PROGRESS_FRACTION = 0.1;
-
-// Show a rotating "barberpole" for ongoing operations.  Updates automatically.
-void ui_show_indeterminate_progress();
-
-// Hide and reset the progress bar.
-void ui_reset_progress();
-
-#define LOGE(...) ui_print("E:" __VA_ARGS__)
+// TODO: restore ui_print for LOGE
+#define LOGE(...) fprintf(stdout, "E:" __VA_ARGS__)
 #define LOGW(...) fprintf(stdout, "W:" __VA_ARGS__)
 #define LOGI(...) fprintf(stdout, "I:" __VA_ARGS__)
 
@@ -107,26 +58,11 @@
                               // (that much).
 } Volume;
 
-typedef struct {
-    // number of frames in indeterminate progress bar animation
-    int indeterminate_frames;
-
-    // number of frames per second to try to maintain when animating
-    int update_fps;
-
-    // number of frames in installing animation.  may be zero for a
-    // static installation icon.
-    int installing_frames;
-
-    // the install icon is animated by drawing images containing the
-    // changing part over the base icon.  These specify the
-    // coordinates of the upper-left corner.
-    int install_overlay_offset_x;
-    int install_overlay_offset_y;
-
-} UIParameters;
-
 // fopen a file, mounting volumes and making parent dirs as necessary.
 FILE* fopen_path(const char *path, const char *mode);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif  // RECOVERY_COMMON_H
diff --git a/default_device.cpp b/default_device.cpp
new file mode 100644
index 0000000..265ed07
--- /dev/null
+++ b/default_device.cpp
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2009 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 <linux/input.h>
+
+#include "common.h"
+#include "device.h"
+#include "screen_ui.h"
+
+static const char* HEADERS[] = { "Volume up/down to move highlight;",
+                                 "enter button to select.",
+                                 "",
+                                 NULL };
+
+static const char* ITEMS[] =  {"reboot system now",
+                               "apply update from external storage",
+                               "apply update from cache",
+                               "wipe data/factory reset",
+                               "wipe cache partition",
+                               NULL };
+
+class DefaultUI : public ScreenRecoveryUI {
+  public:
+    virtual KeyAction CheckKey(int key) {
+        if (key == KEY_HOME) {
+            return TOGGLE;
+        }
+        return ENQUEUE;
+    }
+};
+
+class DefaultDevice : public Device {
+  public:
+    DefaultDevice() :
+        ui(new DefaultUI) {
+    }
+
+    RecoveryUI* GetUI() { return ui; }
+
+    int HandleMenuKey(int key, int visible) {
+        if (visible) {
+            switch (key) {
+              case KEY_DOWN:
+              case KEY_VOLUMEDOWN:
+                return kHighlightDown;
+
+              case KEY_UP:
+              case KEY_VOLUMEUP:
+                return kHighlightUp;
+
+              case KEY_ENTER:
+                return kInvokeItem;
+            }
+        }
+
+        return kNoAction;
+    }
+
+    BuiltinAction InvokeMenuItem(int menu_position) {
+        switch (menu_position) {
+          case 0: return REBOOT;
+          case 1: return APPLY_EXT;
+          case 2: return APPLY_CACHE;
+          case 3: return WIPE_DATA;
+          case 4: return WIPE_CACHE;
+          default: return NO_ACTION;
+        }
+    }
+
+    const char* const* GetMenuHeaders() { return HEADERS; }
+    const char* const* GetMenuItems() { return ITEMS; }
+
+  private:
+    RecoveryUI* ui;
+};
+
+Device* make_device() {
+    return new DefaultDevice();
+}
diff --git a/default_recovery_ui.c b/default_recovery_ui.c
deleted file mode 100644
index d56164e..0000000
--- a/default_recovery_ui.c
+++ /dev/null
@@ -1,73 +0,0 @@
-/*
- * Copyright (C) 2009 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 <linux/input.h>
-
-#include "recovery_ui.h"
-#include "common.h"
-
-char* MENU_HEADERS[] = { "Android system recovery utility",
-                         "",
-                         NULL };
-
-char* MENU_ITEMS[] = { "reboot system now",
-                       "apply update from external storage",
-                       "wipe data/factory reset",
-                       "wipe cache partition",
-                       "apply update from cache",
-                       NULL };
-
-void device_ui_init(UIParameters* ui_parameters) {
-}
-
-int device_recovery_start() {
-    return 0;
-}
-
-int device_toggle_display(volatile char* key_pressed, int key_code) {
-    return key_code == KEY_HOME;
-}
-
-int device_reboot_now(volatile char* key_pressed, int key_code) {
-    return 0;
-}
-
-int device_handle_key(int key_code, int visible) {
-    if (visible) {
-        switch (key_code) {
-            case KEY_DOWN:
-            case KEY_VOLUMEDOWN:
-                return HIGHLIGHT_DOWN;
-
-            case KEY_UP:
-            case KEY_VOLUMEUP:
-                return HIGHLIGHT_UP;
-
-            case KEY_ENTER:
-                return SELECT_ITEM;
-        }
-    }
-
-    return NO_ACTION;
-}
-
-int device_perform_action(int which) {
-    return which;
-}
-
-int device_wipe_data() {
-    return 0;
-}
diff --git a/device.h b/device.h
new file mode 100644
index 0000000..8096a8d
--- /dev/null
+++ b/device.h
@@ -0,0 +1,112 @@
+/*
+ * 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.
+ */
+
+#ifndef _RECOVERY_DEVICE_H
+#define _RECOVERY_DEVICE_H
+
+#include "ui.h"
+
+class Device {
+  public:
+    virtual ~Device() { }
+
+    // Called to obtain the UI object that should be used to display
+    // the recovery user interface for this device.  You should not
+    // have called Init() on the UI object already, the caller will do
+    // that after this method returns.
+    virtual RecoveryUI* GetUI() = 0;
+
+    // Called when recovery starts up (after the UI has been obtained
+    // and initialized and after the arguments have been parsed, but
+    // before anything else).
+    virtual void StartRecovery() { };
+
+    // enum KeyAction { NONE, TOGGLE, REBOOT };
+
+    // // Called in the input thread when a new key (key_code) is
+    // // pressed.  *key_pressed is an array of KEY_MAX+1 bytes
+    // // indicating which other keys are already pressed.  Return a
+    // // KeyAction to indicate action should be taken immediately.
+    // // These actions happen when recovery is not waiting for input
+    // // (eg, in the midst of installing a package).
+    // virtual KeyAction CheckImmediateKeyAction(volatile char* key_pressed, int key_code) = 0;
+
+    // Called from the main thread when recovery is at the main menu
+    // and waiting for input, and a key is pressed.  (Note that "at"
+    // the main menu does not necessarily mean the menu is visible;
+    // recovery will be at the main menu with it invisible after an
+    // unsuccessful operation [ie OTA package failure], or if recovery
+    // is started with no command.)
+    //
+    // key is the code of the key just pressed.  (You can call
+    // IsKeyPressed() on the RecoveryUI object you returned from GetUI
+    // if you want to find out if other keys are held down.)
+    //
+    // visible is true if the menu is visible.
+    //
+    // Return one of the defined constants below in order to:
+    //
+    //   - move the menu highlight (kHighlight{Up,Down})
+    //   - invoke the highlighted item (kInvokeItem)
+    //   - do nothing (kNoAction)
+    //   - invoke a specific action (a menu position: any non-negative number)
+    virtual int HandleMenuKey(int key, int visible) = 0;
+
+    enum BuiltinAction { NO_ACTION, REBOOT, APPLY_EXT, APPLY_CACHE,
+                         WIPE_DATA, WIPE_CACHE };
+
+    // Perform a recovery action selected from the menu.
+    // 'menu_position' will be the item number of the selected menu
+    // item, or a non-negative number returned from
+    // device_handle_key().  The menu will be hidden when this is
+    // called; implementations can call ui_print() to print
+    // information to the screen.  If the menu position is one of the
+    // builtin actions, you can just return the corresponding enum
+    // value.  If it is an action specific to your device, you
+    // actually perform it here and return NO_ACTION.
+    virtual BuiltinAction InvokeMenuItem(int menu_position) = 0;
+
+    static const int kNoAction = -1;
+    static const int kHighlightUp = -2;
+    static const int kHighlightDown = -3;
+    static const int kInvokeItem = -4;
+
+    // Called when we do a wipe data/factory reset operation (either via a
+    // reboot from the main system with the --wipe_data flag, or when the
+    // user boots into recovery manually and selects the option from the
+    // menu.)  Can perform whatever device-specific wiping actions are
+    // needed.  Return 0 on success.  The userdata and cache partitions
+    // are erased AFTER this returns (whether it returns success or not).
+    virtual int WipeData() { return 0; }
+
+    // Return the headers (an array of strings, one per line,
+    // NULL-terminated) for the main menu.  Typically these tell users
+    // what to push to move the selection and invoke the selected
+    // item.
+    virtual const char* const* GetMenuHeaders() = 0;
+
+    // Return the list of menu items (an array of strings,
+    // NULL-terminated).  The menu_position passed to InvokeMenuItem
+    // will correspond to the indexes into this array.
+    virtual const char* const* GetMenuItems() = 0;
+};
+
+// The device-specific library must define this function (or the
+// default one will be used, if there is no device-specific library).
+// It returns the Device object that recovery should use.
+Device* make_device();
+
+#endif  // _DEVICE_H
diff --git a/install.c b/install.cpp
similarity index 77%
rename from install.c
rename to install.cpp
index 9d7595e..0783433 100644
--- a/install.c
+++ b/install.cpp
@@ -32,10 +32,19 @@
 #include "mtdutils/mtdutils.h"
 #include "roots.h"
 #include "verifier.h"
+#include "ui.h"
+
+extern RecoveryUI* ui;
 
 #define ASSUMED_UPDATE_BINARY_NAME  "META-INF/com/google/android/update-binary"
 #define PUBLIC_KEYS_FILE "/res/keys"
 
+// Default allocation of progress bar segments to operations
+static const int VERIFICATION_PROGRESS_TIME = 60;
+static const float VERIFICATION_PROGRESS_FRACTION = 0.25;
+static const float DEFAULT_FILES_PROGRESS_FRACTION = 0.4;
+static const float DEFAULT_IMAGE_PROGRESS_FRACTION = 0.1;
+
 // If the package contains an update binary, extract it and run it.
 static int
 try_update_binary(const char *path, ZipArchive *zip, int* wipe_cache) {
@@ -46,7 +55,7 @@
         return INSTALL_CORRUPT;
     }
 
-    char* binary = "/tmp/update_binary";
+    const char* binary = "/tmp/update_binary";
     unlink(binary);
     int fd = creat(binary, 0755);
     if (fd < 0) {
@@ -100,18 +109,19 @@
     //   - the name of the package zip file.
     //
 
-    char** args = malloc(sizeof(char*) * 5);
+    const char** args = (const char**)malloc(sizeof(char*) * 5);
     args[0] = binary;
     args[1] = EXPAND(RECOVERY_API_VERSION);   // defined in Android.mk
-    args[2] = malloc(10);
-    sprintf(args[2], "%d", pipefd[1]);
+    char* temp = (char*)malloc(10);
+    sprintf(temp, "%d", pipefd[1]);
+    args[2] = temp;
     args[3] = (char*)path;
     args[4] = NULL;
 
     pid_t pid = fork();
     if (pid == 0) {
         close(pipefd[0]);
-        execv(binary, args);
+        execv(binary, (char* const*)args);
         fprintf(stdout, "E:Can't run %s (%s)\n", binary, strerror(errno));
         _exit(-1);
     }
@@ -132,18 +142,17 @@
             float fraction = strtof(fraction_s, NULL);
             int seconds = strtol(seconds_s, NULL, 10);
 
-            ui_show_progress(fraction * (1-VERIFICATION_PROGRESS_FRACTION),
-                             seconds);
+            ui->ShowProgress(fraction * (1-VERIFICATION_PROGRESS_FRACTION), seconds);
         } else if (strcmp(command, "set_progress") == 0) {
             char* fraction_s = strtok(NULL, " \n");
             float fraction = strtof(fraction_s, NULL);
-            ui_set_progress(fraction);
+            ui->SetProgress(fraction);
         } else if (strcmp(command, "ui_print") == 0) {
             char* str = strtok(NULL, "\n");
             if (str) {
-                ui_print("%s", str);
+                ui->Print("%s", str);
             } else {
-                ui_print("\n");
+                ui->Print("\n");
             }
         } else if (strcmp(command, "wipe_cache") == 0) {
             *wipe_cache = 1;
@@ -188,31 +197,32 @@
         goto exit;
     }
 
-    int i;
-    bool done = false;
-    while (!done) {
-        ++*numKeys;
-        out = realloc(out, *numKeys * sizeof(RSAPublicKey));
-        RSAPublicKey* key = out + (*numKeys - 1);
-        if (fscanf(f, " { %i , 0x%x , { %u",
-                   &(key->len), &(key->n0inv), &(key->n[0])) != 3) {
-            goto exit;
-        }
-        if (key->len != RSANUMWORDS) {
-            LOGE("key length (%d) does not match expected size\n", key->len);
-            goto exit;
-        }
-        for (i = 1; i < key->len; ++i) {
-            if (fscanf(f, " , %u", &(key->n[i])) != 1) goto exit;
-        }
-        if (fscanf(f, " } , { %u", &(key->rr[0])) != 1) goto exit;
-        for (i = 1; i < key->len; ++i) {
-            if (fscanf(f, " , %u", &(key->rr[i])) != 1) goto exit;
-        }
-        fscanf(f, " } } ");
+    {
+        int i;
+        bool done = false;
+        while (!done) {
+            ++*numKeys;
+            out = (RSAPublicKey*)realloc(out, *numKeys * sizeof(RSAPublicKey));
+            RSAPublicKey* key = out + (*numKeys - 1);
+            if (fscanf(f, " { %i , 0x%x , { %u",
+                       &(key->len), &(key->n0inv), &(key->n[0])) != 3) {
+                goto exit;
+            }
+            if (key->len != RSANUMWORDS) {
+                LOGE("key length (%d) does not match expected size\n", key->len);
+                goto exit;
+            }
+            for (i = 1; i < key->len; ++i) {
+                if (fscanf(f, " , %u", &(key->n[i])) != 1) goto exit;
+            }
+            if (fscanf(f, " } , { %u", &(key->rr[0])) != 1) goto exit;
+            for (i = 1; i < key->len; ++i) {
+                if (fscanf(f, " , %u", &(key->rr[i])) != 1) goto exit;
+            }
+            fscanf(f, " } } ");
 
-        // if the line ends in a comma, this file has more keys.
-        switch (fgetc(f)) {
+            // if the line ends in a comma, this file has more keys.
+            switch (fgetc(f)) {
             case ',':
                 // more keys to come.
                 break;
@@ -224,6 +234,7 @@
             default:
                 LOGE("unexpected character between keys\n");
                 goto exit;
+            }
         }
     }
 
@@ -240,9 +251,9 @@
 static int
 really_install_package(const char *path, int* wipe_cache)
 {
-    ui_set_background(BACKGROUND_ICON_INSTALLING);
-    ui_print("Finding update package...\n");
-    ui_show_indeterminate_progress();
+    ui->SetBackground(RecoveryUI::INSTALLING);
+    ui->Print("Finding update package...\n");
+    ui->SetProgressType(RecoveryUI::INDETERMINATE);
     LOGI("Update location: %s\n", path);
 
     if (ensure_path_mounted(path) != 0) {
@@ -250,7 +261,7 @@
         return INSTALL_CORRUPT;
     }
 
-    ui_print("Opening update package...\n");
+    ui->Print("Opening update package...\n");
 
     int numKeys;
     RSAPublicKey* loadedKeys = load_keys(PUBLIC_KEYS_FILE, &numKeys);
@@ -261,10 +272,9 @@
     LOGI("%d key(s) loaded from %s\n", numKeys, PUBLIC_KEYS_FILE);
 
     // Give verification half the progress bar...
-    ui_print("Verifying update package...\n");
-    ui_show_progress(
-            VERIFICATION_PROGRESS_FRACTION,
-            VERIFICATION_PROGRESS_TIME);
+    ui->Print("Verifying update package...\n");
+    ui->SetProgressType(RecoveryUI::DETERMINATE);
+    ui->ShowProgress(VERIFICATION_PROGRESS_FRACTION, VERIFICATION_PROGRESS_TIME);
 
     int err;
     err = verify_file(path, loadedKeys, numKeys);
@@ -286,7 +296,7 @@
 
     /* Verify and install the contents of the package.
      */
-    ui_print("Installing update...\n");
+    ui->Print("Installing update...\n");
     return try_update_binary(path, &zip, wipe_cache);
 }
 
diff --git a/install.h b/install.h
index 5ebe160..1943f02 100644
--- a/install.h
+++ b/install.h
@@ -19,6 +19,10 @@
 
 #include "common.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 enum { INSTALL_SUCCESS, INSTALL_ERROR, INSTALL_CORRUPT };
 // Install the package specified by root_path.  If INSTALL_SUCCESS is
 // returned and *wipe_cache is true on exit, caller should wipe the
@@ -26,4 +30,8 @@
 int install_package(const char *root_path, int* wipe_cache,
                     const char* install_file);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif  // RECOVERY_INSTALL_H_
diff --git a/minui/minui.h b/minui/minui.h
index 2e2f1f4..74da4e9 100644
--- a/minui/minui.h
+++ b/minui/minui.h
@@ -19,6 +19,10 @@
 
 #include <stdbool.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef void* gr_surface;
 typedef unsigned short gr_pixel;
 
@@ -69,4 +73,8 @@
 int res_create_surface(const char* name, gr_surface* pSurface);
 void res_free_surface(gr_surface surface);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif
diff --git a/minzip/DirUtil.h b/minzip/DirUtil.h
index 5d881f5..0d5ea7c 100644
--- a/minzip/DirUtil.h
+++ b/minzip/DirUtil.h
@@ -20,6 +20,10 @@
 #include <stdbool.h>
 #include <utime.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Like "mkdir -p", try to guarantee that all directories
  * specified in path are present, creating as many directories
  * as necessary.  The specified mode is passed to all mkdir
@@ -48,4 +52,8 @@
 int dirSetHierarchyPermissions(const char *path,
          int uid, int gid, int dirMode, int fileMode);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif  // MINZIP_DIRUTIL_H_
diff --git a/minzip/Zip.h b/minzip/Zip.h
index 9f99fba..739dbf5 100644
--- a/minzip/Zip.h
+++ b/minzip/Zip.h
@@ -14,6 +14,10 @@
 #include "Hash.h"
 #include "SysUtil.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /*
  * One entry in the Zip archive.  Treat this as opaque -- use accessors below.
  *
@@ -210,4 +214,8 @@
         int flags, const struct utimbuf *timestamp,
         void (*callback)(const char *fn, void*), void *cookie);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /*_MINZIP_ZIP*/
diff --git a/mtdutils/mounts.h b/mtdutils/mounts.h
index 30b2927..d721355 100644
--- a/mtdutils/mounts.h
+++ b/mtdutils/mounts.h
@@ -17,6 +17,10 @@
 #ifndef MTDUTILS_MOUNTS_H_
 #define MTDUTILS_MOUNTS_H_
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct MountedVolume MountedVolume;
 
 int scan_mounted_volumes(void);
@@ -30,4 +34,8 @@
 
 int remount_read_only(const MountedVolume* volume);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif  // MTDUTILS_MOUNTS_H_
diff --git a/mtdutils/mtdutils.h b/mtdutils/mtdutils.h
index 45d3ebc..2708c43 100644
--- a/mtdutils/mtdutils.h
+++ b/mtdutils/mtdutils.h
@@ -19,6 +19,10 @@
 
 #include <sys/types.h>  // for size_t, etc.
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct MtdPartition MtdPartition;
 
 int mtd_scan_partitions(void);
@@ -53,4 +57,8 @@
 off_t mtd_find_write_start(MtdWriteContext *ctx, off_t pos);
 int mtd_write_close(MtdWriteContext *);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif  // MTDUTILS_H_
diff --git a/recovery.c b/recovery.cpp
similarity index 81%
rename from recovery.c
rename to recovery.cpp
index 06d6498..a0d96d2 100644
--- a/recovery.c
+++ b/recovery.cpp
@@ -37,7 +37,9 @@
 #include "minui/minui.h"
 #include "minzip/DirUtil.h"
 #include "roots.h"
-#include "recovery_ui.h"
+#include "ui.h"
+#include "screen_ui.h"
+#include "device.h"
 
 static const struct option OPTIONS[] = {
   { "send_intent", required_argument, NULL, 's' },
@@ -59,7 +61,7 @@
 static const char *TEMPORARY_INSTALL_FILE = "/tmp/last_install";
 static const char *SIDELOAD_TEMP_DIR = "/tmp/sideload";
 
-extern UIParameters ui_parameters;    // from ui.c
+RecoveryUI* ui = NULL;
 
 /*
  * The recovery tool communicates with the main system through /cache files.
@@ -290,9 +292,9 @@
 
 static int
 erase_volume(const char *volume) {
-    ui_set_background(BACKGROUND_ICON_INSTALLING);
-    ui_show_indeterminate_progress();
-    ui_print("Formatting %s...\n", volume);
+    ui->SetBackground(RecoveryUI::INSTALLING);
+    ui->SetProgressType(RecoveryUI::INDETERMINATE);
+    ui->Print("Formatting %s...\n", volume);
 
     ensure_path_unmounted(volume);
 
@@ -349,7 +351,7 @@
   strcpy(copy_path, SIDELOAD_TEMP_DIR);
   strcat(copy_path, "/package.zip");
 
-  char* buffer = malloc(BUFSIZ);
+  char* buffer = (char*)malloc(BUFSIZ);
   if (buffer == NULL) {
     LOGE("Failed to allocate buffer\n");
     return NULL;
@@ -396,22 +398,22 @@
   return strdup(copy_path);
 }
 
-static char**
-prepend_title(const char** headers) {
-    char* title[] = { "Android system recovery <"
-                          EXPAND(RECOVERY_API_VERSION) "e>",
-                      "",
-                      NULL };
+static const char**
+prepend_title(const char* const* headers) {
+    const char* title[] = { "Android system recovery <"
+                            EXPAND(RECOVERY_API_VERSION) "e>",
+                            "",
+                            NULL };
 
     // count the number of lines in our title, plus the
     // caller-provided headers.
     int count = 0;
-    char** p;
+    const char* const* p;
     for (p = title; *p; ++p, ++count);
     for (p = headers; *p; ++p, ++count);
 
-    char** new_headers = malloc((count+1) * sizeof(char*));
-    char** h = new_headers;
+    const char** new_headers = (const char**)malloc((count+1) * sizeof(char*));
+    const char** h = new_headers;
     for (p = title; *p; ++p, ++h) *h = *p;
     for (p = headers; *p; ++p, ++h) *h = *p;
     *h = NULL;
@@ -420,46 +422,46 @@
 }
 
 static int
-get_menu_selection(char** headers, char** items, int menu_only,
-                   int initial_selection) {
+get_menu_selection(const char* const * headers, const char* const * items,
+                   int menu_only, int initial_selection, Device* device) {
     // throw away keys pressed previously, so user doesn't
     // accidentally trigger menu items.
-    ui_clear_key_queue();
+    ui->FlushKeys();
 
-    ui_start_menu(headers, items, initial_selection);
+    ui->StartMenu(headers, items, initial_selection);
     int selected = initial_selection;
     int chosen_item = -1;
 
     while (chosen_item < 0) {
-        int key = ui_wait_key();
-        int visible = ui_text_visible();
+        int key = ui->WaitKey();
+        int visible = ui->IsTextVisible();
 
         if (key == -1) {   // ui_wait_key() timed out
-            if (ui_text_ever_visible()) {
+            if (ui->WasTextEverVisible()) {
                 continue;
             } else {
                 LOGI("timed out waiting for key input; rebooting.\n");
-                ui_end_menu();
-                return ITEM_REBOOT;
+                ui->EndMenu();
+                return 0; // XXX fixme
             }
         }
 
-        int action = device_handle_key(key, visible);
+        int action = device->HandleMenuKey(key, visible);
 
         if (action < 0) {
             switch (action) {
-                case HIGHLIGHT_UP:
+                case Device::kHighlightUp:
                     --selected;
-                    selected = ui_menu_select(selected);
+                    selected = ui->SelectMenu(selected);
                     break;
-                case HIGHLIGHT_DOWN:
+                case Device::kHighlightDown:
                     ++selected;
-                    selected = ui_menu_select(selected);
+                    selected = ui->SelectMenu(selected);
                     break;
-                case SELECT_ITEM:
+                case Device::kInvokeItem:
                     chosen_item = selected;
                     break;
-                case NO_ACTION:
+                case Device::kNoAction:
                     break;
             }
         } else if (!menu_only) {
@@ -467,7 +469,7 @@
         }
     }
 
-    ui_end_menu();
+    ui->EndMenu();
     return chosen_item;
 }
 
@@ -477,7 +479,7 @@
 
 static int
 update_directory(const char* path, const char* unmount_when_done,
-                 int* wipe_cache) {
+                 int* wipe_cache, Device* device) {
     ensure_path_mounted(path);
 
     const char* MENU_HEADERS[] = { "Choose a package to install:",
@@ -495,14 +497,14 @@
         return 0;
     }
 
-    char** headers = prepend_title(MENU_HEADERS);
+    const char** headers = prepend_title(MENU_HEADERS);
 
     int d_size = 0;
     int d_alloc = 10;
-    char** dirs = malloc(d_alloc * sizeof(char*));
+    char** dirs = (char**)malloc(d_alloc * sizeof(char*));
     int z_size = 1;
     int z_alloc = 10;
-    char** zips = malloc(z_alloc * sizeof(char*));
+    char** zips = (char**)malloc(z_alloc * sizeof(char*));
     zips[0] = strdup("../");
 
     while ((de = readdir(d)) != NULL) {
@@ -516,9 +518,9 @@
 
             if (d_size >= d_alloc) {
                 d_alloc *= 2;
-                dirs = realloc(dirs, d_alloc * sizeof(char*));
+                dirs = (char**)realloc(dirs, d_alloc * sizeof(char*));
             }
-            dirs[d_size] = malloc(name_len + 2);
+            dirs[d_size] = (char*)malloc(name_len + 2);
             strcpy(dirs[d_size], de->d_name);
             dirs[d_size][name_len] = '/';
             dirs[d_size][name_len+1] = '\0';
@@ -528,7 +530,7 @@
                    strncasecmp(de->d_name + (name_len-4), ".zip", 4) == 0) {
             if (z_size >= z_alloc) {
                 z_alloc *= 2;
-                zips = realloc(zips, z_alloc * sizeof(char*));
+                zips = (char**)realloc(zips, z_alloc * sizeof(char*));
             }
             zips[z_size++] = strdup(de->d_name);
         }
@@ -541,7 +543,7 @@
     // append dirs to the zips list
     if (d_size + z_size + 1 > z_alloc) {
         z_alloc = d_size + z_size + 1;
-        zips = realloc(zips, z_alloc * sizeof(char*));
+        zips = (char**)realloc(zips, z_alloc * sizeof(char*));
     }
     memcpy(zips + z_size, dirs, d_size * sizeof(char*));
     free(dirs);
@@ -551,7 +553,7 @@
     int result;
     int chosen_item = 0;
     do {
-        chosen_item = get_menu_selection(headers, zips, 1, chosen_item);
+        chosen_item = get_menu_selection(headers, zips, 1, chosen_item, device);
 
         char* item = zips[chosen_item];
         int item_len = strlen(item);
@@ -566,7 +568,7 @@
             strlcat(new_path, "/", PATH_MAX);
             strlcat(new_path, item, PATH_MAX);
             new_path[strlen(new_path)-1] = '\0';  // truncate the trailing '/'
-            result = update_directory(new_path, unmount_when_done, wipe_cache);
+            result = update_directory(new_path, unmount_when_done, wipe_cache, device);
             if (result >= 0) break;
         } else {
             // selected a zip file:  attempt to install it, and return
@@ -576,7 +578,7 @@
             strlcat(new_path, "/", PATH_MAX);
             strlcat(new_path, item, PATH_MAX);
 
-            ui_print("\n-- Install %s ...\n", path);
+            ui->Print("\n-- Install %s ...\n", path);
             set_sdcard_update_bootloader_message();
             char* copy = copy_sideloaded_package(new_path);
             if (unmount_when_done != NULL) {
@@ -604,121 +606,121 @@
 }
 
 static void
-wipe_data(int confirm) {
+wipe_data(int confirm, Device* device) {
     if (confirm) {
-        static char** title_headers = NULL;
+        static const char** title_headers = NULL;
 
         if (title_headers == NULL) {
-            char* headers[] = { "Confirm wipe of all user data?",
-                                "  THIS CAN NOT BE UNDONE.",
-                                "",
-                                NULL };
+            const char* headers[] = { "Confirm wipe of all user data?",
+                                      "  THIS CAN NOT BE UNDONE.",
+                                      "",
+                                      NULL };
             title_headers = prepend_title((const char**)headers);
         }
 
-        char* items[] = { " No",
-                          " No",
-                          " No",
-                          " No",
-                          " No",
-                          " No",
-                          " No",
-                          " Yes -- delete all user data",   // [7]
-                          " No",
-                          " No",
-                          " No",
-                          NULL };
+        const char* items[] = { " No",
+                                " No",
+                                " No",
+                                " No",
+                                " No",
+                                " No",
+                                " No",
+                                " Yes -- delete all user data",   // [7]
+                                " No",
+                                " No",
+                                " No",
+                                NULL };
 
-        int chosen_item = get_menu_selection(title_headers, items, 1, 0);
+        int chosen_item = get_menu_selection(title_headers, items, 1, 0, device);
         if (chosen_item != 7) {
             return;
         }
     }
 
-    ui_print("\n-- Wiping data...\n");
-    device_wipe_data();
+    ui->Print("\n-- Wiping data...\n");
+    device->WipeData();
     erase_volume("/data");
     erase_volume("/cache");
-    ui_print("Data wipe complete.\n");
+    ui->Print("Data wipe complete.\n");
 }
 
 static void
-prompt_and_wait() {
-    char** headers = prepend_title((const char**)MENU_HEADERS);
+prompt_and_wait(Device* device) {
+    const char* const* headers = prepend_title(device->GetMenuHeaders());
 
     for (;;) {
         finish_recovery(NULL);
-        ui_reset_progress();
+        ui->SetProgressType(RecoveryUI::EMPTY);
 
-        int chosen_item = get_menu_selection(headers, MENU_ITEMS, 0, 0);
+        int chosen_item = get_menu_selection(headers, device->GetMenuItems(), 0, 0, device);
 
         // device-specific code may take some action here.  It may
         // return one of the core actions handled in the switch
         // statement below.
-        chosen_item = device_perform_action(chosen_item);
+        chosen_item = device->InvokeMenuItem(chosen_item);
 
         int status;
         int wipe_cache;
         switch (chosen_item) {
-            case ITEM_REBOOT:
+            case Device::REBOOT:
                 return;
 
-            case ITEM_WIPE_DATA:
-                wipe_data(ui_text_visible());
-                if (!ui_text_visible()) return;
+            case Device::WIPE_DATA:
+                wipe_data(ui->IsTextVisible(), device);
+                if (!ui->IsTextVisible()) return;
                 break;
 
-            case ITEM_WIPE_CACHE:
-                ui_print("\n-- Wiping cache...\n");
+            case Device::WIPE_CACHE:
+                ui->Print("\n-- Wiping cache...\n");
                 erase_volume("/cache");
-                ui_print("Cache wipe complete.\n");
-                if (!ui_text_visible()) return;
+                ui->Print("Cache wipe complete.\n");
+                if (!ui->IsTextVisible()) return;
                 break;
 
-            case ITEM_APPLY_SDCARD:
-                status = update_directory(SDCARD_ROOT, SDCARD_ROOT, &wipe_cache);
+            case Device::APPLY_EXT:
+                status = update_directory(SDCARD_ROOT, SDCARD_ROOT, &wipe_cache, device);
                 if (status == INSTALL_SUCCESS && wipe_cache) {
-                    ui_print("\n-- Wiping cache (at package request)...\n");
+                    ui->Print("\n-- Wiping cache (at package request)...\n");
                     if (erase_volume("/cache")) {
-                        ui_print("Cache wipe failed.\n");
+                        ui->Print("Cache wipe failed.\n");
                     } else {
-                        ui_print("Cache wipe complete.\n");
+                        ui->Print("Cache wipe complete.\n");
                     }
                 }
                 if (status >= 0) {
                     if (status != INSTALL_SUCCESS) {
-                        ui_set_background(BACKGROUND_ICON_ERROR);
-                        ui_print("Installation aborted.\n");
-                    } else if (!ui_text_visible()) {
+                        ui->SetBackground(RecoveryUI::ERROR);
+                        ui->Print("Installation aborted.\n");
+                    } else if (!ui->IsTextVisible()) {
                         return;  // reboot if logs aren't visible
                     } else {
-                        ui_print("\nInstall from sdcard complete.\n");
+                        ui->Print("\nInstall from sdcard complete.\n");
                     }
                 }
                 break;
-            case ITEM_APPLY_CACHE:
+
+            case Device::APPLY_CACHE:
                 // Don't unmount cache at the end of this.
-                status = update_directory(CACHE_ROOT, NULL, &wipe_cache);
+                status = update_directory(CACHE_ROOT, NULL, &wipe_cache, device);
                 if (status == INSTALL_SUCCESS && wipe_cache) {
-                    ui_print("\n-- Wiping cache (at package request)...\n");
+                    ui->Print("\n-- Wiping cache (at package request)...\n");
                     if (erase_volume("/cache")) {
-                        ui_print("Cache wipe failed.\n");
+                        ui->Print("Cache wipe failed.\n");
                     } else {
-                        ui_print("Cache wipe complete.\n");
+                        ui->Print("Cache wipe complete.\n");
                     }
                 }
                 if (status >= 0) {
                     if (status != INSTALL_SUCCESS) {
-                        ui_set_background(BACKGROUND_ICON_ERROR);
-                        ui_print("Installation aborted.\n");
-                    } else if (!ui_text_visible()) {
+                        ui->SetBackground(RecoveryUI::ERROR);
+                        ui->Print("Installation aborted.\n");
+                    } else if (!ui->IsTextVisible()) {
                         return;  // reboot if logs aren't visible
                     } else {
-                        ui_print("\nInstall from cache complete.\n");
+                        ui->Print("\nInstall from cache complete.\n");
                     }
                 }
                 break;
-
         }
     }
 }
@@ -737,9 +739,11 @@
     freopen(TEMPORARY_LOG_FILE, "a", stderr); setbuf(stderr, NULL);
     printf("Starting recovery on %s", ctime(&start));
 
-    device_ui_init(&ui_parameters);
-    ui_init();
-    ui_set_background(BACKGROUND_ICON_INSTALLING);
+    Device* device = make_device();
+    ui = device->GetUI();
+
+    ui->Init();
+    ui->SetBackground(RecoveryUI::NONE);
     load_volume_table();
     get_args(&argc, &argv);
 
@@ -756,14 +760,14 @@
         case 'u': update_package = optarg; break;
         case 'w': wipe_data = wipe_cache = 1; break;
         case 'c': wipe_cache = 1; break;
-        case 't': ui_show_text(1); break;
+        case 't': ui->ShowText(true); break;
         case '?':
             LOGE("Invalid command argument\n");
             continue;
         }
     }
 
-    device_recovery_start();
+    device->StartRecovery();
 
     printf("Command:");
     for (arg = 0; arg < argc; arg++) {
@@ -777,7 +781,7 @@
         // "/cache/foo".
         if (strncmp(update_package, "CACHE:", 6) == 0) {
             int len = strlen(update_package) + 10;
-            char* modified_path = malloc(len);
+            char* modified_path = (char*)malloc(len);
             strlcpy(modified_path, "/cache/", len);
             strlcat(modified_path, update_package+6, len);
             printf("(replacing path \"%s\" with \"%s\")\n",
@@ -799,27 +803,27 @@
                 LOGE("Cache wipe (requested by package) failed.");
             }
         }
-        if (status != INSTALL_SUCCESS) ui_print("Installation aborted.\n");
+        if (status != INSTALL_SUCCESS) ui->Print("Installation aborted.\n");
     } else if (wipe_data) {
-        if (device_wipe_data()) status = INSTALL_ERROR;
+        if (device->WipeData()) status = INSTALL_ERROR;
         if (erase_volume("/data")) status = INSTALL_ERROR;
         if (wipe_cache && erase_volume("/cache")) status = INSTALL_ERROR;
-        if (status != INSTALL_SUCCESS) ui_print("Data wipe failed.\n");
+        if (status != INSTALL_SUCCESS) ui->Print("Data wipe failed.\n");
     } else if (wipe_cache) {
         if (wipe_cache && erase_volume("/cache")) status = INSTALL_ERROR;
-        if (status != INSTALL_SUCCESS) ui_print("Cache wipe failed.\n");
+        if (status != INSTALL_SUCCESS) ui->Print("Cache wipe failed.\n");
     } else {
         status = INSTALL_ERROR;  // No command specified
     }
 
-    if (status != INSTALL_SUCCESS) ui_set_background(BACKGROUND_ICON_ERROR);
-    if (status != INSTALL_SUCCESS || ui_text_visible()) {
-        prompt_and_wait();
+    if (status != INSTALL_SUCCESS) ui->SetBackground(RecoveryUI::ERROR);
+    if (status != INSTALL_SUCCESS || ui->IsTextVisible()) {
+        prompt_and_wait(device);
     }
 
     // Otherwise, get ready to boot the main system...
     finish_recovery(send_intent);
-    ui_print("Rebooting...\n");
+    ui->Print("Rebooting...\n");
     android_reboot(ANDROID_RB_RESTART, 0, 0);
     return EXIT_SUCCESS;
 }
diff --git a/recovery_ui.h b/recovery_ui.h
deleted file mode 100644
index 5f01770..0000000
--- a/recovery_ui.h
+++ /dev/null
@@ -1,87 +0,0 @@
-/*
- * Copyright (C) 2009 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.
- */
-
-#ifndef _RECOVERY_UI_H
-#define _RECOVERY_UI_H
-
-#include "common.h"
-
-// Called before UI library is initialized.  Can change things like
-// how many frames are included in various animations, etc.
-extern void device_ui_init(UIParameters* ui_parameters);
-
-// Called when recovery starts up.  Returns 0.
-extern int device_recovery_start();
-
-// Called in the input thread when a new key (key_code) is pressed.
-// *key_pressed is an array of KEY_MAX+1 bytes indicating which other
-// keys are already pressed.  Return true if the text display should
-// be toggled.
-extern int device_toggle_display(volatile char* key_pressed, int key_code);
-
-// Called in the input thread when a new key (key_code) is pressed.
-// *key_pressed is an array of KEY_MAX+1 bytes indicating which other
-// keys are already pressed.  Return true if the device should reboot
-// immediately.
-extern int device_reboot_now(volatile char* key_pressed, int key_code);
-
-// Called from the main thread when recovery is waiting for input and
-// a key is pressed.  key is the code of the key pressed; visible is
-// true if the recovery menu is being shown.  Implementations can call
-// ui_key_pressed() to discover if other keys are being held down.
-// Return one of the defined constants below in order to:
-//
-//   - move the menu highlight (HIGHLIGHT_*)
-//   - invoke the highlighted item (SELECT_ITEM)
-//   - do nothing (NO_ACTION)
-//   - invoke a specific action (a menu position: any non-negative number)
-extern int device_handle_key(int key, int visible);
-
-// Perform a recovery action selected from the menu.  'which' will be
-// the item number of the selected menu item, or a non-negative number
-// returned from device_handle_key().  The menu will be hidden when
-// this is called; implementations can call ui_print() to print
-// information to the screen.
-extern int device_perform_action(int which);
-
-// Called when we do a wipe data/factory reset operation (either via a
-// reboot from the main system with the --wipe_data flag, or when the
-// user boots into recovery manually and selects the option from the
-// menu.)  Can perform whatever device-specific wiping actions are
-// needed.  Return 0 on success.  The userdata and cache partitions
-// are erased after this returns (whether it returns success or not).
-int device_wipe_data();
-
-#define NO_ACTION           -1
-
-#define HIGHLIGHT_UP        -2
-#define HIGHLIGHT_DOWN      -3
-#define SELECT_ITEM         -4
-
-#define ITEM_REBOOT          0
-#define ITEM_APPLY_EXT       1
-#define ITEM_APPLY_SDCARD    1  // historical synonym for ITEM_APPLY_EXT
-#define ITEM_WIPE_DATA       2
-#define ITEM_WIPE_CACHE      3
-#define ITEM_APPLY_CACHE     4
-
-// Header text to display above the main menu.
-extern char* MENU_HEADERS[];
-
-// Text of menu items.
-extern char* MENU_ITEMS[];
-
-#endif
diff --git a/roots.c b/roots.cpp
similarity index 97%
rename from roots.c
rename to roots.cpp
index cb7e067..9345cb0 100644
--- a/roots.c
+++ b/roots.cpp
@@ -33,7 +33,7 @@
 
 static int parse_options(char* options, Volume* volume) {
     char* option;
-    while (option = strtok(options, ",")) {
+    while ((option = strtok(options, ","))) {
         options = NULL;
 
         if (strncmp(option, "length=", 7) == 0) {
@@ -48,7 +48,7 @@
 
 void load_volume_table() {
     int alloc = 2;
-    device_volumes = malloc(alloc * sizeof(Volume));
+    device_volumes = (Volume*)malloc(alloc * sizeof(Volume));
 
     // Insert an entry for /tmp, which is the ramdisk and is always mounted.
     device_volumes[0].mount_point = "/tmp";
@@ -91,7 +91,7 @@
         if (mount_point && fs_type && device) {
             while (num_volumes >= alloc) {
                 alloc *= 2;
-                device_volumes = realloc(device_volumes, alloc*sizeof(Volume));
+                device_volumes = (Volume*)realloc(device_volumes, alloc*sizeof(Volume));
             }
             device_volumes[num_volumes].mount_point = strdup(mount_point);
             device_volumes[num_volumes].fs_type = strdup(fs_type);
diff --git a/roots.h b/roots.h
index cf59bfd..8abe18f 100644
--- a/roots.h
+++ b/roots.h
@@ -19,6 +19,10 @@
 
 #include "common.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 // Load and parse volume data from /etc/recovery.fstab.
 void load_volume_table();
 
@@ -38,4 +42,8 @@
 // it is mounted.
 int format_volume(const char* volume);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif  // RECOVERY_ROOTS_H_
diff --git a/screen_ui.cpp b/screen_ui.cpp
new file mode 100644
index 0000000..2a8652e
--- /dev/null
+++ b/screen_ui.cpp
@@ -0,0 +1,488 @@
+/*
+ * 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 "common.h"
+#include "device.h"
+#include "minui/minui.h"
+#include "screen_ui.h"
+#include "ui.h"
+
+#define CHAR_WIDTH 10
+#define CHAR_HEIGHT 18
+
+// 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 ScreenRecoveryUI* self = NULL;
+
+// Return the current time as a double (including fractions of a second).
+static double now() {
+    struct timeval tv;
+    gettimeofday(&tv, NULL);
+    return tv.tv_sec + tv.tv_usec / 1000000.0;
+}
+
+ScreenRecoveryUI::ScreenRecoveryUI() :
+    currentIcon(NONE),
+    installingFrame(0),
+    progressBarType(EMPTY),
+    progressScopeStart(0),
+    progressScopeSize(0),
+    progress(0),
+    pagesIdentical(false),
+    text_cols(0),
+    text_rows(0),
+    text_col(0),
+    text_row(0),
+    text_top(0),
+    show_text(false),
+    show_text_ever(false),
+    show_menu(false),
+    menu_top(0),
+    menu_items(0),
+    menu_sel(0),
+
+    // These values are correct for the default image resources
+    // provided with the android platform.  Devices which use
+    // different resources should have a subclass of ScreenRecoveryUI
+    // that overrides Init() to set these values appropriately and
+    // then call the superclass Init().
+    animation_fps(20),
+    indeterminate_frames(6),
+    installing_frames(7),
+    install_overlay_offset_x(13),
+    install_overlay_offset_y(190) {
+    pthread_mutex_init(&updateMutex, NULL);
+    self = this;
+}
+
+// Draw the given frame over the installation overlay animation.  The
+// background is not cleared or draw with the base icon first; we
+// assume that the frame already contains some other frame of the
+// animation.  Does nothing if no overlay animation is defined.
+// Should only be called with updateMutex locked.
+void ScreenRecoveryUI::draw_install_overlay_locked(int frame) {
+    if (installationOverlay == NULL) return;
+    gr_surface surface = installationOverlay[frame];
+    int iconWidth = gr_get_width(surface);
+    int iconHeight = gr_get_height(surface);
+    gr_blit(surface, 0, 0, iconWidth, iconHeight,
+            install_overlay_offset_x, install_overlay_offset_y);
+}
+
+// Clear the screen and draw the currently selected background icon (if any).
+// Should only be called with updateMutex locked.
+void ScreenRecoveryUI::draw_background_locked(Icon icon)
+{
+    pagesIdentical = false;
+    gr_color(0, 0, 0, 255);
+    gr_fill(0, 0, gr_fb_width(), gr_fb_height());
+
+    if (icon) {
+        gr_surface surface = backgroundIcon[icon];
+        int iconWidth = gr_get_width(surface);
+        int iconHeight = gr_get_height(surface);
+        int iconX = (gr_fb_width() - iconWidth) / 2;
+        int iconY = (gr_fb_height() - iconHeight) / 2;
+        gr_blit(surface, 0, 0, iconWidth, iconHeight, iconX, iconY);
+        if (icon == INSTALLING) {
+            draw_install_overlay_locked(installingFrame);
+        }
+    }
+}
+
+// Draw the progress bar (if any) on the screen.  Does not flip pages.
+// Should only be called with updateMutex locked.
+void ScreenRecoveryUI::draw_progress_locked()
+{
+    if (currentIcon == INSTALLING) {
+        draw_install_overlay_locked(installingFrame);
+    }
+
+    if (progressBarType != EMPTY) {
+        int iconHeight = gr_get_height(backgroundIcon[INSTALLING]);
+        int width = gr_get_width(progressBarEmpty);
+        int height = gr_get_height(progressBarEmpty);
+
+        int dx = (gr_fb_width() - width)/2;
+        int dy = (3*gr_fb_height() + iconHeight - 2*height)/4;
+
+        // Erase behind the progress bar (in case this was a progress-only update)
+        gr_color(0, 0, 0, 255);
+        gr_fill(dx, dy, width, height);
+
+        if (progressBarType == DETERMINATE) {
+            float p = progressScopeStart + progress * progressScopeSize;
+            int pos = (int) (p * width);
+
+            if (pos > 0) {
+                gr_blit(progressBarFill, 0, 0, pos, height, dx, dy);
+            }
+            if (pos < width-1) {
+                gr_blit(progressBarEmpty, pos, 0, width-pos, height, dx+pos, dy);
+            }
+        }
+
+        if (progressBarType == INDETERMINATE) {
+            static int frame = 0;
+            gr_blit(progressBarIndeterminate[frame], 0, 0, width, height, dx, dy);
+            frame = (frame + 1) % indeterminate_frames;
+        }
+    }
+}
+
+void ScreenRecoveryUI::draw_text_line(int row, const char* t) {
+  if (t[0] != '\0') {
+    gr_text(0, (row+1)*CHAR_HEIGHT-1, t);
+  }
+}
+
+// Redraw everything on the screen.  Does not flip pages.
+// Should only be called with updateMutex locked.
+void ScreenRecoveryUI::draw_screen_locked()
+{
+    draw_background_locked(currentIcon);
+    draw_progress_locked();
+
+    if (show_text) {
+        gr_color(0, 0, 0, 160);
+        gr_fill(0, 0, gr_fb_width(), gr_fb_height());
+
+        int i = 0;
+        if (show_menu) {
+            gr_color(64, 96, 255, 255);
+            gr_fill(0, (menu_top+menu_sel) * CHAR_HEIGHT,
+                    gr_fb_width(), (menu_top+menu_sel+1)*CHAR_HEIGHT+1);
+
+            for (; i < menu_top + menu_items; ++i) {
+                if (i == menu_top + menu_sel) {
+                    gr_color(255, 255, 255, 255);
+                    draw_text_line(i, menu[i]);
+                    gr_color(64, 96, 255, 255);
+                } else {
+                    draw_text_line(i, menu[i]);
+                }
+            }
+            gr_fill(0, i*CHAR_HEIGHT+CHAR_HEIGHT/2-1,
+                    gr_fb_width(), i*CHAR_HEIGHT+CHAR_HEIGHT/2+1);
+            ++i;
+        }
+
+        gr_color(255, 255, 0, 255);
+
+        for (; i < text_rows; ++i) {
+            draw_text_line(i, text[(i+text_top) % text_rows]);
+        }
+    }
+}
+
+// Redraw everything on the screen and flip the screen (make it visible).
+// Should only be called with updateMutex locked.
+void ScreenRecoveryUI::update_screen_locked()
+{
+    draw_screen_locked();
+    gr_flip();
+}
+
+// Updates only the progress bar, if possible, otherwise redraws the screen.
+// Should only be called with updateMutex locked.
+void ScreenRecoveryUI::update_progress_locked()
+{
+    if (show_text || !pagesIdentical) {
+        draw_screen_locked();    // Must redraw the whole screen
+        pagesIdentical = true;
+    } else {
+        draw_progress_locked();  // Draw only the progress bar and overlays
+    }
+    gr_flip();
+}
+
+// Keeps the progress bar updated, even when the process is otherwise busy.
+void* ScreenRecoveryUI::progress_thread(void *cookie) {
+    self->progress_loop();
+    return NULL;
+}
+
+void ScreenRecoveryUI::progress_loop() {
+    double interval = 1.0 / animation_fps;
+    for (;;) {
+        double start = now();
+        pthread_mutex_lock(&updateMutex);
+
+        int redraw = 0;
+
+        // update the installation animation, if active
+        // skip this if we have a text overlay (too expensive to update)
+        if (currentIcon == INSTALLING && installing_frames > 0 && !show_text) {
+            installingFrame = (installingFrame + 1) % installing_frames;
+            redraw = 1;
+        }
+
+        // update the progress bar animation, if active
+        // skip this if we have a text overlay (too expensive to update)
+        if (progressBarType == INDETERMINATE && !show_text) {
+            redraw = 1;
+        }
+
+        // move the progress bar forward on timed intervals, if configured
+        int duration = progressScopeDuration;
+        if (progressBarType == DETERMINATE && duration > 0) {
+            double elapsed = now() - progressScopeTime;
+            float progress = 1.0 * elapsed / duration;
+            if (progress > 1.0) progress = 1.0;
+            if (progress > progress) {
+                progress = progress;
+                redraw = 1;
+            }
+        }
+
+        if (redraw) update_progress_locked();
+
+        pthread_mutex_unlock(&updateMutex);
+        double end = now();
+        // minimum of 20ms delay between frames
+        double delay = interval - (end-start);
+        if (delay < 0.02) delay = 0.02;
+        usleep((long)(delay * 1000000));
+    }
+}
+
+void ScreenRecoveryUI::LoadBitmap(const char* filename, gr_surface* surface) {
+    int result = res_create_surface(filename, surface);
+    if (result < 0) {
+        LOGE("missing bitmap %s\n(Code %d)\n", filename, result);
+    }
+}
+
+void ScreenRecoveryUI::Init()
+{
+    gr_init();
+
+    text_col = text_row = 0;
+    text_rows = gr_fb_height() / CHAR_HEIGHT;
+    if (text_rows > kMaxRows) text_rows = kMaxRows;
+    text_top = 1;
+
+    text_cols = gr_fb_width() / CHAR_WIDTH;
+    if (text_cols > kMaxCols - 1) text_cols = kMaxCols - 1;
+
+    LoadBitmap("icon_installing", &backgroundIcon[INSTALLING]);
+    LoadBitmap("icon_error", &backgroundIcon[ERROR]);
+    LoadBitmap("progress_empty", &progressBarEmpty);
+    LoadBitmap("progress_fill", &progressBarFill);
+
+    int i;
+
+    progressBarIndeterminate = (gr_surface*)malloc(indeterminate_frames *
+                                                    sizeof(gr_surface));
+    for (i = 0; i < indeterminate_frames; ++i) {
+        char filename[40];
+        // "indeterminate01.png", "indeterminate02.png", ...
+        sprintf(filename, "indeterminate%02d", i+1);
+        LoadBitmap(filename, progressBarIndeterminate+i);
+    }
+
+    if (installing_frames > 0) {
+        installationOverlay = (gr_surface*)malloc(installing_frames *
+                                                   sizeof(gr_surface));
+        for (i = 0; i < installing_frames; ++i) {
+            char filename[40];
+            // "icon_installing_overlay01.png",
+            // "icon_installing_overlay02.png", ...
+            sprintf(filename, "icon_installing_overlay%02d", i+1);
+            LoadBitmap(filename, installationOverlay+i);
+        }
+
+        // Adjust the offset to account for the positioning of the
+        // base image on the screen.
+        if (backgroundIcon[INSTALLING] != NULL) {
+            gr_surface bg = backgroundIcon[INSTALLING];
+            install_overlay_offset_x += (gr_fb_width() - gr_get_width(bg)) / 2;
+            install_overlay_offset_y += (gr_fb_height() - gr_get_height(bg)) / 2;
+        }
+    } else {
+        installationOverlay = NULL;
+    }
+
+    pthread_create(&progress_t, NULL, progress_thread, NULL);
+
+    RecoveryUI::Init();
+}
+
+void ScreenRecoveryUI::SetBackground(Icon icon)
+{
+    pthread_mutex_lock(&updateMutex);
+    currentIcon = icon;
+    update_screen_locked();
+    pthread_mutex_unlock(&updateMutex);
+}
+
+void ScreenRecoveryUI::SetProgressType(ProgressType type)
+{
+    pthread_mutex_lock(&updateMutex);
+    if (progressBarType != type) {
+        progressBarType = type;
+        update_progress_locked();
+    }
+    pthread_mutex_unlock(&updateMutex);
+}
+
+void ScreenRecoveryUI::ShowProgress(float portion, float seconds)
+{
+    pthread_mutex_lock(&updateMutex);
+    progressBarType = DETERMINATE;
+    progressScopeStart += progressScopeSize;
+    progressScopeSize = portion;
+    progressScopeTime = now();
+    progressScopeDuration = seconds;
+    progress = 0;
+    update_progress_locked();
+    pthread_mutex_unlock(&updateMutex);
+}
+
+void ScreenRecoveryUI::SetProgress(float fraction)
+{
+    pthread_mutex_lock(&updateMutex);
+    if (fraction < 0.0) fraction = 0.0;
+    if (fraction > 1.0) fraction = 1.0;
+    if (progressBarType == DETERMINATE && fraction > progress) {
+        // Skip updates that aren't visibly different.
+        int width = gr_get_width(progressBarIndeterminate[0]);
+        float scale = width * progressScopeSize;
+        if ((int) (progress * scale) != (int) (fraction * scale)) {
+            progress = fraction;
+            update_progress_locked();
+        }
+    }
+    pthread_mutex_unlock(&updateMutex);
+}
+
+void ScreenRecoveryUI::Print(const char *fmt, ...)
+{
+    char buf[256];
+    va_list ap;
+    va_start(ap, fmt);
+    vsnprintf(buf, 256, fmt, ap);
+    va_end(ap);
+
+    fputs(buf, stdout);
+
+    // This can get called before ui_init(), so be careful.
+    pthread_mutex_lock(&updateMutex);
+    if (text_rows > 0 && text_cols > 0) {
+        char *ptr;
+        for (ptr = buf; *ptr != '\0'; ++ptr) {
+            if (*ptr == '\n' || text_col >= text_cols) {
+                text[text_row][text_col] = '\0';
+                text_col = 0;
+                text_row = (text_row + 1) % text_rows;
+                if (text_row == text_top) text_top = (text_top + 1) % text_rows;
+            }
+            if (*ptr != '\n') text[text_row][text_col++] = *ptr;
+        }
+        text[text_row][text_col] = '\0';
+        update_screen_locked();
+    }
+    pthread_mutex_unlock(&updateMutex);
+}
+
+void ScreenRecoveryUI::StartMenu(const char* const * headers, const char* const * items,
+                                 int initial_selection) {
+    int i;
+    pthread_mutex_lock(&updateMutex);
+    if (text_rows > 0 && text_cols > 0) {
+        for (i = 0; i < text_rows; ++i) {
+            if (headers[i] == NULL) break;
+            strncpy(menu[i], headers[i], text_cols-1);
+            menu[i][text_cols-1] = '\0';
+        }
+        menu_top = i;
+        for (; i < text_rows; ++i) {
+            if (items[i-menu_top] == NULL) break;
+            strncpy(menu[i], items[i-menu_top], text_cols-1);
+            menu[i][text_cols-1] = '\0';
+        }
+        menu_items = i - menu_top;
+        show_menu = 1;
+        menu_sel = initial_selection;
+        update_screen_locked();
+    }
+    pthread_mutex_unlock(&updateMutex);
+}
+
+int ScreenRecoveryUI::SelectMenu(int sel) {
+    int old_sel;
+    pthread_mutex_lock(&updateMutex);
+    if (show_menu > 0) {
+        old_sel = menu_sel;
+        menu_sel = sel;
+        if (menu_sel < 0) menu_sel = 0;
+        if (menu_sel >= menu_items) menu_sel = menu_items-1;
+        sel = menu_sel;
+        if (menu_sel != old_sel) update_screen_locked();
+    }
+    pthread_mutex_unlock(&updateMutex);
+    return sel;
+}
+
+void ScreenRecoveryUI::EndMenu() {
+    int i;
+    pthread_mutex_lock(&updateMutex);
+    if (show_menu > 0 && text_rows > 0 && text_cols > 0) {
+        show_menu = 0;
+        update_screen_locked();
+    }
+    pthread_mutex_unlock(&updateMutex);
+}
+
+bool ScreenRecoveryUI::IsTextVisible()
+{
+    pthread_mutex_lock(&updateMutex);
+    int visible = show_text;
+    pthread_mutex_unlock(&updateMutex);
+    return visible;
+}
+
+bool ScreenRecoveryUI::WasTextEverVisible()
+{
+    pthread_mutex_lock(&updateMutex);
+    int ever_visible = show_text_ever;
+    pthread_mutex_unlock(&updateMutex);
+    return ever_visible;
+}
+
+void ScreenRecoveryUI::ShowText(bool visible)
+{
+    pthread_mutex_lock(&updateMutex);
+    show_text = visible;
+    if (show_text) show_text_ever = 1;
+    update_screen_locked();
+    pthread_mutex_unlock(&updateMutex);
+}
diff --git a/screen_ui.h b/screen_ui.h
new file mode 100644
index 0000000..34929ee
--- /dev/null
+++ b/screen_ui.h
@@ -0,0 +1,110 @@
+/*
+ * 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.
+ */
+
+#ifndef RECOVERY_SCREEN_UI_H
+#define RECOVERY_SCREEN_UI_H
+
+#include <pthread.h>
+
+#include "ui.h"
+#include "minui/minui.h"
+
+// Implementation of RecoveryUI appropriate for devices with a screen
+// (shows an icon + a progress bar, text logging, menu, etc.)
+class ScreenRecoveryUI : public RecoveryUI {
+  public:
+    ScreenRecoveryUI();
+
+    void Init();
+
+    // overall recovery state ("background image")
+    void SetBackground(Icon icon);
+
+    // progress indicator
+    void SetProgressType(ProgressType type);
+    void ShowProgress(float portion, float seconds);
+    void SetProgress(float fraction);
+
+    // text log
+    void ShowText(bool visible);
+    bool IsTextVisible();
+    bool WasTextEverVisible();
+
+    // printing messages
+    void Print(const char* fmt, ...); // __attribute__((format(printf, 1, 2)));
+
+    // menu display
+    void StartMenu(const char* const * headers, const char* const * items,
+                           int initial_selection);
+    int SelectMenu(int sel);
+    void EndMenu();
+
+  private:
+    Icon currentIcon;
+    int installingFrame;
+
+    pthread_mutex_t updateMutex;
+    gr_surface backgroundIcon[3];
+    gr_surface *installationOverlay;
+    gr_surface *progressBarIndeterminate;
+    gr_surface progressBarEmpty;
+    gr_surface progressBarFill;
+
+    ProgressType progressBarType;
+
+    float progressScopeStart, progressScopeSize, progress;
+    double progressScopeTime, progressScopeDuration;
+
+    // true when both graphics pages are the same (except for the
+    // progress bar)
+    bool pagesIdentical;
+
+    static const int kMaxCols = 96;
+    static const int kMaxRows = 32;
+
+    // Log text overlay, displayed when a magic key is pressed
+    char text[kMaxRows][kMaxCols];
+    int text_cols, text_rows;
+    int text_col, text_row, text_top;
+    bool show_text;
+    bool show_text_ever;   // has show_text ever been true?
+
+    char menu[kMaxRows][kMaxCols];
+    bool show_menu;
+    int menu_top, menu_items, menu_sel;
+
+    pthread_t progress_t;
+
+    int animation_fps;
+    int indeterminate_frames;
+    int installing_frames;
+    int install_overlay_offset_x, install_overlay_offset_y;
+
+    void draw_install_overlay_locked(int frame);
+    void draw_background_locked(Icon icon);
+    void draw_progress_locked();
+    void draw_text_line(int row, const char* t);
+    void draw_screen_locked();
+    void update_screen_locked();
+    void update_progress_locked();
+    static void* progress_thread(void* cookie);
+    void progress_loop();
+
+    void LoadBitmap(const char* filename, gr_surface* surface);
+
+};
+
+#endif  // RECOVERY_UI_H
diff --git a/ui.c b/ui.c
deleted file mode 100644
index 25df3d0..0000000
--- a/ui.c
+++ /dev/null
@@ -1,664 +0,0 @@
-/*
- * Copyright (C) 2007 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 "common.h"
-#include <cutils/android_reboot.h>
-#include "minui/minui.h"
-#include "recovery_ui.h"
-
-#define MAX_COLS 96
-#define MAX_ROWS 32
-
-#define CHAR_WIDTH 10
-#define CHAR_HEIGHT 18
-
-#define UI_WAIT_KEY_TIMEOUT_SEC    120
-
-UIParameters ui_parameters = {
-    6,       // indeterminate progress bar frames
-    20,      // fps
-    7,       // installation icon frames (0 == static image)
-    13, 190, // installation icon overlay offset
-};
-
-static pthread_mutex_t gUpdateMutex = PTHREAD_MUTEX_INITIALIZER;
-static gr_surface gBackgroundIcon[NUM_BACKGROUND_ICONS];
-static gr_surface *gInstallationOverlay;
-static gr_surface *gProgressBarIndeterminate;
-static gr_surface gProgressBarEmpty;
-static gr_surface gProgressBarFill;
-
-static const struct { gr_surface* surface; const char *name; } BITMAPS[] = {
-    { &gBackgroundIcon[BACKGROUND_ICON_INSTALLING], "icon_installing" },
-    { &gBackgroundIcon[BACKGROUND_ICON_ERROR],      "icon_error" },
-    { &gProgressBarEmpty,               "progress_empty" },
-    { &gProgressBarFill,                "progress_fill" },
-    { NULL,                             NULL },
-};
-
-static int gCurrentIcon = 0;
-static int gInstallingFrame = 0;
-
-static enum ProgressBarType {
-    PROGRESSBAR_TYPE_NONE,
-    PROGRESSBAR_TYPE_INDETERMINATE,
-    PROGRESSBAR_TYPE_NORMAL,
-} gProgressBarType = PROGRESSBAR_TYPE_NONE;
-
-// Progress bar scope of current operation
-static float gProgressScopeStart = 0, gProgressScopeSize = 0, gProgress = 0;
-static double gProgressScopeTime, gProgressScopeDuration;
-
-// Set to 1 when both graphics pages are the same (except for the progress bar)
-static int gPagesIdentical = 0;
-
-// Log text overlay, displayed when a magic key is pressed
-static char text[MAX_ROWS][MAX_COLS];
-static int text_cols = 0, text_rows = 0;
-static int text_col = 0, text_row = 0, text_top = 0;
-static int show_text = 0;
-static int show_text_ever = 0;   // has show_text ever been 1?
-
-static char menu[MAX_ROWS][MAX_COLS];
-static int show_menu = 0;
-static int menu_top = 0, menu_items = 0, menu_sel = 0;
-
-// Key event input queue
-static pthread_mutex_t key_queue_mutex = PTHREAD_MUTEX_INITIALIZER;
-static pthread_cond_t key_queue_cond = PTHREAD_COND_INITIALIZER;
-static int key_queue[256], key_queue_len = 0;
-static volatile char key_pressed[KEY_MAX + 1];
-
-// Return the current time as a double (including fractions of a second).
-static double now() {
-    struct timeval tv;
-    gettimeofday(&tv, NULL);
-    return tv.tv_sec + tv.tv_usec / 1000000.0;
-}
-
-// Draw the given frame over the installation overlay animation.  The
-// background is not cleared or draw with the base icon first; we
-// assume that the frame already contains some other frame of the
-// animation.  Does nothing if no overlay animation is defined.
-// Should only be called with gUpdateMutex locked.
-static void draw_install_overlay_locked(int frame) {
-    if (gInstallationOverlay == NULL) return;
-    gr_surface surface = gInstallationOverlay[frame];
-    int iconWidth = gr_get_width(surface);
-    int iconHeight = gr_get_height(surface);
-    gr_blit(surface, 0, 0, iconWidth, iconHeight,
-            ui_parameters.install_overlay_offset_x,
-            ui_parameters.install_overlay_offset_y);
-}
-
-// Clear the screen and draw the currently selected background icon (if any).
-// Should only be called with gUpdateMutex locked.
-static void draw_background_locked(int icon)
-{
-    gPagesIdentical = 0;
-    gr_color(0, 0, 0, 255);
-    gr_fill(0, 0, gr_fb_width(), gr_fb_height());
-
-    if (icon) {
-        gr_surface surface = gBackgroundIcon[icon];
-        int iconWidth = gr_get_width(surface);
-        int iconHeight = gr_get_height(surface);
-        int iconX = (gr_fb_width() - iconWidth) / 2;
-        int iconY = (gr_fb_height() - iconHeight) / 2;
-        gr_blit(surface, 0, 0, iconWidth, iconHeight, iconX, iconY);
-        if (icon == BACKGROUND_ICON_INSTALLING) {
-            draw_install_overlay_locked(gInstallingFrame);
-        }
-    }
-}
-
-// Draw the progress bar (if any) on the screen.  Does not flip pages.
-// Should only be called with gUpdateMutex locked.
-static void draw_progress_locked()
-{
-    if (gCurrentIcon == BACKGROUND_ICON_INSTALLING) {
-        draw_install_overlay_locked(gInstallingFrame);
-    }
-
-    if (gProgressBarType != PROGRESSBAR_TYPE_NONE) {
-        int iconHeight = gr_get_height(gBackgroundIcon[BACKGROUND_ICON_INSTALLING]);
-        int width = gr_get_width(gProgressBarEmpty);
-        int height = gr_get_height(gProgressBarEmpty);
-
-        int dx = (gr_fb_width() - width)/2;
-        int dy = (3*gr_fb_height() + iconHeight - 2*height)/4;
-
-        // Erase behind the progress bar (in case this was a progress-only update)
-        gr_color(0, 0, 0, 255);
-        gr_fill(dx, dy, width, height);
-
-        if (gProgressBarType == PROGRESSBAR_TYPE_NORMAL) {
-            float progress = gProgressScopeStart + gProgress * gProgressScopeSize;
-            int pos = (int) (progress * width);
-
-            if (pos > 0) {
-                gr_blit(gProgressBarFill, 0, 0, pos, height, dx, dy);
-            }
-            if (pos < width-1) {
-                gr_blit(gProgressBarEmpty, pos, 0, width-pos, height, dx+pos, dy);
-            }
-        }
-
-        if (gProgressBarType == PROGRESSBAR_TYPE_INDETERMINATE) {
-            static int frame = 0;
-            gr_blit(gProgressBarIndeterminate[frame], 0, 0, width, height, dx, dy);
-            frame = (frame + 1) % ui_parameters.indeterminate_frames;
-        }
-    }
-}
-
-static void draw_text_line(int row, const char* t) {
-  if (t[0] != '\0') {
-    gr_text(0, (row+1)*CHAR_HEIGHT-1, t);
-  }
-}
-
-// Redraw everything on the screen.  Does not flip pages.
-// Should only be called with gUpdateMutex locked.
-static void draw_screen_locked(void)
-{
-    draw_background_locked(gCurrentIcon);
-    draw_progress_locked();
-
-    if (show_text) {
-        gr_color(0, 0, 0, 160);
-        gr_fill(0, 0, gr_fb_width(), gr_fb_height());
-
-        int i = 0;
-        if (show_menu) {
-            gr_color(64, 96, 255, 255);
-            gr_fill(0, (menu_top+menu_sel) * CHAR_HEIGHT,
-                    gr_fb_width(), (menu_top+menu_sel+1)*CHAR_HEIGHT+1);
-
-            for (; i < menu_top + menu_items; ++i) {
-                if (i == menu_top + menu_sel) {
-                    gr_color(255, 255, 255, 255);
-                    draw_text_line(i, menu[i]);
-                    gr_color(64, 96, 255, 255);
-                } else {
-                    draw_text_line(i, menu[i]);
-                }
-            }
-            gr_fill(0, i*CHAR_HEIGHT+CHAR_HEIGHT/2-1,
-                    gr_fb_width(), i*CHAR_HEIGHT+CHAR_HEIGHT/2+1);
-            ++i;
-        }
-
-        gr_color(255, 255, 0, 255);
-
-        for (; i < text_rows; ++i) {
-            draw_text_line(i, text[(i+text_top) % text_rows]);
-        }
-    }
-}
-
-// Redraw everything on the screen and flip the screen (make it visible).
-// Should only be called with gUpdateMutex locked.
-static void update_screen_locked(void)
-{
-    draw_screen_locked();
-    gr_flip();
-}
-
-// Updates only the progress bar, if possible, otherwise redraws the screen.
-// Should only be called with gUpdateMutex locked.
-static void update_progress_locked(void)
-{
-    if (show_text || !gPagesIdentical) {
-        draw_screen_locked();    // Must redraw the whole screen
-        gPagesIdentical = 1;
-    } else {
-        draw_progress_locked();  // Draw only the progress bar and overlays
-    }
-    gr_flip();
-}
-
-// Keeps the progress bar updated, even when the process is otherwise busy.
-static void *progress_thread(void *cookie)
-{
-    double interval = 1.0 / ui_parameters.update_fps;
-    for (;;) {
-        double start = now();
-        pthread_mutex_lock(&gUpdateMutex);
-
-        int redraw = 0;
-
-        // update the installation animation, if active
-        // skip this if we have a text overlay (too expensive to update)
-        if (gCurrentIcon == BACKGROUND_ICON_INSTALLING &&
-            ui_parameters.installing_frames > 0 &&
-            !show_text) {
-            gInstallingFrame =
-                (gInstallingFrame + 1) % ui_parameters.installing_frames;
-            redraw = 1;
-        }
-
-        // update the progress bar animation, if active
-        // skip this if we have a text overlay (too expensive to update)
-        if (gProgressBarType == PROGRESSBAR_TYPE_INDETERMINATE && !show_text) {
-            redraw = 1;
-        }
-
-        // move the progress bar forward on timed intervals, if configured
-        int duration = gProgressScopeDuration;
-        if (gProgressBarType == PROGRESSBAR_TYPE_NORMAL && duration > 0) {
-            double elapsed = now() - gProgressScopeTime;
-            float progress = 1.0 * elapsed / duration;
-            if (progress > 1.0) progress = 1.0;
-            if (progress > gProgress) {
-                gProgress = progress;
-                redraw = 1;
-            }
-        }
-
-        if (redraw) update_progress_locked();
-
-        pthread_mutex_unlock(&gUpdateMutex);
-        double end = now();
-        // minimum of 20ms delay between frames
-        double delay = interval - (end-start);
-        if (delay < 0.02) delay = 0.02;
-        usleep((long)(delay * 1000000));
-    }
-    return NULL;
-}
-
-static int rel_sum = 0;
-
-static int input_callback(int fd, short revents, void *data)
-{
-    struct input_event ev;
-    int ret;
-    int fake_key = 0;
-
-    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.
-            rel_sum += ev.value;
-            if (rel_sum > 3) {
-                fake_key = 1;
-                ev.type = EV_KEY;
-                ev.code = KEY_DOWN;
-                ev.value = 1;
-                rel_sum = 0;
-            } else if (rel_sum < -3) {
-                fake_key = 1;
-                ev.type = EV_KEY;
-                ev.code = KEY_UP;
-                ev.value = 1;
-                rel_sum = 0;
-            }
-        }
-    } else {
-        rel_sum = 0;
-    }
-
-    if (ev.type != EV_KEY || ev.code > KEY_MAX)
-        return 0;
-
-    pthread_mutex_lock(&key_queue_mutex);
-    if (!fake_key) {
-        // our "fake" keys only report a key-down event (no
-        // key-up), so don't record them in the key_pressed
-        // table.
-        key_pressed[ev.code] = ev.value;
-    }
-    const int queue_max = sizeof(key_queue) / sizeof(key_queue[0]);
-    if (ev.value > 0 && key_queue_len < queue_max) {
-        key_queue[key_queue_len++] = ev.code;
-        pthread_cond_signal(&key_queue_cond);
-    }
-    pthread_mutex_unlock(&key_queue_mutex);
-
-    if (ev.value > 0 && device_toggle_display(key_pressed, ev.code)) {
-        pthread_mutex_lock(&gUpdateMutex);
-        show_text = !show_text;
-        if (show_text) show_text_ever = 1;
-        update_screen_locked();
-        pthread_mutex_unlock(&gUpdateMutex);
-    }
-
-    if (ev.value > 0 && device_reboot_now(key_pressed, ev.code)) {
-        android_reboot(ANDROID_RB_RESTART, 0, 0);
-    }
-
-    return 0;
-}
-
-// Reads input events, handles special hot keys, and adds to the key queue.
-static void *input_thread(void *cookie)
-{
-    for (;;) {
-        if (!ev_wait(-1))
-            ev_dispatch();
-    }
-    return NULL;
-}
-
-void ui_init(void)
-{
-    gr_init();
-    ev_init(input_callback, NULL);
-
-    text_col = text_row = 0;
-    text_rows = gr_fb_height() / CHAR_HEIGHT;
-    if (text_rows > MAX_ROWS) text_rows = MAX_ROWS;
-    text_top = 1;
-
-    text_cols = gr_fb_width() / CHAR_WIDTH;
-    if (text_cols > MAX_COLS - 1) text_cols = MAX_COLS - 1;
-
-    int i;
-    for (i = 0; BITMAPS[i].name != NULL; ++i) {
-        int result = res_create_surface(BITMAPS[i].name, BITMAPS[i].surface);
-        if (result < 0) {
-            LOGE("Missing bitmap %s\n(Code %d)\n", BITMAPS[i].name, result);
-        }
-    }
-
-    gProgressBarIndeterminate = malloc(ui_parameters.indeterminate_frames *
-                                       sizeof(gr_surface));
-    for (i = 0; i < ui_parameters.indeterminate_frames; ++i) {
-        char filename[40];
-        // "indeterminate01.png", "indeterminate02.png", ...
-        sprintf(filename, "indeterminate%02d", i+1);
-        int result = res_create_surface(filename, gProgressBarIndeterminate+i);
-        if (result < 0) {
-            LOGE("Missing bitmap %s\n(Code %d)\n", filename, result);
-        }
-    }
-
-    if (ui_parameters.installing_frames > 0) {
-        gInstallationOverlay = malloc(ui_parameters.installing_frames *
-                                      sizeof(gr_surface));
-        for (i = 0; i < ui_parameters.installing_frames; ++i) {
-            char filename[40];
-            // "icon_installing_overlay01.png",
-            // "icon_installing_overlay02.png", ...
-            sprintf(filename, "icon_installing_overlay%02d", i+1);
-            int result = res_create_surface(filename, gInstallationOverlay+i);
-            if (result < 0) {
-                LOGE("Missing bitmap %s\n(Code %d)\n", filename, result);
-            }
-        }
-
-        // Adjust the offset to account for the positioning of the
-        // base image on the screen.
-        if (gBackgroundIcon[BACKGROUND_ICON_INSTALLING] != NULL) {
-            gr_surface bg = gBackgroundIcon[BACKGROUND_ICON_INSTALLING];
-            ui_parameters.install_overlay_offset_x +=
-                (gr_fb_width() - gr_get_width(bg)) / 2;
-            ui_parameters.install_overlay_offset_y +=
-                (gr_fb_height() - gr_get_height(bg)) / 2;
-        }
-    } else {
-        gInstallationOverlay = NULL;
-    }
-
-    pthread_t t;
-    pthread_create(&t, NULL, progress_thread, NULL);
-    pthread_create(&t, NULL, input_thread, NULL);
-}
-
-void ui_set_background(int icon)
-{
-    pthread_mutex_lock(&gUpdateMutex);
-    gCurrentIcon = icon;
-    update_screen_locked();
-    pthread_mutex_unlock(&gUpdateMutex);
-}
-
-void ui_show_indeterminate_progress()
-{
-    pthread_mutex_lock(&gUpdateMutex);
-    if (gProgressBarType != PROGRESSBAR_TYPE_INDETERMINATE) {
-        gProgressBarType = PROGRESSBAR_TYPE_INDETERMINATE;
-        update_progress_locked();
-    }
-    pthread_mutex_unlock(&gUpdateMutex);
-}
-
-void ui_show_progress(float portion, int seconds)
-{
-    pthread_mutex_lock(&gUpdateMutex);
-    gProgressBarType = PROGRESSBAR_TYPE_NORMAL;
-    gProgressScopeStart += gProgressScopeSize;
-    gProgressScopeSize = portion;
-    gProgressScopeTime = now();
-    gProgressScopeDuration = seconds;
-    gProgress = 0;
-    update_progress_locked();
-    pthread_mutex_unlock(&gUpdateMutex);
-}
-
-void ui_set_progress(float fraction)
-{
-    pthread_mutex_lock(&gUpdateMutex);
-    if (fraction < 0.0) fraction = 0.0;
-    if (fraction > 1.0) fraction = 1.0;
-    if (gProgressBarType == PROGRESSBAR_TYPE_NORMAL && fraction > gProgress) {
-        // Skip updates that aren't visibly different.
-        int width = gr_get_width(gProgressBarIndeterminate[0]);
-        float scale = width * gProgressScopeSize;
-        if ((int) (gProgress * scale) != (int) (fraction * scale)) {
-            gProgress = fraction;
-            update_progress_locked();
-        }
-    }
-    pthread_mutex_unlock(&gUpdateMutex);
-}
-
-void ui_reset_progress()
-{
-    pthread_mutex_lock(&gUpdateMutex);
-    gProgressBarType = PROGRESSBAR_TYPE_NONE;
-    gProgressScopeStart = gProgressScopeSize = 0;
-    gProgressScopeTime = gProgressScopeDuration = 0;
-    gProgress = 0;
-    update_screen_locked();
-    pthread_mutex_unlock(&gUpdateMutex);
-}
-
-void ui_print(const char *fmt, ...)
-{
-    char buf[256];
-    va_list ap;
-    va_start(ap, fmt);
-    vsnprintf(buf, 256, fmt, ap);
-    va_end(ap);
-
-    fputs(buf, stdout);
-
-    // This can get called before ui_init(), so be careful.
-    pthread_mutex_lock(&gUpdateMutex);
-    if (text_rows > 0 && text_cols > 0) {
-        char *ptr;
-        for (ptr = buf; *ptr != '\0'; ++ptr) {
-            if (*ptr == '\n' || text_col >= text_cols) {
-                text[text_row][text_col] = '\0';
-                text_col = 0;
-                text_row = (text_row + 1) % text_rows;
-                if (text_row == text_top) text_top = (text_top + 1) % text_rows;
-            }
-            if (*ptr != '\n') text[text_row][text_col++] = *ptr;
-        }
-        text[text_row][text_col] = '\0';
-        update_screen_locked();
-    }
-    pthread_mutex_unlock(&gUpdateMutex);
-}
-
-void ui_start_menu(char** headers, char** items, int initial_selection) {
-    int i;
-    pthread_mutex_lock(&gUpdateMutex);
-    if (text_rows > 0 && text_cols > 0) {
-        for (i = 0; i < text_rows; ++i) {
-            if (headers[i] == NULL) break;
-            strncpy(menu[i], headers[i], text_cols-1);
-            menu[i][text_cols-1] = '\0';
-        }
-        menu_top = i;
-        for (; i < text_rows; ++i) {
-            if (items[i-menu_top] == NULL) break;
-            strncpy(menu[i], items[i-menu_top], text_cols-1);
-            menu[i][text_cols-1] = '\0';
-        }
-        menu_items = i - menu_top;
-        show_menu = 1;
-        menu_sel = initial_selection;
-        update_screen_locked();
-    }
-    pthread_mutex_unlock(&gUpdateMutex);
-}
-
-int ui_menu_select(int sel) {
-    int old_sel;
-    pthread_mutex_lock(&gUpdateMutex);
-    if (show_menu > 0) {
-        old_sel = menu_sel;
-        menu_sel = sel;
-        if (menu_sel < 0) menu_sel = 0;
-        if (menu_sel >= menu_items) menu_sel = menu_items-1;
-        sel = menu_sel;
-        if (menu_sel != old_sel) update_screen_locked();
-    }
-    pthread_mutex_unlock(&gUpdateMutex);
-    return sel;
-}
-
-void ui_end_menu() {
-    int i;
-    pthread_mutex_lock(&gUpdateMutex);
-    if (show_menu > 0 && text_rows > 0 && text_cols > 0) {
-        show_menu = 0;
-        update_screen_locked();
-    }
-    pthread_mutex_unlock(&gUpdateMutex);
-}
-
-int ui_text_visible()
-{
-    pthread_mutex_lock(&gUpdateMutex);
-    int visible = show_text;
-    pthread_mutex_unlock(&gUpdateMutex);
-    return visible;
-}
-
-int ui_text_ever_visible()
-{
-    pthread_mutex_lock(&gUpdateMutex);
-    int ever_visible = show_text_ever;
-    pthread_mutex_unlock(&gUpdateMutex);
-    return ever_visible;
-}
-
-void ui_show_text(int visible)
-{
-    pthread_mutex_lock(&gUpdateMutex);
-    show_text = visible;
-    if (show_text) show_text_ever = 1;
-    update_screen_locked();
-    pthread_mutex_unlock(&gUpdateMutex);
-}
-
-// Return true if USB is connected.
-static int 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;
-}
-
-int ui_wait_key()
-{
-    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;
-}
-
-int ui_key_pressed(int key)
-{
-    // This is a volatile static array, don't bother locking
-    return key_pressed[key];
-}
-
-void ui_clear_key_queue() {
-    pthread_mutex_lock(&key_queue_mutex);
-    key_queue_len = 0;
-    pthread_mutex_unlock(&key_queue_mutex);
-}
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;
+}
diff --git a/ui.h b/ui.h
new file mode 100644
index 0000000..750b993
--- /dev/null
+++ b/ui.h
@@ -0,0 +1,112 @@
+/*
+ * 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.
+ */
+
+#ifndef RECOVERY_UI_H
+#define RECOVERY_UI_H
+
+#include <linux/input.h>
+#include <pthread.h>
+
+// Abstract class for controlling the user interface during recovery.
+class RecoveryUI {
+  public:
+    RecoveryUI();
+
+    virtual ~RecoveryUI() { }
+
+    // Initialize the object; called before anything else.
+    virtual void Init();
+
+    // Set the overall recovery state ("background image").
+    enum Icon { NONE, INSTALLING, ERROR };
+    virtual void SetBackground(Icon icon) = 0;
+
+    // --- progress indicator ---
+    enum ProgressType { EMPTY, INDETERMINATE, DETERMINATE };
+    virtual void SetProgressType(ProgressType determinate) = 0;
+
+    // Show a progress bar and define the scope of the next operation:
+    //   portion - fraction of the progress bar the next operation will use
+    //   seconds - expected time interval (progress bar moves at this minimum rate)
+    virtual void ShowProgress(float portion, float seconds) = 0;
+
+    // Set progress bar position (0.0 - 1.0 within the scope defined
+    // by the last call to ShowProgress).
+    virtual void SetProgress(float fraction) = 0;
+
+    // --- text log ---
+
+    virtual void ShowText(bool visible) = 0;
+
+    virtual bool IsTextVisible() = 0;
+
+    virtual bool WasTextEverVisible() = 0;
+
+    // Write a message to the on-screen log (shown if the user has
+    // toggled on the text display).
+    virtual void Print(const char* fmt, ...) = 0; // __attribute__((format(printf, 1, 2))) = 0;
+
+    // --- key handling ---
+
+    // Wait for keypress and return it.  May return -1 after timeout.
+    virtual int WaitKey();
+
+    virtual bool IsKeyPressed(int key);
+
+    // Erase any queued-up keys.
+    virtual void FlushKeys();
+
+    // Called on each keypress, even while operations are in progress.
+    // Return value indicates whether an immediate operation should be
+    // triggered (toggling the display, rebooting the device), or if
+    // the key should be enqueued for use by the main thread.
+    enum KeyAction { ENQUEUE, TOGGLE, REBOOT };
+    virtual KeyAction CheckKey(int key);
+
+    // --- menu display ---
+
+    // Display some header text followed by a menu of items, which appears
+    // at the top of the screen (in place of any scrolling ui_print()
+    // output, if necessary).
+    virtual void StartMenu(const char* const * headers, const char* const * items,
+                           int initial_selection) = 0;
+
+    // Set the menu highlight to the given index, and return it (capped to
+    // the range [0..numitems).
+    virtual int SelectMenu(int sel) = 0;
+
+    // End menu mode, resetting the text overlay so that ui_print()
+    // statements will be displayed.
+    virtual void EndMenu() = 0;
+
+private:
+    // Key event input queue
+    pthread_mutex_t key_queue_mutex;
+    pthread_cond_t key_queue_cond;
+    int key_queue[256], key_queue_len;
+    char key_pressed[KEY_MAX + 1];     // under key_queue_mutex
+    int key_last_down;                 // under key_queue_mutex
+    int rel_sum;
+
+    pthread_t input_t;
+
+    static void* input_thread(void* cookie);
+    static int input_callback(int fd, short revents, void* data);
+    void process_key(int key_code, int updown);
+    bool usb_connected();
+};
+
+#endif  // RECOVERY_UI_H
diff --git a/updater/install.c b/updater/install.c
index 7b4b99b..f68bd03 100644
--- a/updater/install.c
+++ b/updater/install.c
@@ -792,11 +792,12 @@
         return NULL;
     }
 
+    char* partition = NULL;
     if (partition_value->type != VAL_STRING) {
         ErrorAbort(state, "partition argument to %s must be string", name);
         goto done;
     }
-    char* partition = partition_value->data;
+    partition = partition_value->data;
     if (strlen(partition) == 0) {
         ErrorAbort(state, "partition argument to %s can't be empty", name);
         goto done;
diff --git a/verifier.c b/verifier.cpp
similarity index 93%
rename from verifier.c
rename to verifier.cpp
index 729e085..1c5a41d 100644
--- a/verifier.c
+++ b/verifier.cpp
@@ -16,6 +16,7 @@
 
 #include "common.h"
 #include "verifier.h"
+#include "ui.h"
 
 #include "mincrypt/rsa.h"
 #include "mincrypt/sha.h"
@@ -24,6 +25,8 @@
 #include <stdio.h>
 #include <errno.h>
 
+extern RecoveryUI* ui;
+
 // Look for an RSA signature embedded in the .ZIP file comment given
 // the path to the zip.  Verify it matches one of the given public
 // keys.
@@ -32,7 +35,7 @@
 // or no key matches the signature).
 
 int verify_file(const char* path, const RSAPublicKey *pKeys, unsigned int numKeys) {
-    ui_set_progress(0.0);
+    ui->SetProgress(0.0);
 
     FILE* f = fopen(path, "rb");
     if (f == NULL) {
@@ -69,8 +72,8 @@
         return VERIFY_FAILURE;
     }
 
-    int comment_size = footer[4] + (footer[5] << 8);
-    int signature_start = footer[0] + (footer[1] << 8);
+    size_t comment_size = footer[4] + (footer[5] << 8);
+    size_t signature_start = footer[0] + (footer[1] << 8);
     LOGI("comment is %d bytes; signature %d bytes from end\n",
          comment_size, signature_start);
 
@@ -99,7 +102,7 @@
     // bytes) and the comment data.
     size_t signed_len = ftell(f) + EOCD_HEADER_SIZE - 2;
 
-    unsigned char* eocd = malloc(eocd_size);
+    unsigned char* eocd = (unsigned char*)malloc(eocd_size);
     if (eocd == NULL) {
         LOGE("malloc for EOCD record failed\n");
         fclose(f);
@@ -120,7 +123,7 @@
         return VERIFY_FAILURE;
     }
 
-    int i;
+    size_t i;
     for (i = 4; i < eocd_size-3; ++i) {
         if (eocd[i  ] == 0x50 && eocd[i+1] == 0x4b &&
             eocd[i+2] == 0x05 && eocd[i+3] == 0x06) {
@@ -138,7 +141,7 @@
 
     SHA_CTX ctx;
     SHA_init(&ctx);
-    unsigned char* buffer = malloc(BUFFER_SIZE);
+    unsigned char* buffer = (unsigned char*)malloc(BUFFER_SIZE);
     if (buffer == NULL) {
         LOGE("failed to alloc memory for sha1 buffer\n");
         fclose(f);
@@ -149,7 +152,7 @@
     size_t so_far = 0;
     fseek(f, 0, SEEK_SET);
     while (so_far < signed_len) {
-        int size = BUFFER_SIZE;
+        size_t size = BUFFER_SIZE;
         if (signed_len - so_far < size) size = signed_len - so_far;
         if (fread(buffer, 1, size, f) != size) {
             LOGE("failed to read data from %s (%s)\n", path, strerror(errno));
@@ -160,7 +163,7 @@
         so_far += size;
         double f = so_far / (double)signed_len;
         if (f > frac + 0.02 || size == so_far) {
-            ui_set_progress(f);
+            ui->SetProgress(f);
             frac = f;
         }
     }
diff --git a/verifier_test.c b/verifier_test.cpp
similarity index 76%
rename from verifier_test.c
rename to verifier_test.cpp
index 5b6c1f4..fe5519d 100644
--- a/verifier_test.c
+++ b/verifier_test.cpp
@@ -19,6 +19,7 @@
 #include <stdarg.h>
 
 #include "verifier.h"
+#include "ui.h"
 
 // This is build/target/product/security/testkey.x509.pem after being
 // dumped out by dumpkey.jar.
@@ -58,18 +59,36 @@
         367251975, 810756730, -1941182952, 1175080310 }
     };
 
-void ui_print(const char* fmt, ...) {
-    char buf[256];
-    va_list ap;
-    va_start(ap, fmt);
-    vsnprintf(buf, 256, fmt, ap);
-    va_end(ap);
+RecoveryUI* ui = NULL;
 
-    fputs(buf, stderr);
-}
+// verifier expects to find a UI object; we provide one that does
+// nothing but print.
+class FakeUI : public RecoveryUI {
+    void Init() { }
+    void SetBackground(Icon icon) { }
 
-void ui_set_progress(float fraction) {
-}
+    void SetProgressType(ProgressType determinate) { }
+    void ShowProgress(float portion, float seconds) { }
+    void SetProgress(float fraction) { }
+
+    void ShowText(bool visible) { }
+    bool IsTextVisible() { return false; }
+    bool WasTextEverVisible() { return false; }
+    void Print(const char* fmt, ...) {
+        char buf[256];
+        va_list ap;
+        va_start(ap, fmt);
+        vsnprintf(buf, 256, fmt, ap);
+        va_end(ap);
+
+        fputs(buf, stderr);
+    }
+
+    void StartMenu(const char* const * headers, const char* const * items,
+                           int initial_selection) { }
+    int SelectMenu(int sel) { return 0; }
+    void EndMenu() { }
+};
 
 int main(int argc, char **argv) {
     if (argc != 2) {
@@ -77,6 +96,8 @@
         return 2;
     }
 
+    ui = new FakeUI();
+
     int result = verify_file(argv[1], &test_key, 1);
     if (result == VERIFY_SUCCESS) {
         printf("SUCCESS\n");
diff --git a/verifier_test.sh b/verifier_test.sh
index 6350e80..a1de5c5 100755
--- a/verifier_test.sh
+++ b/verifier_test.sh
@@ -1,11 +1,7 @@
 #!/bin/bash
 #
-# A test suite for applypatch.  Run in a client where you have done
-# envsetup, choosecombo, etc.
-#
-# DO NOT RUN THIS ON A DEVICE YOU CARE ABOUT.  It will mess up your
-# system partition.
-#
+# A test suite for recovery's package signature verifier.  Run in a
+# client where you have done envsetup, lunch, etc.
 #
 # TODO: find some way to get this run regularly along with the rest of
 # the tests.