diff --git a/install.cpp b/install.cpp
new file mode 100644
index 0000000..482e0d7
--- /dev/null
+++ b/install.cpp
@@ -0,0 +1,314 @@
+/*
+ * 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 <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "common.h"
+#include "install.h"
+#include "mincrypt/rsa.h"
+#include "minui/minui.h"
+#include "minzip/SysUtil.h"
+#include "minzip/Zip.h"
+#include "mtdutils/mounts.h"
+#include "mtdutils/mtdutils.h"
+#include "roots.h"
+#include "verifier.h"
+#include "ui.h"
+
+#define ASSUMED_UPDATE_BINARY_NAME  "META-INF/com/google/android/update-binary"
+#define PUBLIC_KEYS_FILE "/res/keys"
+
+// 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) {
+    const ZipEntry* binary_entry =
+            mzFindZipEntry(zip, ASSUMED_UPDATE_BINARY_NAME);
+    if (binary_entry == NULL) {
+        mzCloseZipArchive(zip);
+        return INSTALL_CORRUPT;
+    }
+
+    const char* binary = "/tmp/update_binary";
+    unlink(binary);
+    int fd = creat(binary, 0755);
+    if (fd < 0) {
+        mzCloseZipArchive(zip);
+        LOGE("Can't make %s\n", binary);
+        return INSTALL_ERROR;
+    }
+    bool ok = mzExtractZipEntryToFile(zip, binary_entry, fd);
+    close(fd);
+    mzCloseZipArchive(zip);
+
+    if (!ok) {
+        LOGE("Can't copy %s\n", ASSUMED_UPDATE_BINARY_NAME);
+        return INSTALL_ERROR;
+    }
+
+    int pipefd[2];
+    pipe(pipefd);
+
+    // When executing the update binary contained in the package, the
+    // arguments passed are:
+    //
+    //   - the version number for this interface
+    //
+    //   - an fd to which the program can write in order to update the
+    //     progress bar.  The program can write single-line commands:
+    //
+    //        progress <frac> <secs>
+    //            fill up the next <frac> part of of the progress bar
+    //            over <secs> seconds.  If <secs> is zero, use
+    //            set_progress commands to manually control the
+    //            progress of this segment of the bar
+    //
+    //        set_progress <frac>
+    //            <frac> should be between 0.0 and 1.0; sets the
+    //            progress bar within the segment defined by the most
+    //            recent progress command.
+    //
+    //        firmware <"hboot"|"radio"> <filename>
+    //            arrange to install the contents of <filename> in the
+    //            given partition on reboot.
+    //
+    //            (API v2: <filename> may start with "PACKAGE:" to
+    //            indicate taking a file from the OTA package.)
+    //
+    //            (API v3: this command no longer exists.)
+    //
+    //        ui_print <string>
+    //            display <string> on the screen.
+    //
+    //   - the name of the package zip file.
+    //
+
+    const char** args = (const char**)malloc(sizeof(char*) * 5);
+    args[0] = binary;
+    args[1] = EXPAND(RECOVERY_API_VERSION);   // defined in Android.mk
+    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, (char* const*)args);
+        fprintf(stdout, "E:Can't run %s (%s)\n", binary, strerror(errno));
+        _exit(-1);
+    }
+    close(pipefd[1]);
+
+    *wipe_cache = 0;
+
+    char buffer[1024];
+    FILE* from_child = fdopen(pipefd[0], "r");
+    while (fgets(buffer, sizeof(buffer), from_child) != NULL) {
+        char* command = strtok(buffer, " \n");
+        if (command == NULL) {
+            continue;
+        } else if (strcmp(command, "progress") == 0) {
+            char* fraction_s = strtok(NULL, " \n");
+            char* seconds_s = strtok(NULL, " \n");
+
+            float fraction = strtof(fraction_s, NULL);
+            int seconds = strtol(seconds_s, NULL, 10);
+
+            ui_show_progress(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);
+        } else if (strcmp(command, "ui_print") == 0) {
+            char* str = strtok(NULL, "\n");
+            if (str) {
+                ui_print("%s", str);
+            } else {
+                ui_print("\n");
+            }
+        } else if (strcmp(command, "wipe_cache") == 0) {
+            *wipe_cache = 1;
+        } else {
+            LOGE("unknown command [%s]\n", command);
+        }
+    }
+    fclose(from_child);
+
+    int status;
+    waitpid(pid, &status, 0);
+    if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+        LOGE("Error in %s\n(Status %d)\n", path, WEXITSTATUS(status));
+        return INSTALL_ERROR;
+    }
+
+    return INSTALL_SUCCESS;
+}
+
+// Reads a file containing one or more public keys as produced by
+// DumpPublicKey:  this is an RSAPublicKey struct as it would appear
+// as a C source literal, eg:
+//
+//  "{64,0xc926ad21,{1795090719,...,-695002876},{-857949815,...,1175080310}}"
+//
+// (Note that the braces and commas in this example are actual
+// characters the parser expects to find in the file; the ellipses
+// indicate more numbers omitted from this example.)
+//
+// The file may contain multiple keys in this format, separated by
+// commas.  The last key must not be followed by a comma.
+//
+// Returns NULL if the file failed to parse, or if it contain zero keys.
+static RSAPublicKey*
+load_keys(const char* filename, int* numKeys) {
+    RSAPublicKey* out = NULL;
+    *numKeys = 0;
+
+    FILE* f = fopen(filename, "r");
+    if (f == NULL) {
+        LOGE("opening %s: %s\n", filename, strerror(errno));
+        goto exit;
+    }
+
+    {
+        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)) {
+            case ',':
+                // more keys to come.
+                break;
+
+            case EOF:
+                done = true;
+                break;
+
+            default:
+                LOGE("unexpected character between keys\n");
+                goto exit;
+            }
+        }
+    }
+
+    fclose(f);
+    return out;
+
+exit:
+    if (f) fclose(f);
+    free(out);
+    *numKeys = 0;
+    return NULL;
+}
+
+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();
+    LOGI("Update location: %s\n", path);
+
+    if (ensure_path_mounted(path) != 0) {
+        LOGE("Can't mount %s\n", path);
+        return INSTALL_CORRUPT;
+    }
+
+    ui_print("Opening update package...\n");
+
+    int numKeys;
+    RSAPublicKey* loadedKeys = load_keys(PUBLIC_KEYS_FILE, &numKeys);
+    if (loadedKeys == NULL) {
+        LOGE("Failed to load keys\n");
+        return INSTALL_CORRUPT;
+    }
+    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);
+
+    int err;
+    err = verify_file(path, loadedKeys, numKeys);
+    free(loadedKeys);
+    LOGI("verify_file returned %d\n", err);
+    if (err != VERIFY_SUCCESS) {
+        LOGE("signature verification failed\n");
+        return INSTALL_CORRUPT;
+    }
+
+    /* Try to open the package.
+     */
+    ZipArchive zip;
+    err = mzOpenZipArchive(path, &zip);
+    if (err != 0) {
+        LOGE("Can't open %s\n(%s)\n", path, err != -1 ? strerror(err) : "bad");
+        return INSTALL_CORRUPT;
+    }
+
+    /* Verify and install the contents of the package.
+     */
+    ui_print("Installing update...\n");
+    return try_update_binary(path, &zip, wipe_cache);
+}
+
+int
+install_package(const char* path, int* wipe_cache, const char* install_file)
+{
+    FILE* install_log = fopen_path(install_file, "w");
+    if (install_log) {
+        fputs(path, install_log);
+        fputc('\n', install_log);
+    } else {
+        LOGE("failed to open last_install: %s\n", strerror(errno));
+    }
+    int result = really_install_package(path, wipe_cache);
+    if (install_log) {
+        fputc(result == INSTALL_SUCCESS ? '1' : '0', install_log);
+        fputc('\n', install_log);
+        fclose(install_log);
+    }
+    return result;
+}