auto import from //depot/cupcake/@135843
diff --git a/adb/remount_service.c b/adb/remount_service.c
new file mode 100644
index 0000000..26bc841
--- /dev/null
+++ b/adb/remount_service.c
@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2008 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 <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/mount.h>
+#include <errno.h>
+
+#include "sysdeps.h"
+
+#define TRACE_TAG TRACE_ADB
+#include "adb.h"
+
+
+static int system_ro = 1;
+
+/* Returns the mount number of the requested partition from /proc/mtd */
+static int find_mount(const char *findme)
+{
+ int fd;
+ int res;
+ int size;
+ char *token = NULL;
+ const char delims[] = "\n";
+ char buf[1024];
+
+ fd = unix_open("/proc/mtd", O_RDONLY);
+ if (fd < 0)
+ return -errno;
+
+ buf[sizeof(buf) - 1] = '\0';
+ size = adb_read(fd, buf, sizeof(buf) - 1);
+ adb_close(fd);
+
+ token = strtok(buf, delims);
+
+ while (token) {
+ char mtdname[16];
+ int mtdnum, mtdsize, mtderasesize;
+
+ res = sscanf(token, "mtd%d: %x %x %15s",
+ &mtdnum, &mtdsize, &mtderasesize, mtdname);
+
+ if (res == 4 && !strcmp(mtdname, findme))
+ return mtdnum;
+
+ token = strtok(NULL, delims);
+ }
+ return -1;
+}
+
+/* Init mounts /system as read only, remount to enable writes. */
+static int remount_system()
+{
+ int num;
+ char source[64];
+ if (system_ro == 0) {
+ return 0;
+ }
+ if ((num = find_mount("\"system\"")) < 0)
+ return -1;
+
+ snprintf(source, sizeof source, "/dev/block/mtdblock%d", num);
+ system_ro = mount(source, "/system", "yaffs2", MS_REMOUNT, NULL);
+ return system_ro;
+}
+
+static void write_string(int fd, const char* str)
+{
+ writex(fd, str, strlen(str));
+}
+
+void remount_service(int fd, void *cookie)
+{
+ int ret = remount_system();
+
+ if (!ret)
+ write_string(fd, "remount succeeded\n");
+ else {
+ char buffer[200];
+ snprintf(buffer, sizeof(buffer), "remount failed: %s\n", strerror(errno));
+ write_string(fd, buffer);
+ }
+
+ adb_close(fd);
+}
+