vold: Add support for xwarp

Signed-off-by: San Mehat <san@google.com>
diff --git a/Xwarp.cpp b/Xwarp.cpp
new file mode 100644
index 0000000..1435a53
--- /dev/null
+++ b/Xwarp.cpp
@@ -0,0 +1,83 @@
+/*
+ * 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 <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#define LOG_TAG "Vold"
+
+#include <cutils/log.h>
+
+#include "Xwarp.h"
+const char *Xwarp::XWARP_BACKINGFILE = "/mnt/secure/asec/xwarp.img";
+const char *Xwarp::XWARP_CFG = "/sys/fs/yaffs/mtd3/xwarp-backing-store";
+const char *Xwarp::XWARP_READY = "/sys/fs/yaffs/mtd3/xwarp-ready";
+const char *Xwarp::XWARP_MIRROR_STATUS = "/sys/fs/yaffs/mtd3/xwarp-mirror";
+
+int Xwarp::enable() {
+    return doEnableDisable(true);
+}
+
+int Xwarp::disable() {
+    return doEnableDisable(false);
+}
+
+int Xwarp::status(bool *ready, unsigned *mirrorPos, unsigned *maxSize) {
+    FILE *fp;
+
+    *ready = false;
+    *mirrorPos = 0;
+    *maxSize = 0;
+    if (!(fp = fopen(XWARP_READY, "r"))) {
+        return -1;
+    }
+
+    fscanf(fp, "%d", (int *) ready);
+    fclose(fp);
+
+    if (!(fp = fopen(XWARP_MIRROR_STATUS, "r"))) {
+        return -1;
+    }
+
+    fscanf(fp, "%u %u", mirrorPos, maxSize);
+    fclose(fp);
+    return 0;
+}
+
+int Xwarp::doEnableDisable(bool enable) {
+    const char *tmp;
+    int fd = open(XWARP_CFG, O_WRONLY);
+
+    if (fd < 0) 
+        return -1;
+
+    tmp = (enable ? XWARP_BACKINGFILE : "");
+
+    if (write(fd, tmp, strlen(tmp)+1) < 0) {
+        LOGE("Failed to write xwarp cfg (%s)", strerror(errno));
+        close(fd);
+        return -1;
+    }
+
+    close(fd);
+    return 0;
+}