recovery中如何挂载sdcard

recovery中手机盘使用mnt/sdcard 或者使用storage/emulated/0/这些都不行。因为手机在recovery中的挂载点跟系统启动起来是不一样的。

1：可以查看fstab，查看手机挂载点。

2：如果在recovery中挂载不上sdcard，可以手动挂载一下，方法如下：

   ensure_path_mounted("/sdcard");

int ensure_path_mounted(const char* path) {
    // Mount at the default mount point.
    return ensure_path_mounted_at(path, nullptr);
}

int ensure_path_unmounted(const char* path) {
    Volume* v = volume_for_path(path);
    if (v == NULL) {
        LOGE("unknown volume for path [%s]\n", path);
        return -1;
    }
    if (strcmp(v->fs_type, "ramdisk") == 0) {
        // the ramdisk is always mounted; you can't unmount it.
        return -1;
    }

    int result;
    result = scan_mounted_volumes();
    if (result < 0) {
        LOGE("failed to scan mounted volumes\n");
        return -1;
    }

    const MountedVolume* mv =
        find_mounted_volume_by_mount_point(v->mount_point);
    if (mv == NULL) {
        // volume is already unmounted
        return 0;
    }

    return unmount_mounted_volume(mv);
}