IMX6新增识别usb设备

fstab.freescale文件修改如下：

# Android fstab file.
#                                                           <type>    and options>                       
# The filesystem that contains the filesystem checker binary (typically /system) cannot
# specify MF_CHECK, and must come before any filesystems that do specify MF_CHECK

/devices/soc0/soc.1/2100000.aips-bus/2190000.usdhc/mmc_host /mnt/media_rw/extsd vfat defaults voldmanaged=extsd:auto
/devices/soc0/soc.1/2100000.aips-bus/2184000.usb/ci_hdrc.0  /mnt/media_rw/udisk vfat defaults voldmanaged=udisk:auto
/devices/soc0/soc.1/2100000.aips-bus/2184200.usb/ci_hdrc.1  /mnt/media_rw/udisk2 vfat defaults voldmanaged=udisk2:auto
/dev/block/mmcblk2p5    /system      ext4    ro                                                                               wait
/dev/block/mmcblk2p4    /data        ext4    nosuid,nodev,nodiratime,noatime,nomblk_io_submit,noauto_da_alloc,errors=panic    wait,encryptable=footer
/dev/block/mmcblk2p6    /cache       ext4    nosuid,nodev,nomblk_io_submit                                                    wait
/dev/block/mmcblk2p7    /device      ext4    ro,nosuid,nodev                                                                  wait
/dev/block/mmcblk2p1    /boot        emmc    defaults                                                                         defaults
/dev/block/mmcblk2p2    /recovery    emmc    defaults                                                                         defaults
/dev/block/mmcblk2p8    /misc        emmc    defaults                                                                         defaults
/dev/block/mmcblk2p10   /backconf    ext4    rw                                                                               wait
/dev/block/mmcblk2p11   /navi        ext4    rw  

init.rc新增如下：

    mkdir /mnt/media_rw/edisk 0755 system system
    symlink /mnt/media_rw/edisk /storage/edisk
    mkdir /mnt/media_rw/udisk 0755 system system
    symlink /mnt/media_rw/udisk /storage/udisk
    symlink /storage/udisk /mnt/udisk

    mkdir /mnt/media_rw/udisk2 0755 system system
    symlink /mnt/media_rw/udisk2 /storage/udisk2
    symlink /storage/udisk2 /mnt/udisk2

frameworks/base/core/res/res/xml/storage_list.xml,驱动新增udisk2后，framework层修改如下：

"1.0" encoding="utf-8"?>
--
**
** Copyright 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.
*/
-->

-- The  element should contain one or more  elements.
     Exactly one of these should have the attribute primary="true".
     This storage will be the primary external storage and should have path="/mnt/sdcard".
     Each storage should have both a path and description attribute set.
     The following boolean attributes are optional:

        primary:    this storage is the primary external storage
        removable:  this is removable storage (for example, a real SD card)
        emulated:   the storage is emulated via the FUSE sdcard daemon
        mtp-reserve: number of megabytes of storage MTP should reserve for free storage
                     (used for emulated storage that is shared with system's data partition)

      A storage should not have both emulated and removable set to true
-->

"http://schemas.android.com/apk/res/android">
    "@string/storage_internal"
             android:primary="true"
             android:emulated="true"
             android:mtpReserve="100" />
    "/storage/extsd"
             android:storageDescription="@string/storage_sd_card"
             android:primary="false"
             android:removable="true" />
    "/storage/udisk"
             android:storageDescription="@string/storage_usb"
             android:primary="false"
             android:removable="true" />
    "/storage/udisk2"
         android:storageDescription="@string/storage_usb"
         android:primary="false"
         android:removable="true" />