连接USB，打开USB存储设备，只显示手机内部的存贮（即EMMC的），外部SD卡电脑上显...

<StorageList xmlns:android="http://schemas.android.com/apk/res/android">
    <！-- removable is not set in nosdcard product -->
    <storage android:mountPoint="/mnt/sdcard"
                     android:storageDescription="@string/storage_phone"
                         android:allowMassStorage="true"
                     android:primary="true" />
                     
    <storage android:mountPoint="/mnt/sdcard2"
                     android:storageDescription="@string/storage_sd_card"
                     android:removable="true"
                         android:allowMassStorage="true"
                     android:primary="false" />
</StorageList>

请大侠帮忙看看！

system.prop
# USB Config Type
ro.sys.usb.storage.type=mtp,mass_storage
vold.fstab.nand
#dev_mount sdcard /mnt/sdcard auto /devices/platform/goldfish_mmc.0 /devices/platform/mtk-sd.1/mmc_host
dev_mount sdcard /mnt/sdcard emmc@fat /devices/platform/goldfish_mmc.0 /devices/platform/mtk-sd.0/mmc_host
dev_mount sdcard /mnt/sdcard/sdcard2 auto /devices/platform/goldfish_mmc.1 /devices/platform/mtk-sd.1/mmc_host
storage_list.xml
<StorageList xmlns:android="http://schemas.android.com/apk/res/android">
    <！-- removable is not set in nosdcard product -->
    <storage android:mountPoint="/mnt/sdcard"
                     android:storageDescription="@string/storage_phone"
                     android:allowMassStorage="true"
                     android:primary="true" />
                     
    <storage android:mountPoint="/mnt/sdcard2"
                     android:storageDescription="@string/storage_sd_card"
                     android:removable="true"
                     android:allowMassStorage="true"
                     android:primary="false" />

兄弟，你好，我的是EMMC，好象修改 vold.fstab.nand 没有作用