/***********************************************************************
* I.MX6 32G SD卡测试
* 说明：
* 这是刘涛测试32G卡的情况。
*
* 2016-10-17 深圳 南山平山村 曾剑锋
**********************************************************************/ 一、参考文档：
[solved] couldn't mount because of unsupported optional
https://forums.gentoo.org/viewtopic-p-7259024.html 二、32G SD卡挂载情况测试：
. fat
ok
. ext2
ok
. ext3
root@freescale ~$ mount -t ext3 /dev/mmcblk1p1
root@freescale ~$ mount /dev/mmcblk1p1 /mnt/mount/
root@freescale ~$ mount -t ext3 /dev/mmcblk1p1 /mnt/mount/
EXT3-fs: barriers not enabled
kjournald starting. Commit interval seconds
EXT3-fs (mmcblk1p1): using internal journal
EXT3-fs (mmcblk1p1): mounted filesystem with writeback data mode
. ext4
root@freescale ~$ mount /dev/mmcblk1p1 /mnt/mount/
EXT3-fs (mmcblk1p1): error: couldn't mount because of unsupported optional features (240)
EXT2-fs (mmcblk1p1): error: couldn't mount because of unsupported optional features (240)
EXT4-fs (mmcblk1p1): mounted filesystem with ordered data mode. Opts: (null)