购置回来的开发板如果想知道U盘或者SD卡能不能正常使用,对于支持安卓系统的开发板来说,直接插入是否正常打开存储设备就知道了;但是对于Linux开发板来说就没有那么直观了,那需要怎么检测存储设备是否能正常使用呢?
天嵌科技i.MX6UL工业级开发板配有4路Usb Host(2路双层USB接口,USB2/USB4与扩展接口/4PIN排针复用,可通过电阻选择,默认使用双层USB接口)和1路Usb OTG;由于系统使用的是ubi文件系统。所以在对文件系统进行写操作后,如果要断电、复位、重启等,请先执行sync,否则有可能写入的数据丢失。
1、SD卡
接上SD卡,系统会类似的打印以下信息:
# mmc0: host does not support reading read-only switch, assuming write-enable mmc0: new high speed SDHC card at address 0001 mmcblk0: mmc0:0001 SD8GB 7.27 GiB mmcblk0: p1 p2 #生成2个节点mmcblk0p1 mmcblk0p2
可以通过mount查看卡的挂载目录。可以像正常文件系统一样操作卡内的文件。另外,在修改数据过后,拔出卡时请先执行sync,否则会有低概率等造成数据修改失败。以下是笔者使用SD启动卡进行测试的过程:
# # mmc0: host does not support reading read-only switch, assuming write-enable mmc0: new high speed SDHC card at address 0001 mmcblk0: mmc0:0001 SD8GB 7.27 GiB mmcblk0: p1 p2 EXT3-fs (mmcblk0p2): error: couldn't mount because of unsupported optional features (240) FAT-fs (mmcblk0p1): Volume was not properly unmounted. Some data may be corrupt. Please run fsck. EXT2-fs (mmcblk0p2): error: couldn't mount because of unsupported optional features (244) EXT4-fs (mmcblk0p2): recovery complete EXT4-fs (mmcblk0p2): mounted filesystem with ordered data mode. Opts: (null) # mount ubi0:rootfs on / type ubifs (rw,relatime) devtmpfs on /dev type devtmpfs (rw,relatime,size=89476k,nr_inodes=22369,mode=755) proc on /proc type proc (rw,relatime) devpts on /dev/pts type devpts (rw,relatime,gid=5,mode=620) tmpfs on /dev/shm type tmpfs (rw,relatime,mode=777) tmpfs on /tmp type tmpfs (rw,relatime) tmpfs on /run type tmpfs (rw,nosuid,nodev,relatime,mode=755) sysfs on /sys type sysfs (rw,relatime) /dev/mmcblk0p2 on /run/media/mmcblk0p2 type ext4 (rw,relatime,data=ordered) /dev/mmcblk0p1 on /run/media/mmcblk0p1 type vfat (rw,relatime,gid=6,fmask=0007,dmask=0007,allow_utime=0020,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro) # # ls /run/media/mmcblk0p1 imx6ul-14x14-evk.dtb zImage # echo 1234 > /run/media/mmcblk0p1/tmp.txt # cat /run/media/mmcblk0p1/tmp.txt 1234 # sync # mmc0: card 0001 removed #
2、U盘
测试U盘的方法和SD卡的方法一样,只不过命令行中的mmcblk1p1换成sda1。
# usb 1-1.4: new high-speed USB device number 4 using ci_hdrc usb-storage 1-1.4:1.0: USB Mass Storage device detected scsi host1: usb-storage 1-1.4:1.0 scsi 1:0:0:0: Direct-Access SanDisk Ultra 1.00 PQ: 0 ANSI: 6 sd 1:0:0:0: [sda] 60062500 512-byte logical blocks: (30.7 GB/28.6 GiB) sd 1:0:0:0: [sda] Write Protect is off sd 1:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA sda: sda1 sd 1:0:0:0: [sda] Attached SCSI removable disk FAT-fs (sda1): Volume was not properly unmounted. Some data may be corrupt. Please run fsck. # mount ubi0:rootfs on / type ubifs (rw,relatime) devtmpfs on /dev type devtmpfs (rw,relatime,size=89476k,nr_inodes=22369,mode=755) proc on /proc type proc (rw,relatime) devpts on /dev/pts type devpts (rw,relatime,gid=5,mode=620) tmpfs on /dev/shm type tmpfs (rw,relatime,mode=777) tmpfs on /tmp type tmpfs (rw,relatime) tmpfs on /run type tmpfs (rw,nosuid,nodev,relatime,mode=755) sysfs on /sys type sysfs (rw,relatime) /dev/sda1 on /run/media/sda1 type fuseblk (rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096) # ls /run/media/sda1 1G_file SanDiskSecureAccess # usb 1-1.4: USB disconnect, device number 4
天嵌i.MX6UL工控板,拥有丰富的Usb接口,可满足客户产品各种要求。上文介绍的测试方法您掌握了没有?如有不明白之处请联系天嵌科技技术支持