IBASE Technology RP-103-SMC User Manual page 92

5. SD Card Test
When SMARC is booted from eMMC, SD card is "/dev/mmcblk1" and able to see by
"ls /dev/mmcblk1*" command:
/dev/mmcblk1 /dev/mmcblk1p2 /dev/mmcblk1p4
/dev/mmcblk1p5 /dev/mmcblk1p6
When SMARC is booted from SD card, replace test pattern "/dev/mmcblk1" to
"/dev/mmcblk0".
Note: This operation may damage the data stored the SD card. Before starting the
test, make sure there is no critical data in the eMMC flash being used.
Read, write, and check
•
SD_DIR="/run/media/mmcblk1"
#create data file
dd if=/dev/urandom of=/var/data1 bs=1024k count=100
#write data to SD card
dd if=/var/data1 of=$ SD_DIR/data2 bs=1024k count=100
#read data2, and compare with data1
cmp $SD_DIR/data2 /var/data1
SD card speed test
•
SD_DIR="/run/media/mmcblk1"
# SD write speed
dd if=/dev/zero of=$SD_DIR/test bs=1M count=1000
oflag=nocache
# SD read speed
dd if=$SD_DIR/test of=/dev/null bs=1M oflag=nocache
84 RP-103-SMC User Manual