Mmc (Emmc/Sd) Test; Read/Write Operations; Write Protect - Advantech RSB-4760 User Manual

ATTR{hctosys}=="0"
ATTR{max_user_freq}=="64"
ATTR{name}=="rtc‐s35390a"
ATTR{wakealarm}==""
2. Add udev rule
$ vi /etc/udev/rules.d/99-rtc1.rules
KERNEL=="rtc1", SUBSYSTEM=="rtc", DRIVER=="", ATTR{name}==" ",
rtc‐s35390a
SYMLINK="rtc", MODE="0666"
3. Run the rule
$ udevadm test /sys/class/rtc/rtc1
...
creating link '/dev/rtc' to '/dev/rtc1'
atomically replace '/dev/rtc'
...
4. Confirm
$ ls -al /dev/rtc*
lrwxrwxrwx 1 root root 4 May 19 2017 /dev/rtc ‐> rtc1
crw‐‐‐‐‐‐‐ 1 root root 254, 0 May 19 2017 /dev/rtc0
crw‐‐‐‐‐‐‐ 1 root root 254, 1 Jan 1 02:10 /dev/rtc1

3.1.8. MMC (eMMC/SD) Test

3.1.8.1. Read/Write Operations

It's simple to verify read/write operations for MMC devices.
You can use many tools to do this, e.g. dd, vi, cp, etc.
eMMC: /dev/mmcblk0
SD: /dev/mmcblk1

3.1.8.2. Write Protect

We support write protect feature for SD card.
Once a SD card with write proctection is inserted, you can see "RO" message in kernel log.
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