L-1017e.A3 i.MX 8M Plus BSP Manual
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attribute
. This is left to the chipmaker. For the Micron chips, the
enhanced attribute
increases the reliability but also
halves the capacity.
The following sequence shows how to enable the
enhanced attribute
.
First obtain the current size of the eMMC device with:
target$ parted -m /dev/mmcblk2 unit B print
You will receive:
BYT;
/dev/mmcblk2:63652757504B:sd/mmc:
512
:
512
:unknown:MMC S0J58X:;
As you can see this device has 3783262208 Byte = 3608.0 MiB.
To get the maximum size of the device after
pseudo-SLC
is enabled use:
target$ mmc extcsd read /dev/mmcblk2 | grep ENH_SIZE_MULT -A
1
which shows, for example:
Max Enhanced Area Size [MAX_ENH_SIZE_MULT]:
0x000764
i.e.
3719168
KiB
--
Enhanced User Data Area Size [ENH_SIZE_MULT]:
0x000000
i.e.
0
KiB
Here the maximum size is 3719168 KiB = 3632 MiB.
Now, you can set
enhanced attribute
for the whole device, e.g. 3719168 KiB, by typing:
target$ mmc enh_area set -y
0
3719168
/dev/mmcblk2
You will get:
Done setting ENH_USR area on /dev/mmcblk2
setting OTP PARTITION_SETTING_COMPLETED!
Setting OTP PARTITION_SETTING_COMPLETED on /dev/mmcblk2 SUCCESS
Device power cycle needed
for
settings to take effect.
Confirm that PARTITION_SETTING_COMPLETED bit is set using
'extcsd read'
after power
cycle
Warning
When enabling the
enhanced attribute
on the device, all data will be lost.
