Phytec i.MX 93 - Page 56

i.MX 93 BSP Manual PD24.1.1 Documentation Rev.: imx8mp-pd22.1.2-51-ga548be7d
• Resize the lesystem to a new partition size:
target:~$ resize2fs /dev/mmcblk0p2
resize2fs 1.46.1 (9-Feb-2021)
Filesystem at /dev/mmcblk0p2 is mounted on /; on-line resizing required
[ 131.609512] EXT4-fs (mmcblk0p2): resizing filesystem
from 454136 to 7367680 blocks
old_desc_blocks = 4, new_desc_blocks = 57
[ 131.970278] EXT4-fs (mmcblk0p2): resized filesystem to 7367680
The filesystem on /dev/mmcblk0p2 is now 7367680 (1k) blocks long
Increasing the lesystem size can be done while it is mounted. But you can also boot the board from an SD
card and then resize the le system on the eMMC partition while it is not mounted.
7.4.5 Enable pseudo-SLC Mode
eMMC devices use MLC or TLC (https://en.wikipedia.org/wiki/Multi-level_cell) to store the data. Com-
pared with SLC used in NAND Flash, MLC or TLC have lower reliability and a higher error rate at lower
costs.
If you prefer reliability over storage capacity, you can enable the pseudo-SLC mode or SLC mode. The
method used here employs the enhanced attribute, described in the JEDEC standard, which can be set for
continuous regions of the device. The JEDEC standard does not specify the implementation details and the
guarantees of the enhanced attribute. This is left to the chipmaker. For the Micron chips, the enhanced
attribute increases the reliability but also halves the capacity.
Warning
When enabling the enhanced attribute on the device, all data will be lost.
The following sequence shows how to enable the enhanced attribute.
• First obtain the current size of the eMMC device with:
target:~$ parted -m /dev/mmcblk0 unit B print
You will receive:
BYT;
/dev/mmcblk0:63652757504B:sd/mmc:512:512:unknown:MMC S0J58X:;
As you can see this device has 63652757504 Byte = 60704 MiB.
• To get the maximum size of the device after pseudo-SLC is enabled use:
target:~$ mmc extcsd read /dev/mmcblk0 | 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.
Accessing Peripherals 52