TS-7180 EMMC

This board includes a Micron eMMC module. Our off-the-shelf builds are 4GiB, but up to 64GiB are available for larger builds. The eMMC flash appears to Linux as an SD card at /dev/mmcblk1. Our default programming will include one partition programmed with our Debian image.

eMMC also provides ways to estimate the wear on the module. First, determine your eMMC chipset revision:

root@tsimx6:~# mmc extcsd read /dev/mmcblk1 | grep "CSD rev"
[64446.059203]  mmcblk1: p1
  Extended CSD rev 1.7 (MMC 5.0)

or

root@tsimx6:~# mmc extcsd read /dev/mmcblk1 | grep "CSD rev"
[64446.059203]  mmcblk1: p1
  Extended CSD rev 1.5 (MMC 4.41)

In eMMC revision 5.0 and above, part of the specification includes a way to estimate lifetime of the chipset. For example:

root@tsimx6:~# mmc extcsd read /dev/mmcblk1 | grep -e EXT_CSD_DEVICE_LIFE_TIME -e PRE_EOL
[64618.159298]  mmcblk1: p1
eMMC Life Time Estimation A [EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_A]: 0x01
eMMC Life Time Estimation B [EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_B]: 0x01
eMMC Pre EOL information [EXT_CSD_PRE_EOL_INFO]: 0x01

If you have reconfigured your device as SLC, use TYP_A. If you are using the default MLC setting, use TYP_B. These LIFE_TIME_EST values indicate in 10s of percent how much of the reserve blocks are still available. The 0x1 value indicates < 10%. 0x7 would indicate < 70%.

EXT_CSD_PRE_EOL_INFO can also be used as an early warning indicator.

EXT_CSD_PRE_EOL_INFO values

Value	Description
0x1	Normal (< 80% blocks used)
0x2	Warning (> 80% blocks used)
0x3	Urgent (>90% blocks used)

If this is below 5.0, you must use a vendor specific utility. Micron eMMC uses the emmcparm utility. Refer to Micron's TN-FC-25 for the emmcparm utility and related documentation.