TS-7180 FRAM
From embeddedTS Manuals
The Cypress FM25L16B provides 2 KB of non-volatile memory in a manner not unlike an SPI EEPROM. However, the nature of ferro-electric RAM (FRAM) means it is incredibly fast to write, and is specified with 100 trillion read/write cycles per each byte and a 150 year data retention at temperatures below 65 ℃.
The FRAM can be accessed as a flat file from Linux:
# xxd -a /sys/class/spi_master/spi2/spi2.2/eeprom | head
00000000: 0000 0000 0000 0000 0000 0000 0000 0000 ................
*
000007f0: 0000 0000 0000 0000 0000 0000 0000 0030 ...............0
#
If U-Boot's bootcount tracking environment variable is enabled, the last byte of FRAM is reserved for storing the boot count, and care should be taken to not overwrite it inadvertently. In U-Boot, the boot count can be accessed with the 'fram' command.