EE100X(4D) Devices EE100X(4D)

ee100xDDR4 serial presence detect driver

/dev/eeprom/ee100x/*/eeprom

The ee100x driver supports the I2C EEPROMs found on DDR4 DIMMs. The driver provides read-only access to the SPD (serial presence detect) EEPROM through a character device powered by the eedev(4D) driver. These devices are generally found at 7-bit addresses between 0x50 and 0x57. The lower three bits of the address are used to indicate which DIMM the device is found on (ranging from 0 to 7).

The SPD device contains 512 bytes of memory that are organized into two pages of 256 bytes each. Devices can be found under /dev/eeprom/ee100x. Contents of the SPD data can be decoded with libjedec(3LIB).

/dev/eeprom/spd511x/*/eeprom
EEPROM character device file.
/kernel/drv/amd64/ee100x
Device driver (x86)

libjedec(3LIB), eedev(4D), spd511x(4D), i2cadm(8)

Definitions of the EE1004-v 4 Kbit Serial Presence Detect (SPD) EEPROM and TSE2004av 4 Kbit SPD EEPROM with Temperature Sensor (TS) for Memory Module Applications, JESD21-C Release 26, JEDEC Solid State Technology Association.

October 4, 2025 OmniOS