1*04a1c1a1SRobert Mustacchi.\" 2*04a1c1a1SRobert Mustacchi.\" This file and its contents are supplied under the terms of the 3*04a1c1a1SRobert Mustacchi.\" Common Development and Distribution License ("CDDL"), version 1.0. 4*04a1c1a1SRobert Mustacchi.\" You may only use this file in accordance with the terms of version 5*04a1c1a1SRobert Mustacchi.\" 1.0 of the CDDL. 6*04a1c1a1SRobert Mustacchi.\" 7*04a1c1a1SRobert Mustacchi.\" A full copy of the text of the CDDL should have accompanied this 8*04a1c1a1SRobert Mustacchi.\" source. A copy of the CDDL is also available via the Internet at 9*04a1c1a1SRobert Mustacchi.\" http://www.illumos.org/license/CDDL. 10*04a1c1a1SRobert Mustacchi.\" 11*04a1c1a1SRobert Mustacchi.\" 12*04a1c1a1SRobert Mustacchi.\" Copyright 2025 Oxide Computer Company 13*04a1c1a1SRobert Mustacchi.\" 14*04a1c1a1SRobert Mustacchi.Dd October 4, 2025 15*04a1c1a1SRobert Mustacchi.Dt EE100X 4D 16*04a1c1a1SRobert Mustacchi.Os 17*04a1c1a1SRobert Mustacchi.Sh NAME 18*04a1c1a1SRobert Mustacchi.Nm ee100x 19*04a1c1a1SRobert Mustacchi.Nd DDR4 serial presence detect driver 20*04a1c1a1SRobert Mustacchi.Sh SYNOPSIS 21*04a1c1a1SRobert Mustacchi.Pa /dev/eeprom/ee100x/*/eeprom 22*04a1c1a1SRobert Mustacchi.Sh DESCRIPTION 23*04a1c1a1SRobert MustacchiThe 24*04a1c1a1SRobert Mustacchi.Nm 25*04a1c1a1SRobert Mustacchidriver supports the I2C EEPROMs found on DDR4 DIMMs. 26*04a1c1a1SRobert MustacchiThe driver provides read-only access to the SPD 27*04a1c1a1SRobert Mustacchi.Pq serial presence detect 28*04a1c1a1SRobert MustacchiEEPROM through a character device powered by the 29*04a1c1a1SRobert Mustacchi.Xr eedev 4D 30*04a1c1a1SRobert Mustacchidriver. 31*04a1c1a1SRobert MustacchiThese devices are generally found at 7-bit addresses between 0x50 and 32*04a1c1a1SRobert Mustacchi0x57. 33*04a1c1a1SRobert MustacchiThe lower three bits of the address are used to indicate which DIMM the 34*04a1c1a1SRobert Mustacchidevice is found on 35*04a1c1a1SRobert Mustacchi.Pq ranging from 0 to 7 . 36*04a1c1a1SRobert Mustacchi.Pp 37*04a1c1a1SRobert MustacchiThe SPD device contains 512 bytes of memory that are organized into two 38*04a1c1a1SRobert Mustacchipages of 256 bytes each. 39*04a1c1a1SRobert MustacchiDevices can be found under 40*04a1c1a1SRobert Mustacchi.Pa /dev/eeprom/ee100x . 41*04a1c1a1SRobert MustacchiContents of the SPD data can be decoded with 42*04a1c1a1SRobert Mustacchi.Xr libjedec 3LIB . 43*04a1c1a1SRobert Mustacchi.Sh FILES 44*04a1c1a1SRobert Mustacchi.Bl -tag -width Pa 45*04a1c1a1SRobert Mustacchi.It Pa /dev/eeprom/spd511x/*/eeprom 46*04a1c1a1SRobert MustacchiEEPROM character device file. 47*04a1c1a1SRobert Mustacchi.It Pa /kernel/drv/amd64/ee100x 48*04a1c1a1SRobert MustacchiDevice driver (x86) 49*04a1c1a1SRobert Mustacchi.El 50*04a1c1a1SRobert Mustacchi.Sh SEE ALSO 51*04a1c1a1SRobert Mustacchi.Xr libjedec 3LIB , 52*04a1c1a1SRobert Mustacchi.Xr eedev 4D , 53*04a1c1a1SRobert Mustacchi.Xr spd511x 4D , 54*04a1c1a1SRobert Mustacchi.Xr i2cadm 8 55*04a1c1a1SRobert Mustacchi.Rs 56*04a1c1a1SRobert Mustacchi.%Q JEDEC Solid State Technology Association 57*04a1c1a1SRobert Mustacchi.%T 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 58*04a1c1a1SRobert Mustacchi.%N JESD21-C Release 26 59*04a1c1a1SRobert Mustacchi.Re 60