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EE1004: Difference between revisions
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[https://www.jedec.org/category/keywords/ee1004-v EE1004-v] is a JEDEC standard for [[SPD]] published May 2022. It is used in DDR4+ DIMMs, and has its own kernel module, <tt>ee1004</tt>, superseding the <tt>at24</tt> module used for AT24C02 EEPROMs. These are 512-byte devices accessed through a single I2C address; | [https://www.jedec.org/category/keywords/ee1004-v EE1004-v] is a JEDEC standard for [[SPD]] published May 2022. It is used in DDR4+ DIMMs, and has its own kernel module, <tt>ee1004</tt>, superseding the <tt>at24</tt> module used for AT24C02 EEPROMs. These are 512-byte devices accessed through a single I2C address; SMBus controls whether the upper or lower page is accessed. | ||
==Binding EE1004== | ==Binding EE1004== | ||
Load the <tt>eeprom</tt> and <tt>ee1004</tt> modules (the former is still necessary for <tt>decode-dimms</tt> to function, but is deprecated). Determine which DIMMs are populated via addresses 0x50--0x57 on an | Load the <tt>eeprom</tt> and <tt>ee1004</tt> modules (the former is still necessary for <tt>decode-dimms</tt> to function, but is deprecated). Determine which DIMMs are populated via addresses 0x50--0x57 on an SMBus-type I2C connection. Here, buses 0 and 1 are SMBus (using the <tt>i2c-piix4</tt> module). | ||
<pre> | <pre> | ||
[schwarzgerat](0) $ i2cdetect -l | [schwarzgerat](0) $ i2cdetect -l | ||
Revision as of 20:16, 4 September 2022
EE1004-v is a JEDEC standard for SPD published May 2022. It is used in DDR4+ DIMMs, and has its own kernel module, ee1004, superseding the at24 module used for AT24C02 EEPROMs. These are 512-byte devices accessed through a single I2C address; SMBus controls whether the upper or lower page is accessed.
Binding EE1004
Load the eeprom and ee1004 modules (the former is still necessary for decode-dimms to function, but is deprecated). Determine which DIMMs are populated via addresses 0x50--0x57 on an SMBus-type I2C connection. Here, buses 0 and 1 are SMBus (using the i2c-piix4 module).
[schwarzgerat](0) $ i2cdetect -l i2c-0 smbus SMBus PIIX4 adapter port 0 at 0b00 SMBus adapter i2c-1 smbus SMBus PIIX4 adapter port 2 at 0b00 SMBus adapter ..... [schwarzgerat](0) $
Let's take a look across bus 0:
[schwarzgerat](0) $ i2cdetect -y 0
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: 08 09 -- -- 0c -- -- --
10: 10 11 -- 13 14 15 -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- 27 28 -- -- -- -- -- -- --
30: 30 31 -- -- 34 35 -- 37 -- -- 3a -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- 4a -- -- -- -- --
50: UU UU UU UU UU UU UU UU -- -- -- -- -- -- -- --
60: -- -- 62 63 64 -- -- -- 68 69 -- -- 6c -- -- --
70: 70 71 72 -- 74 -- 76 --
[schwarzgerat](0) $
Here, we see my 8 DIMMs populating addresses 0x50 through 0x57. We now must associate these addresses with ee1004:
[schwarzgerat](0) $ for i in `seq 0 7` ; do echo ee1004 0x5$i | sudo tee /sys/bus/i2c/devices/i2c-0/new_device ; done ee1004 0x50 ee1004 0x51 ee1004 0x52 ee1004 0x53 ee1004 0x54 ee1004 0x55 ee1004 0x56 ee1004 0x57 [schwarzgerat](1) $
At this point, decode-dimms ought be able to pull the EE1004 information. Try using decode-dimms --side-by-side for more compact presentation.
