Write assembly variant to EEPROM

It would be convenient to have assembly variant written to EEPROM so that it can be read by MMC. Contents would be written by the manufacturer according to the requested variant configuration.

Estimation of required EEPROM size will have to be made as soon as all variants are defined.

changed title from Write mounting variant to EEPROM to Write assembly variant to EEPROM

changed the description

This is indeed important, and is already dealt with by the openMMC code.

Also, different assembly variants define different FRUs, and the MMC must be aware of that to function properly. From the MMC point of view, an assembly variant is just another version of the board, which can be represented by a letter (we use 3.1T for our timing version of AFC at LNLS) or the usual dot representation (eg 3.1.1).

@henrique.silva is much better positioned to explain that than me.

Such EEPROM could also hold clocking mux configuration.

From my experience of working for AFC manufacturer, letters might not be enough to express the rich variety of existing AFC variants ;-). Additionally, I believe having direct access to the variant configuration that is stuck to the board instead of the firmware could be somehow handy.

We're going for an external EEPROM that is write-protected by default.

Add it in parallel with IC27, something like 64kb. Beware of I2C addressing.

Added AT24C64D-SSHM-T 64K (8192 x 8) EEPROM. Connected Write Protection to free MMC pin.

Updated I2C address map:

The other solution would be to use a single EEPROM and put assembly variant and clock configuration as OEM record in FRU Info.

mentioned in commit c2b15c2f

@KMacias Am I right that currently FRU is embedded into MMC firmware? If so, it is not relevant place as rebuilding firmware will require information on assembly variant.

Solved in c2b15c2f.

closed

I checked with @henrique.silva , the FRU is already read from the EEPROM by OpenMMC, using the IPMI standard for FRU.