[U-Boot-Users] I2C or DIMM?

Madhu Saravana Sibi Govindan ssshayagriva at gmail.com
Mon Jun 19 03:40:53 CEST 2006

Hello all,

I'm trying to debug u-boot on a custom board, which is similar to the
ebony board. I see the following output on the serial console:


U-Boot 1.1.4 (Jun 18 2006 - 20:35:07)

CPU:   AMCC PowerPC 440GP Rev. C at 300 MHz (PLB=100, OPB=50, EBC=50 MHz)
       Internal PCI arbiter disabled
       32 kB I-Cache 32 kB D-Cache
Board: Ebony - AMCC PPC440GP Evaluation Board
I2C:   ready
DRAM:  Calling spd_sdram
 Within the SPD SDRAM function
Trying a printf now
ERROR: Unsupported DIMM detected in slot 0.
Only DDR SDRAM DIMMs are supported.
Replace the DIMM module with a supported DIMM.

Read dimm_type = 255
### ERROR ### Please RESET the board ###


(I have put in some additional debug statements in the u-boot code)

It is not clear to me if the DIMM alone is the problem or if the I2C
controller was not initialized correctly somehow (and so we are seeing
a weird value from the EEPROM).  I'm going to try to put in a new DIMM
and then, try the whole exercise again, but is there a way to check if
the I2C controller is working fine?

I'm also going to read the other bytes from the EEPROM and see if they
make sense.

Thanks in advance,

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