[U-Boot-Users] I2C or DIMM?

[Madhu Saravana Sibi Govindan]

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_MYDRAM:
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,
G.Sibi