[U-Boot] U-boot PPC405EX with DDR2 DIMM

[Steve Miller]

Hello,

I have inherited a design using the PPC405EX that was based on the
Kilauea reference design.   One of the changes was Kilauea uses on-board
DDR2 DRAM ICs and this design uses DDR2 DIMMs.   The u-boot is working,
except only 256MB of RAM is available instead of the 1GIG that the
module supports.   This working 256MB matches the memory that the
Kilauea had.  In looking into this, the CONFIG_SPD_EEPROM was undefined,
as that was what was appropriate for the Kilauea.   I defined this but
got lots of compiler errors.  So I did the following:

 

1.        Updated the eldk to 5.4

2.       Downloaded the latest u-boot source code I could find.
(Version 2013)

 

I still get compiler errors.  The first error is in 40x_spd_sdram.c    I
do not believe it should be attempting to compile this as it appears to
be SPD setting for SDRAM modules and not DDR2 modules.  I added another
check to line 50 of 40x_spd_sdram.c to skip that file if it is a 405EX.
This of course, eliminated those compiler errors.

 

Next place is has trouble is 44x_spd_ddr2.c   In line 460 it cannot find
SDR0_SRST0_DMC for example.  Another example is line 821, it cannot find
SDR0_DDR0.   In searching the PPC405EX datasheet, I do not find that
these registers exist in this part.    I believe it is supposed to
compile this file, as the file has specific references to the 405EX.
However, I do not know what I am missing to get this to compile for that
processor. 

 

Questions:

 

1.        Has anyone compiled u-boot for the 405EX using a DIMM, aka an
SPD defined RAM?

2.       Is there something obvious that I need to place in the config
to get this to work?   I compared this config to another product that
uses a 460SX.  I did not see anything special that the 460SX was
configuring to make the system work with the SPD of the DIMM.  

 

Thanks for any pointers.

 

---- Steve