[U-Boot] 36-bit u-boot

[Andre Schwarz]

Leif,

> I have managed to flashed a 36-bits u-boot to my p4080 board.
>
> I have put in two 4Gb dimm into the board but it doesn't work.
>
> I got the following from u-boot.
>
>    
[snip]
> DRAM:  Initializing....
>
> Error: DDR_SDRAM_CFG[RD_EN] and DDR_SDRAM_CFG[2T_EN]  should not be set at the same time.
>    

"RD_EN" means "registered DIMM enable" which is read from PROM on memory 
module.

Looks like you have CONFIG_DDR_2T_TIMING defined in your board header 
... which is mutually exclusive with registered DIMM usage.
2T timing is only useful if you have AC timing violations regarding 
setup/hold on Addr/Cmd Bus.

> Error: DDR_SDRAM_CFG[RD_EN] and DDR_SDRAM_CFG[2T_EN]  should not be set at the same time.
>
> 6144M left unmapped
>
>      DDR:  8 GB
>
> """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
>
> It seams that it is something wrong with the DDR initiation.
>    

no.

You can either use unregistered DIMM modules or simply undefine 
CONFIG_DDR_2T_TIMING.


Cheers,
André

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