[U-Boot] How do ARM platform initialize DDR?

[York Sun]

Dear MJ,

Thanks for your reply.

I don't see the file in my copy. Probably it is not merged yet?
Anyway, you just confirmed what I found so far. Do you use static
setting in dmc_init_ddr3.c? I mean does it adapt to different DDR speeds
and modules (if applicable)?

In my mind, I am thinking to restructure arch/powerpc/cpu/mpc8xxx/ddr/
to driver/ddr/fsl/ so the same driver can be shared as far as the DDR IP
is the same (or similar).

York


On 09/17/2013 09:34 AM, MJ embd wrote:
> Hi York,
> 
> There is no generic driver. AFAIK. Having worked on both mpc85xx and ARM
> 
> I can tell you about samsung 5250. There are 2 uboots (one spl and other main).
> In case of sd/mmc boot the internal rom copies the spl uboot to iRAM
> and the spl boot loader initialises the DDR3.
> 
> you can check for board/samsung/smdk5250/dmc_init_ddr3.c
> 
> -Regards
> mj
> 
> On 9/17/13, York Sun <yorksun at freescale.com> wrote:
>> Albert,
>>
>> Pardon me if this is a dumb question. I have been working on powerpc
>> platforms in the past. Now we (the developers I work with) are exploring
>> ARM cores. I am searching how memory is initialized and found different
>> solutions. Some platforms have memory ready before u-boot even starts,
>> some simply write to a set of registers. I understand many platforms
>> don't share the IP of DDR controller. I am wondering if there is generic
>> DDR driver used by many ARM platforms, like the one we have for
>> powerpc/mpc85xx SoCs.
>>
>> Regards,
>>
>> York
>>
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> 
>