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

MJ embd
2013-09-17T17:07:09Z

yes, I am using uboot for arndale board.
The code is written by samsung only and it is not static.

The best option would be to have an eth / serial driver kind of arch
which all soc vendors can share. But ddr is scattered, in absence of
that, your point seems valid for fsl specific.

-mj

On 9/17/13, York Sun <yorksun@freescale.com> wrote:
> 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@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
>>>
>>> _______________________________________________
>>> U-Boot mailing list
>>> U-Boot at lists.denx.de
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>>>
>>
>>
>
>
>

--
-mj