[U-Boot] [PATCH v3 4/7] armv8: ls1043ardb: Use static DDR setting for SPL boot

[Łukasz Majewski]

Hi York,

> On 09/29/2017 12:44 AM, Łukasz Majewski wrote:
>> Hi York,
>>
>>> This board has soldered DDR chips. To reduce the SPL image size,
>>> use static DDR setting instead of dynamic DDR driver.
>>
>> I'm just wondering - since your board supports FIT in SPL, maybe it
>> would be good to have a binary blob with DDR RAM settings embedded into it?
>>
>> Then you would be able to provide "hardcoded" SDRAM setup via it?
>> In this way it could be easily replaceable?
>>
> 
> Lukasz,
> 
> It sounds reasonable but doesn't work for our platforms. The limitation
> is the static RAM. In order to load anything, we need to have some
> memory. Lacking of memory is the exact reason I have to use static DDR
> setting. I have to make room for other drivers in SPL.

I rather thought about:

Creating FIT image with firmware property, in which you will have 1:1 
binary image for DDR controller registers (e.g. 256B).

Then you could store this image to non-volatile memory and read it from 
SPL (just copy values to registers).

In that way you would be able to switch different configurations for 
different memories (DDR2/DDR3/, 1066, 1333 MHz) without the need to 
replace u-boot/SPL.

> 
> York
> 


-- 
Best regards,

Lukasz Majewski

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