[U-Boot] [PATCH 05/10] board: altera: Stratix10: Add board_get_usable_ram_top()

[Marek Vasut]

On 3/12/19 3:33 PM, Westergreen, Dalon wrote:
> On Tue, 2019-03-12 at 11:46 +0100, Marek Vasut wrote:
>> On 3/12/19 9:31 AM, Ley Foon Tan wrote:
>>> Add board_get_usable_ram_top() function. Limit maximum usable
>>> ram top to 2GB.
>>
>> Why ? There are ARM64 platforms which can access the entire DRAM range
>> just fine, what's the problem ?
>>
> 
> The issue is the gap in memory between 2GB and 4GB.  There is some trickery
> you can use to gain access to the memory in that range, but in general, you
> dont have access.  I believe just setting the banks up in the dts will
> resolve this.

E.g. the R8A779{5..9}* platforms also have gaps in memory and it all
works fine . So unless there's some other specialty, there should be no
problem.

-- 
Best regards,
Marek Vasut