How FreeBSD manage more than 4GB on 32 bits architecture

[Arthur Chance]

On 09/04/2015 11:00, Pierre-Yves Péneau wrote:
>
> On 04/09/2015 11:49 AM, Ralf Mardorf wrote:
>> On Thu, 9 Apr 2015 11:49:41 +0200, Eduardo Morras wrote:
>>> You are looking for PAE.
>>
>> Hi,
>>
>> PAE does not support up to 8TB as the OP mentions. PAE is limited
>> to 64 GiB.
>>
>>
>
> Sorry, I forgot something important. My physical memory is 1TB, and as
> Ralf said, PAE is limited to 64GB (36 bits). I'm looking for a 40 bits
> support (at least).

I've just realised the original post said

 > According to the architecture handbook(*), "FreeBSD could
 > theoretically handle memory configurations up to 8TB on a 32 bit
 > platform."

Having followed the link, I find that's a partial quote, and the full 
one was

"In fact, if the mmu were capable of it, FreeBSD could theoretically 
handle memory configurations up to 8TB on a 32 bit platform. However, 
since most 32 bit platforms are only capable of mapping 4GB of ram, this 
is a moot point."

I.e. it was talking about the software architecture of the kernel 
virtual memory manager on 32 bit processors, not the hardware.

-- 
Those who do not learn from computing history are doomed to
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