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Index > OS Construction > 4GB memory limit

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CandyMan



Joined: 04 Sep 2009
Posts: 322
Location: film "CandyMan" directed through Bernard Rose OR Candy Shop
CandyMan
Whether it is possible to gain access to the memory above 4GB on 32-bit operating systems?
Any examples...
Post 12 Dec 2011, 17:01
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ManOfSteel



Joined: 02 Feb 2005
Posts: 1155
ManOfSteel
Yes, PAE.
Post 12 Dec 2011, 17:05
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egos



Joined: 10 Feb 2009
Posts: 144
egos
For 4 mb pages you can use PSE-36 mode if it's supported.
It is possible to use long mode paging structures for 32-bit OS.
Post 14 Dec 2011, 09:15
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smiddy



Joined: 31 Oct 2004
Posts: 559
smiddy
If you go to long mode, wouldn't you want to stay or run from long mode?

I will be struggling with this in the coming months once I get my OS to boot off of CD. It is 32-bit at the moment, but I want to go to long mode and from what I've read I am stuck using paging, when my OS is flat memory based, can I set one "large" page? I assume there isn't enough bits in the table (sorry, my vernacular is likely wrong, I'm relearning this since being away for 6 ish years), that I can't directly address say 40 bits of memory, perhaps? Or can I? References are always welcome (even if they cost money, I'll go buy them).
Post 14 Dec 2011, 23:39
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revolution
When all else fails, read the source


Joined: 24 Aug 2004
Posts: 17719
Location: In your JS exploiting you and your system
revolution
smiddy wrote:
I assume there isn't enough bits in the table (sorry, my vernacular is likely wrong, I'm relearning this since being away for 6 ish years), that I can't directly address say 40 bits of memory, perhaps? Or can I? References are always welcome (even if they cost money, I'll go buy them).
No need to assume anything. Paging is fully described in the Intel/AMD manuals. And they are free.
Post 15 Dec 2011, 00:01
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smiddy



Joined: 31 Oct 2004
Posts: 559
smiddy
Thanks, when I get to that point. I am debugging my boot loader from CD. Within the next month or so...
Post 15 Dec 2011, 01:44
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