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Re: Downloading and naming



On Sun, Jul 31, 2016, at 19:07, Pascal Hambourg wrote:
> Le 01/08/2016 à 00:00, Stephen Powell a écrit :
>> one's processor supports PAE, but the motherboard only supports a maximum of
>> 2 GiB of RAM, what does a PAE kernel buy one?  Nothing, as far as I can see.
> 
> PAE allows to use the NX/XD bit on CPU which support it to prevent 
> execution of data memory areas.

To the best of my knowledge, there are no 32-bit-only processors which
support the NX bit.  A 32-bit PAE-enabled kernel can only use NX if it
is running on a 64-bit-capable processor.  I should have explicitly stated
what was an implicit assumption, namely, that the processor is not
64-bit capable.  To give a specific example, my IBM ThinkPad X31 has
a Pentium M processor, which is PAE capable and 32 bit only, and the motherboard
only supports a maximum of 2 GiB of RAM.  I *can* run a PAE-enabled kernel
on it, but a PAE-enabled kernel uses more memory.  PAE allows more than 4 GiB
of memory to be accessed, but I don't have that much.  And the PAE kernel
can't exploit the NX bit, because the processor doesn't support it.
A PAE-enabled kernel actually *hurts* me in this case.  I'm better off running
a non-PAE kernel, even though the processor supports PAE. 

-- 
  .''`.     Stephen Powell    <zlinuxman@fastmail.com>
 : :'  :
 `. `'`
   `-


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