[ros-dev] 2GB Boundary

[Alex Ionescu]

Eric Kohl wrote:

>"Aliberti Emanuele" <ea at iol.it> wrote:
>
>  
>
>>>I agree! But I think we should move the ntoskrnl base address to
>>>      
>>>
>0x80100000
>  
>
>>>and map the first MB of physical memory to 0x80000000 - 0x800FFFFF in
>>>      
>>>
>order
>  
>
>>>to simplify BIOS calls.
>>>
>>>
>>>
>>>      
>>>
>>Does that conflict with the statement I read in some books about
>>completely skipping the low 64k physical address range for ease of
>>detecting NULL pointers?
>>    
>>
>
>This is not 100% correct. The lowest 64k of the process _virtual_ address
>space is is reserved and protected in order to detect NULL pointer access.
>
>Regards,
>Eric
>  
>
Getting back to what Eric suggested, we should also perhaps do like NT 
does, and cache the GDT and IDT somewhere between 0x80000000 and the 
kernel base as well.

Best regards,
Alex Ionescu