Intel architecture ia-32 Manuale Utente

4-42 Vol. 3A

tures. Execute-disable bit protection can be activated using the execute-disable bit at any level
of the paging structure, irrespective of the corresponding entry in other levels. When execute-
disable-bit protection is not activated, the page can be used as code or data.

In legacy PAE-enabled mode, Table 4-7 and Table 4-8 show the effect of setting the execute-
disable bit for code and data pages.
 

PML4

PDP

PDE

PTE

Bit 63 = 1

*

*

*

Data

*

Bit  63  =  1 

*

*

Data

*

*

Bit 63 = 1

*

Data

*

*

*

Bit 63 = 1

Data

Bit 63 = 0

Bit 63 = 0

Bit 63 = 0

Bit 63 = 0

Data/Code

NOTE:
* Value not checked.

PDE

PTE

Bit 63 = 1

*

Data

*

Bit 63 = 1

Data

Bit 63 = 0

Bit 63 = 0

Data/Code

NOTE:
* Value not checked.

PDE

Bit 63 = 1

Data

Bit 63 = 0

Data/Code