Intel IA-32 - Manual (Page 118)

3-38 Vol. 3A
PROTECTED-MODE MEMORY MANAGEMENT
Figure 3-23 shows the format for the page-directory entries when 4-MByte pages and 36-bit
physical addresses are being used. Section 3.7.6, “Page-Directory and Page-Table Entries”
describes the functions of the flags and fields in bits 0 through 11.
Figure 3-22. Linear Address Translation (4-MByte Pages)
Figure 3-23. Format of Page-Directory Entries for 4-MByte Pages and
36-Bit Physical Addresses
0
Directory Offset
Page Directory
Directory Entry
CR3 (PDBR)
4-MByte Page
Physical Address
31 21 22
Linear Address
1024 PDE = 1024 Pages
10
22
32*
*32 bits aligned onto a 4-KByte boundary.
14
31
Available for system programmer’s use
Global page
Page size (must be set to 1)
Dirty
12 11 9 8 7 6 5 4 3 2 1 0
P
S
P
C A D
Accessed
Cache disabled
Write-through
User/Supervisor
Read/Write
Present
D
P
P
W
T
U
/
S
R
/
W
G Avail.
Page Base Address
Page-Directory Entry (4-MByte Page)
22 21
Reserved
13 16
(Bits 22 Through 31)
Page Base Address (Bits 32 Through 35)
Page Attribute Table Index
17
P
A
T