Intel IA-32 Instrukcja Użytkownika Strona 103

  • Pobierz
  • Dodaj do moich podręczników
  • Drukuj
  • Strona
    / 636
  • Spis treści
  • BOOKMARKI
  • Oceniono. / 5. Na podstawie oceny klientów
Przeglądanie stron 102
Vol. 3A 3-23
PROTECTED-MODE MEMORY MANAGEMENT
3.7.1 Linear Address Translation (4-KByte Pages)
Figure 3-12 shows the page directory and page-table hierarchy when mapping linear addresses
to 4-KByte pages. The entries in the page directory point to page tables, and the entries in a page
table point to pages in physical memory. This paging method can be used to address up to 2
20
pages, which spans a linear address space of 2
32
bytes (4 GBytes).
Table 3-3. Page Sizes and Physical Address Sizes
PG Flag,
CR0
PAE Flag,
CR4
PSE Flag,
CR4
PS Flag,
PDE
PSE-36 CPUID
Feature Flag Page Size
Physical Address
Size
0 X X X X Paging Disabled
1 0 0 X X 4 KBytes 32 Bits
1 0 1 0 X 4 KBytes 32 Bits
1 0 1 1 0 4 MBytes 32 Bits
1 0 1 1 1 4 MBytes 36 Bits
1 1 X 0 X 4 KBytes 36 Bits
1 1 X 1 X 2 MBytes 36 Bits
Figure 3-12. Linear Address Translation (4-KByte Pages)
0
Directory
Table
Offset
Page Directory
Directory Entry
CR3 (PDBR)
Page Table
Page-Table Entry
4-KByte Page
Physical Address
31 21 111222
Linear Address
1024 PDE 1024 PTE = 2
20
Pages
32*
10
12
10
*32 bits aligned onto a 4-KByte boundary.
20
Przeglądanie stron 102
1 2 ... 98 99 100 101 102 103 104 105 106 107 108 ... 635 636

Komentarze do niniejszej Instrukcji

Brak uwag