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Use 2MiB pages instead of one 1GiB page

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Philipp Oppermann
2015-10-29 17:41:05 +01:00
parent dfabc0ff32
commit 2a35ec19b6
1 changed files with 19 additions and 2 deletions
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21
src/arch/x86_64/boot.asm
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@@ -44,8 +44,23 @@ setup_page_tables:
or eax, 0b11 ; present + writable
mov [p4_table], eax
; map first P3 entry to a huge page that starts at address 0
mov dword [p3_table], 0b10000011 ; present + writable + huge
; map first P3 entry to P2 table
mov eax, p2_table
or eax, 0b11 ; present + writable
mov [p3_table], eax
; map each P2 entry to a huge 2MiB page
mov ecx, 0 ; counter variable
.map_p2_table:
; map ecx-th P2 entry to a huge page that starts at address (2MiB * ecx)
mov eax, 0x200000 ; 2MiB
imul eax, ecx ; start address of ecx-th page
or eax, 0b10000011 ; present + writable + huge
mov [p2_table + ecx * 8], eax ; map ecx-th entry
inc ecx ; increase counter
cmp ecx, 512 ; if counter == 512, the whole P2 table is mapped
jne .map_p2_table ; else map the next entry
ret
@@ -131,6 +146,8 @@ p4_table:
resb 4096
p3_table:
resb 4096
p2_table:
resb 4096
stack_bottom:
resb 64
stack_top: