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global paging_init
align 4096
page_dir:
times 4096 db 0
align 4096
page_tables:
; two page tables
times 4096 db 0
times 4096 db 0
.end:
; here, we initialize paging. since the IDT
; has yet to be populated, we must take extra
; care as we can't afford to trigger a page
; fault.
paging_init:
push ebp
mov ebp, esp
push ebx
; populate the page directory
mov eax, page_tables
or eax, 0x007
mov [page_dir], eax
mov eax, (page_tables+4096)
or eax, 0x007
mov [page_dir+4], eax
; populate the page tables
mov ebx, page_tables
mov ecx, ((page_tables.end-page_tables)/4)
mov edx, 0
.loop:
mov eax, edx
or eax, 0x003
cmp edx, 0x100000
jb .skip
or eax, 0x004
.skip:
mov [ebx], eax
dec ecx
jz .end
add ebx, 4
add edx, 4096
jmp .loop
.end:
; load the page directory and enable paging
mov eax, page_dir
mov cr3, eax
mov eax, cr0
or eax, 0x80000000
mov cr0, eax
pop ebx
pop ebp
ret
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