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Philipp Oppermann
2017-04-11 14:55:41 +02:00
parent b199b02578
commit 936e2073a9
1 changed files with 24 additions and 0 deletions
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24
src/arch/x86_64/boot.asm
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@@ -10,6 +10,7 @@ start:
call check_long_mode call check_long_mode
call set_up_page_tables call set_up_page_tables
call enable_paging
; print `OK` to screen ; print `OK` to screen
mov dword [0xb8000], 0x2f4b2f4f mov dword [0xb8000], 0x2f4b2f4f
@@ -103,6 +104,29 @@ set_up_page_tables:
ret ret
enable_paging:
; load P4 to cr3 register (cpu uses this to access the P4 table)
mov eax, p4_table
mov cr3, eax
; enable PAE-flag in cr4 (Physical Address Extension)
mov eax, cr4
or eax, 1 << 5
mov cr4, eax
; set the long mode bit in the EFER MSR (model specific register)
mov ecx, 0xC0000080
rdmsr
or eax, 1 << 8
wrmsr
; enable paging in the cr0 register
mov eax, cr0
or eax, 1 << 31
mov cr0, eax
ret
; Prints `ERR: ` and the given error code to screen and hangs. ; Prints `ERR: ` and the given error code to screen and hangs.
; parameter: error code (in ascii) in al ; parameter: error code (in ascii) in al
error: error: