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more work to make our assembly initialization more beautiful

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This commit is contained in:
Steffen Vogel 2013-10-17 21:35:13 +02:00
parent 3e73d6384e
commit d59676dbf5
1 changed files with 50 additions and 50 deletions
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100
arch/x86/kernel/entry64.asm
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@ -89,10 +89,10 @@ SECTION .data
global boot_pml4 global boot_pml4
ALIGN 4096 ; of course, the page tables have to be page aligned ALIGN 4096 ; of course, the page tables have to be page aligned
MAP_ENTRIES equ 512 MAP_ENTRIES equ 512
boot_pml4 times 512 DQ 0 boot_pml4 times MAP_ENTRIES DQ 0
boot_pdpt times 512 DQ 0 boot_pdpt times MAP_ENTRIES DQ 0
boot_pd times 512 DQ 0 boot_pd times MAP_ENTRIES DQ 0
boot_pt times (MAP_ENTRIES*512) DQ 0 boot_pt times (MAP_ENTRIES*MAP_ENTRIES) DQ 0 ; 1GB kernel space
SECTION .text SECTION .text
ALIGN 8 ALIGN 8
@ -228,10 +228,27 @@ cpu_init:
mov cr4, eax mov cr4, eax
ret ret
; identity map a single page at address eax
identity_page:
push edi
push ebx
and eax, 0xFFFFF000
mov edi, eax
shr edi, 9 ; (edi >> 12) * 8 (index for boot_pt)
add edi, boot_pt
mov ebx, eax
or ebx, 0x13 ; set present, writable and cache disable bits
mov DWORD [edi], ebx
pop ebx
pop edi
ret
ALIGN 4 ALIGN 4
stublet: stublet:
mov esp, startup_stack-4 mov esp, startup_stack-4
; save pointer to the multiboot structure ; save pointer to the Multiboot structure
push ebx push ebx
; initialize cpu features ; initialize cpu features
call cpu_init call cpu_init
@ -240,7 +257,7 @@ stublet:
; check if lapic is available ; check if lapic is available
call check_lapic call check_lapic
; find MP Floating Pointer Structure ; find MP Floating Pointer structure
push DWORD 0x100000 push DWORD 0x100000
push DWORD 0xF0000 push DWORD 0xF0000
call search_mps call search_mps
@ -258,60 +275,37 @@ stublet:
je map_kernel je map_kernel
map_mps: map_mps:
; map MP Floating Pointer Structure ; map MP Floating Pointer structure
mov DWORD [apic_mp], eax mov DWORD [apic_mp], eax
mov edi, eax call identity_page
and edi, 0xFFFFF000
shr edi, 9 ; (edi >> 12) * 8
add edi, boot_pt
mov ebx, eax
and ebx, 0xFFFFF000
or ebx, 0x00000013
mov DWORD [edi], ebx
; map mp_config ; map MP Configuration table
mov edi, [eax+4] mov eax, [apic_mp+4]
and edi, 0xFFFFF000 call identity_page
shr edi, 9 ; (edi >> 12) * 8
add edi, boot_pt
mov ebx, [eax+4]
and ebx, 0xFFFFF000
or ebx, 0x00000013
mov DWORD [edi], ebx
%ifdef CONFIG_VGA %ifdef CONFIG_VGA
map_vga: ; map VGA textmode plane
mov edi, 0xB8000 mov eax, 0xB8000
shr edi, 9 ; (edi >> 12) * 8 call identity_page
add edi, boot_pt
mov ebx, 0xB8000
or ebx, 0x00000013
mov DWORD [edi], ebx
%endif %endif
map_multiboot: ; map Multiboot structure
mov edi, [esp] mov eax, [esp] ; pointer is still on the stack
and edi, 0xFFFFF000 call identity_page
shr edi, 9 ; (edi >> 12) * 8
add edi, boot_pt
mov ebx, [esp]
and ebx, 0xFFFFF000
or ebx, 0x00000003
mov DWORD [edi], ebx
map_kernel: map_kernel:
mov edi, kernel_start mov edi, kernel_start
shr edi, 9 ; (kernel_start >> 12) * 8 shr edi, 9 ; (edi >> 12) * 8 (index for boot_pt)
add edi, boot_pt add edi, boot_pt
mov ebx, kernel_start mov ebx, kernel_start
or ebx, 0x00000003 or ebx, 0x00000003 ; set present and writable flags
mov ecx, kernel_end ; determine kernel size in number of pages mov ecx, kernel_end ; determine kernel size in number of pages
sub ecx, kernel_start sub ecx, kernel_start
shr ecx, 12 shr ecx, 12
inc ecx inc ecx
.l1: .l1:
mov DWORD [edi], ebx ; Set the double word at the destination index to the B-register. mov DWORD [edi], ebx
add edi, 8 add edi, 8
add ebx, 0x1000 add ebx, 0x1000
loop .l1 loop .l1
@ -319,18 +313,24 @@ map_kernel:
init_paging: init_paging:
mov edi, boot_pml4 mov edi, boot_pml4
mov cr3, edi mov cr3, edi
; So lets make PML4T[0] point to the PDPT and so on:
mov DWORD [edi], boot_pdpt ; Set the double word at the destination index to pdpt. mov DWORD [edi], boot_pdpt
or DWORD [edi], 0x00000003 ; Set present and writeable bit or DWORD [edi], 0x3
add edi, MAP_ENTRIES-1 ; create self reference for recursive paging
mov DWORD [edi], boot_pml4 ; boot_pml4[511] -> boot_pml4
or DWORD [edi], 0x3 ; set present and writable flags
mov edi, boot_pdpt mov edi, boot_pdpt
mov DWORD [edi], boot_pd ; Set the double word at the destination index to pd. mov DWORD [edi], boot_pd
or DWORD [edi], 0x00000003 ; Set present and writeable bit or DWORD [edi], 0x3 ; set present and writable flags
mov edi, boot_pd mov edi, boot_pd
mov ebx, boot_pt mov ebx, boot_pt
mov ecx, MAP_ENTRIES mov ecx, MAP_ENTRIES
.l1: .l1:
mov DWORD [edi], ebx ; Set the double word at the destination index to pt. mov DWORD [edi], ebx
or DWORD [edi], 0x00000003 ; Set present and writeable bit or DWORD [edi], 0x3 ; set present and writable flags
add edi, 8 add edi, 8
add ebx, 0x1000 add ebx, 0x1000
loop .l1 loop .l1