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bits 16
org 0x7c3e
kernel_sectors equ 64
kernel_segment equ 0x3000
support_flags equ 0x4000
pci_hw_char equ 0x4001
pci_ver equ 0x4002
last_pci_bus equ 0x4004
pci_support equ 0x80
in al, 0x92
or al, 0x02
out 0x92, al
xor ax, ax
mov ss, ax
mov sp, 0x7ffc
mov ah, 0x01
mov ch, 0x3f
int 0x10
mov ax, kernel_segment
mov es, ax
mov ax, 0x0200 + kernel_sectors
xor bx, bx
mov cx, 0x0002
xor dh, dh
int 0x13
mov ax, 0xb101
int 0x1a
cmp edx, 0x20494350
jne no_pci
test ah, ah
jnz no_pci
mov byte [support_flags], pci_support
mov byte [pci_hw_char], al
mov word [pci_ver], bx
mov byte [last_pci_bus], cl
no_pci:
cli
lgdt [gdt]
mov eax, cr0
or al, 0x01
mov cr0, eax
jmp 0x08:pmode
bits 32
pmode:
mov ax, 0x10
mov ds, ax
mov ss, ax
mov esp, 0x00040000
xor ebp, ebp
call kernel_segment * 16
halt:
hlt
jmp halt
times $$ + 0x018a - $ db 0
;0x7dc8
gdt:
dw .e - .t
dd .t
.t:
dq 0x0000_0000_0000_0000
dq 0x00c0_9a00_0000_0037
dq 0x00c1_9200_0000_ffff
dq 0x0000_0000_0000_0000;TODO: task
dq 0x0000_0000_0000_0000
dq 0x0000_0000_0000_0000
.e:
dw 0xaa55
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