So, when I try to compile my code
section .boot
bits 16
global boot
boot:
mov ax, 0x2401
int 0x15
mov ax, 0x3
int 0x10
mov [disk],dl
mov ah, 0x2 ;read sectors
mov al, 6 ;sectors to read
mov ch, 0 ;cylinder idx
mov dh, 0 ;head idx
mov cl, 2 ;sector idx
mov dl, [disk] ;disk idx
mov bx, copy_target;target pointer
int 0x13
cli
lgdt [gdt_pointer]
mov eax, cr0
or eax,0x1
mov cr0, eax
mov ax, DATA_SEG
mov ds, ax
mov es, ax
mov fs, ax
mov gs, ax
mov ss, ax
jmp CODE_SEG:boot2
gdt_start:
dq 0x0
gdt_code:
dw 0xFFFF
dw 0x0
db 0x0
db 10011010b
db 11001111b
db 0x0
gdt_data:
dw 0xFFFF
dw 0x0
db 0x0
db 10010010b
db 11001111b
db 0x0
gdt_end:
gdt_pointer:
dw gdt_end - gdt_start
dd gdt_start
disk:
db 0x0
CODE_SEG equ gdt_code - gdt_start
DATA_SEG equ gdt_data - gdt_start
times 510 - ($-$$) db 0
dw 0xaa55
copy_target:
bits 32
hello: db "Hello more than 512 bytes world!!",0
boot2:
mov esi,hello
mov ebx,0xb8000
.loop:
lodsb
or al,al
jz halt
or eax,0x0F00
mov word [ebx], ax
add ebx,2
jmp .loop
halt:
mov esp,kernel_stack_top
extern kmain
call kmain
cli
hlt
section .bss
align 4
kernel_stack_bottom: equ $
resb 16384 ; 16 KB
kernel_stack_top:And whenver I compile with nasm -f bin boot.asm -o boot.bin, I get boot.asm:77: error: binary output format does not support external references
Anyway to fix this? Thanks, T.M.
