bootsector/boot.asm at master · graeme-gets/bootsector · GitHub

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;
; A Simple Boot sector to print a message
;


[org 0x7c00]

; Start Up

mov [BOOT_DRIVE], dl		; BIOS stores our boot drive in DL,so it’s	best to remember this for later.

	mov si, BOOT_MSG
	call printString
;	mov cl,0x02        ; two byte value
;	mov edx,0x1234
;	call printHex
;	mov si, NEW_LINE
;	call printString


	; read from disk

;	mov bp,0x8000				; set stack safely out of the way
;	mov sp, bp

;	mov bx, 0x9000				; Load 5 sectors to 0x0000(ES):0x9000(BX) from boot disk
;	mov dh, 5
;	mov dl, [BOOT_DRIVE]
;	call diskLoad

;	mov dx, [0x9000]			; PRIN TTH EFIRST LOADED WORD
;	mov cx,2					; print two bytes
;	call printHex

;	mov dx, [0x9000 + 512]		; prin tdata that came form 2nd sector
;	mov cx,2
;	call printHex
	jmp end


end:
; Prepare for 32 bit protected mode


	mov bp, 0x9000			; set the stack
	mov sp,bp

	mov si, MSG_REAL_MODE
	call printString

	call switch_to_pm

	jmp $	; We should never get here


; Includes
%include "print.asm"
%include "disk.asm"
%include "gdt.asm"
%include "switchPM.asm"
%include "print_string_pm.asm"
;GLOBAL VERIABLES
BOOT_MSG: db 'Loading osGG-x86', 0xa, 0xd, 0
BOOT_DRIVE: db 0


[bits 32]

BEGIN_PM:
	mov ebx, MSG_PROT_MODE
	call print_string_pm

; Global Veriables
MSG_REAL_MODE:	db "Started in 16 bit Real Mode", 0xd,0xa,0
MSG_PROT_MODE:	db "Success - We are in 32 bit protected mode",0xd,0xa,0

; Padding Bios and Magic number

	times 510-($-$$) db 0

	dw 0xaa55

	times 256 dw 0xdada
	times 256 dw 0xface