1 1fd6a248 2024-09-28 benni [bits 16]
 2 1fd6a248 2024-09-28 benni [cpu 286]
 3 1fd6a248 2024-09-28 benni 
 4 1fd6a248 2024-09-28 benni 
 5 495884c2 2024-10-05 benni NUM_SECTORS equ 16
 6 a1cd4b7f 2024-10-03 benni 
 7 a1cd4b7f 2024-10-03 benni section .boot exec write
 8 a1cd4b7f 2024-10-03 benni global _start
 9 a1cd4b7f 2024-10-03 benni extern _entry
10 1fd6a248 2024-09-28 benni _start:
11 a1cd4b7f 2024-10-03 benni 	mov byte [bootdrv], dl
12 a1cd4b7f 2024-10-03 benni 
13 a1cd4b7f 2024-10-03 benni 	; reset boot drive
14 a1cd4b7f 2024-10-03 benni 	xor ah, ah
15 a1cd4b7f 2024-10-03 benni 	mov dl, byte [bootdrv]
16 a1cd4b7f 2024-10-03 benni 	int 0x13
17 a1cd4b7f 2024-10-03 benni 	jc error
18 a1cd4b7f 2024-10-03 benni 
19 a1cd4b7f 2024-10-03 benni .loop:
20 a64d9d6e 2024-10-05 benni 	lea bp, [ldstr]
21 a64d9d6e 2024-10-05 benni 	call puts
22 a64d9d6e 2024-10-05 benni 
23 a1cd4b7f 2024-10-03 benni 	; read sectors
24 0d51402e 2024-10-05 benni 	stc
25 1fd6a248 2024-09-28 benni 	mov ah, 0x02
26 a1cd4b7f 2024-10-03 benni 	mov al, NUM_SECTORS
27 a1cd4b7f 2024-10-03 benni 	xor ch, ch
28 1fd6a248 2024-09-28 benni 	mov cl, 2
29 a1cd4b7f 2024-10-03 benni 	xor dh, dh
30 a1cd4b7f 2024-10-03 benni 	mov dl, byte [bootdrv]
31 a1cd4b7f 2024-10-03 benni 	mov bx, 0x1000
32 1fd6a248 2024-09-28 benni 	mov es, bx
33 1fd6a248 2024-09-28 benni 	xor bx, bx
34 1fd6a248 2024-09-28 benni 	int 0x13
35 a1cd4b7f 2024-10-03 benni 	jnc .ok
36 1fd6a248 2024-09-28 benni 
37 a1cd4b7f 2024-10-03 benni 	; reset boot drive again
38 0d51402e 2024-10-05 benni 	stc
39 a1cd4b7f 2024-10-03 benni 	xor ah, ah
40 a1cd4b7f 2024-10-03 benni 	mov dl, byte [bootdrv]
41 a1cd4b7f 2024-10-03 benni 	int 0x13
42 a1cd4b7f 2024-10-03 benni 	jnc error
43 1fd6a248 2024-09-28 benni 
44 a1cd4b7f 2024-10-03 benni 	dec byte [tries]
45 a1cd4b7f 2024-10-03 benni 	jnz .loop
46 a1cd4b7f 2024-10-03 benni 	jmp error
47 1fd6a248 2024-09-28 benni 
48 a1cd4b7f 2024-10-03 benni .ok:
49 a1cd4b7f 2024-10-03 benni 	push word [bootdrv]
50 a1cd4b7f 2024-10-03 benni 	mov ax, 0x1000
51 1fd6a248 2024-09-28 benni 	mov ds, ax
52 1fd6a248 2024-09-28 benni 	mov es, ax
53 a1cd4b7f 2024-10-03 benni 	jmp 0x1000:_entry
54 1fd6a248 2024-09-28 benni 
55 a1cd4b7f 2024-10-03 benni error:
56 a1cd4b7f 2024-10-03 benni 	lea bp, [errstr]
57 a1cd4b7f 2024-10-03 benni 	; fallthrough
58 1fd6a248 2024-09-28 benni 
59 a1cd4b7f 2024-10-03 benni puts:
60 a1cd4b7f 2024-10-03 benni 	mov al, byte [bp]
61 a1cd4b7f 2024-10-03 benni 	inc bp
62 a1cd4b7f 2024-10-03 benni 	test al, al
63 a1cd4b7f 2024-10-03 benni 	jz .ret
64 1fd6a248 2024-09-28 benni 
65 a1cd4b7f 2024-10-03 benni 	mov ah, 0x0E
66 a1cd4b7f 2024-10-03 benni 	xor bx, bx
67 a1cd4b7f 2024-10-03 benni 	int 0x10
68 a1cd4b7f 2024-10-03 benni 	jmp puts
69 1fd6a248 2024-09-28 benni 
70 a1cd4b7f 2024-10-03 benni .ret:
71 a1cd4b7f 2024-10-03 benni 	ret
72 1fd6a248 2024-09-28 benni 
73 a64d9d6e 2024-10-05 benni ldstr:
74 a64d9d6e 2024-10-05 benni 	db "Loading kernel...", 13, 10, 0
75 a64d9d6e 2024-10-05 benni 
76 a1cd4b7f 2024-10-03 benni errstr:
77 a1cd4b7f 2024-10-03 benni 	db "Error", 13, 10, 0
78 1fd6a248 2024-09-28 benni 
79 a1cd4b7f 2024-10-03 benni bootdrv:
80 a1cd4b7f 2024-10-03 benni 	db 0
81 a1cd4b7f 2024-10-03 benni 
82 a1cd4b7f 2024-10-03 benni tries:
83 0d51402e 2024-10-05 benni 	db 5
84 a1cd4b7f 2024-10-03 benni 
85 1fd6a248 2024-09-28 benni times 510 - ($ - $$) db 0
86 1fd6a248 2024-09-28 benni dw 0xAA55