basic-kernel/loader3.asm at master · AnwarShah/basic-kernel · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
#make_boot#
org 7c00h  ; loaded at 0000:7c00h

jmp start

; Data section
;----------------------------------
loading db "Loading the kernel ........................................................................................"
loading_end:
ld_completed   db  0dh, 0ah, 0dh, 0ah, "Loading Completed. Press any key to jump to the kernel"
ld_completed_e:


macro loading_cmpl_msg

	MOV	AH,	13H		; string function
	MOV	al,	1		; update cursor
	inc dh
	inc dh
	mov	dl, 0
	mov	bp,	offset ld_completed
	mov cx,	ld_completed_e - offset ld_completed

	mov	bh,	0
	mov	bl,	0000_1011b
	int 10h


endm


; Code section
;-----------------------------------
start:

; set data segment and extra segment
xor ax,ax
push cs
push cs
pop ds
pop es

; initialize the stack
mov     ax, 07c0h
mov     ss, ax
mov     sp, 03feh ; top of the stack.

; set display mode
mov ah, 0h
mov al, 03h
int 10h

; set cursor mode
mov ah, 1h
mov ch, 6       ; starting line
mov cl, 7       ; ending line
int 10h

; print loading message
call loading_msg
loading_cmpl_msg

; wait for keystroke
mov ah,     0h
int 16h

; load the kernel at 0800h:0000
mov     ah,     02h     ; read sector function
mov     al,     10   ;load 10 sector
mov     ch,     0    ; cylinder 0
mov     cl,     2    ; start at sector 2
mov     dh,     0    ; head
mov     dl,     0    ; dl not changed
; es:bs points to data buffer
mov     bx,     0800h
mov     es,     bx
mov     bx,     0

; read sector
int 13h

; pass control to the kernel
jmp 0800h:0000h   ; go to the kernel


; Procedure section
;-----------------------------------------
loading_msg proc

; print loading message
push    cx
push    si
push    ax

mov cx, loading_end - offset loading ; string size

mov si , 0  ; index

mov ah, 0eh  ; output function

next:
mov al, loading[si]   ; attributed string
int 10h
inc si

;;; wait.........
PUSH    CX
PUSH    DX
PUSH    AX

MOV        AH, 86H
MOV        CX, 0000H
MOV        DX,    0ffe8H
INT        15H

POP        AX
POP        DX
POP        CX
;;; wait

loop next

pop ax
pop si
pop cx

ret

endp ; procedure end


db  510-($-7c00H) dup(0)
DW	0AA55H			; boot signature