X-Git-Url: http://git.dujemihanovic.xyz/posts?a=blobdiff_plain;f=boot.s;h=51be5d92dd8ee19426be4092d2aaed2c1e96f46d;hb=eec791adfbaddde2f5724e0f5c7319e7d2aaef0e;hp=50730d0c39dd9566f3eef2e0b87582758af13444;hpb=4326df7844154f8c575a33b3898709944e08f74b;p=nameless-os.git

diff --git a/boot.s b/boot.s
index 50730d0..51be5d9 100644
--- a/boot.s
+++ b/boot.s
@@ -1,22 +1,71 @@
 	bits 16 ; boot sectors run in real mode
-	org 7c00h ; boot sector is always loaded at 0x7c00
-
-	mov al, 1 ; update cursor after write
-	mov bh, 0 ; write to page 0
-	mov bl, 00000111b ; attribute: high nibble is foreground (light gray),
-					  ; low nibble is background (black)
-					  ; NOTE: in the binary, these will be inverted, so low nibble here will become high nibble in binary and vice versa!
-	mov cx, msg1end - msg1 ; size of message
-	mov dl, 0 ; column to write to
-	mov dh, 0 ; row to write to
-	push cs ; push code segment to stack
-	pop es ; pop pushed code segment to extra segment, this serves as the base to the string
-	mov bp, msg1 ; offset where the string is
-	mov ah, 13h ; write string subservice 
-	int 10h ; call BIOS interrupt 0x10
-	jmp msg1end ; jmp to endless loop
-	msg1 db "Gotta start somewhere"
-	msg1end: jmp msg1end
+	org 7c00h ; boot sector is loaded at 0x7c00
+
+_start
+	mov di, printing_numbers
+	call print
+
+	or bl, 1
+	mov dx, 0DEADh ; number to print
+	call print_word
+	
+	mov di, space
+	call print
+	
+	xor bl, bl
+	mov dx, 0BEEFh
+	call print_word
+
+	mov di, waiting
+	call print
+
+	mov di, keystroke
+	mov bl, 1
+
+.loop
+	mov ah, 0
+	int 16h
+	cmp ah, 1Ch
+	je .enterpressed
+	jmp .continue
+	cmp ah, 0Eh
+	je .backspace
+	jmp .continue
+.enterpressed
+	pusha
+	mov ah, 0Eh
+	mov al, 0Dh
+	int 10h
+	mov al, 0Ah
+	int 10h
+	popa
+	jmp .loop
+.backspace
+	pusha
+	mov ah, 03h
+	mov bh, 0
+	int 10h
+	dec dl
+	mov ah, 02h
+	int 10h
+	mov ah, 0Eh
+	mov al, ' '
+	int 10h
+	mov ah, 02h
+	int 10h
+	popa
+	jmp .loop
+.continue
+	mov [keystroke], al
+	call print
+	jmp .loop
+
+printing_numbers db "Printing some random hex numbers", 0
+waiting db "I await keystrokes", 0
+keystroke db "$", 0
+space db " ", 0
+
+%include "print.s"
 
 	times 510-($-$$) db 0 ; fill with 0 until 0x1fc is reached
-	dw 0xaa55 ; BIOS MBR signature
+	dw 0AA55h ; BIOS MBR signature