We uhh.... ran out of space

boot.asm

@@ -7,7 +7,7 @@ OS_SEGMENT equ 0x100
 boot:
     ; Load from disk
     mov ah, 0x02 ; read
-    mov al, 0x01 ; No of sectors (1)
+    mov al, 0x02 ; No of sectors (1)
     mov cl, 0x02 ; Sector start (1 = boot sector, 2 = OS)
     mov ch, 0x00 ; Cylinder 0
     mov dh, 0x00 ; Head 0

gfx/cvbmp.py

@@ -5,8 +5,8 @@ pixels = list(im.getdata())
 w, h = im.size
 
 with open('gfxd_cursor.asm', 'w') as f:
-    f.write(f'gfxd_cursor_dim: db {w} db {h}\n')
-    f.write('gfxd_cursor: ')
+    f.write(f'gfxd_cursor_dim: db {w}, {h}\n')
+    f.write('gfxd_cursor: db ')
 
     for px in pixels:
         if px == (255, 255, 255, 255):
@@ -15,4 +15,4 @@ with open('gfxd_cursor.asm', 'w') as f:
             c = '0x00'
         else:
             c = '0xFF'
-        f.write(f'db {c} ')
+        f.write(f'{c}, ')

gfx_util.asm

@@ -1,5 +1,14 @@
+; Constants
 VMEM equ 0xA000
 
+; Initializes 320x200 8-bit/256-color (13h) video graphics mode
+gfx_init_vga13:
+    push ax
+    mov ax, 0x0013
+    int 0x10
+    pop ax
+    ret
+
 ; di = y*32+x
 ; ax = width
 ; bl = height
@@ -68,3 +77,45 @@ gfx_rect:
 
     popa
     ret
+
+
+; di = y*32+x
+; si = source color data
+; ax = width
+; bl = height
+
+; ax/bl = 0 is undefined behavior. Don't do it.
+; (To be clear, in the current implementation it just halts)
+
+_gfx_blit0:
+    pusha
+
+    push VMEM
+    pop es
+
+    mov dl, 0 ; row counter
+
+    .row:
+        add dl, 1
+
+        mov cx, 0 ; col counter
+
+        .col:
+            add cx, 1
+
+            mov dh, [si]
+            mov [es:di], dh
+            add di, 1
+            add si, 1
+
+            cmp cx, ax
+            jnz .col
+        
+        sub di, ax ; di - width + 320. == x=x1; y++
+        add di, 320
+
+        cmp dl, bl
+        jnz .row
+
+    popa
+    ret

main.asm

@@ -18,16 +18,13 @@ section KERNEL follows=BOOTSECTOR vstart=1000h
 %endmacro
 
 main:
-    mov ax, 0x0013
-    int 0x10
+    call gfx_init_vga13
 
-    mov cx, 50 ; x
-    mov al, 50 ; y
-    mov dx, 100 ; w
-    mov bl, 100 ; h
-    mov bh, 0x01 ; color = Dark blue
-
-    call gfx_rect
+    mov di, 0
+    mov si, gfxd_cursor
+    mov ax, 11
+    mov bl, 18
+    call _gfx_blit0
 
 jmp $ ; Halt
     
@@ -39,3 +36,5 @@ jmp $ ; Halt
 ; Data
 HELLO_WORLD:
     db 'Hello, world! :D', 0
+
+%include "gfx/gfxd_cursor.asm"