Not the whole screenbuffer width was accessible

src/framebuffer.asm

@@ -17,7 +17,8 @@ putpixel:
 	add edi, eax
 
 	mov eax, [ebp+8]   ;x
-	mul byte [mbootinfo.fb_bytespp]
+	movzx ebx, byte [mbootinfo.fb_bytespp]
+	mul ebx
 	add edi, eax
 
 

src/start32.asm

@@ -98,6 +98,15 @@ start:
 
 	add esp, 36	;Clean reserved uitoa return string from stack
 
+	; Draw a test pixel to bottom right corner
+	mov eax, 0xff
+	mov ebx, 767
+	mov ecx, 1023
+	push 0xff
+	push 767
+	push 1023
+	call putpixel
+	add esp, 3*4
 
 rOSkalogodraw:
 	mov esi, roskalogo