OSDev.org

Posted: **Fri Aug 24, 2012 9:16 am**

Hello everybody!

I was happily developing my own kernel and it worked great!
But something went wrong...

This code worked:

void putch (const char character) {
	volatile ushort *where;
	where = (ushort*)0xb8000 + (1 * 2);
	*where = character | (0x0f << 8);
}

But this one didn't!!

void putch (const char character) {
	volatile ushort *where;
	ushort x = 1;
	where = (ushort*)0xb8000 + (x * 2);
	*where = character | (0x0f << 8);
}

While the first code prints the character on the screen, the second does nothing!! ):

Posted: **Fri Aug 24, 2012 12:50 pm**

My crystal ball says you're either using CLI;HLT; in a VM or you're not using your compiler properly.

Posted: **Fri Aug 24, 2012 1:38 pm**

Use bochs debugger, use it one more time, do it harder! (:

Posted: **Fri Aug 24, 2012 1:43 pm**

It may not be the root cause but...

ushort x = 1;
where = (ushort*)0xb8000 + (x * 2);

You are mixing ushort for pointer arithmetic, it's not a good habit, try:

uintptr_t x = 1;
where = (uint16_t*)( (uintptr_t)0xb8000 + x*2 );

Posted: **Sat Aug 25, 2012 2:24 am**

There's no need for uintptr_t there. But yes, I would also like to complain about using ushort, which doesn't exist.

Text printing not working (C)