Re: How do I write directly to a memory address?

[mockturtle <framefritti@gmail.com>]

> Below is an
> example of code I would like to be able to implement.
> 
> ...
> unsigned int print(char *message, unsigned int line)
> {
> 	char *vidmem = (char *) 0xb8000;
> 	unsigned int i= 0;
>

I do not have any experience about this part of Ada, but maybe I can give you a "pointer" to some bootstrapping information.  Maybe you could want to use an attribute representation  clause for Vidmem'Address (see Section 13.3 of the RM) . With some improvisation, I would write something like 

   type Vidmem_Array is array (natural range <>) of Character;
   Vidmem : Vidmem_Array (0 .. Max_Size);

   for Vidmem'Address use 16#000B_8000#;

Note that  with this approach you need to know the maximum size of your "buffer".  Otherwise, you could go through System.Address (see 13.7 and following of the RM).

As disclaimed above, I am not an expert on this, so maybe someone could want to integrate/correct/whatever the information above.

   
 
> 	i=(line*80*2);
> 
> 	while(*message!=0) // 24h
> 	{
> 		vidmem[i]= *message;
> 		*message++;
> 		i++;
> 		vidmem[i]= 0x7;
> 		i++;
> 	};
> 
> 	return(1);
> };
> ...