Re: Low-level programming in Ada?

[Eryndlia Mavourneen <eryndlia@gmail.com>]

On Wednesday, August 7, 2013 11:39:58 PM UTC-5, Paul Rubin wrote:
> I'm wondering if anyone can suggest a reference (preferably online)
> about low-level programming (e.g. for operating system implementation)
> in Ada.  Not about the language itself, but examples of dealing with
> machine addresses, device registers, page tables, memory management,
> etc., preferably without dropping to assembler more than a tiny bit.
> 
> This isn't for a specific project or anything like that.  It's just
> general interest in how to do this stuff that's traditionally the domain
> of C.
> 
> Thanks.

with System;
package Addresses is
  Data_Address : constant System.Address_Type := 16#22000#;
  Data : Integer;
  for Data'Address use Data_Address;
begin
  Data := 555;
end Addresses;

Of course, for device registers and the like, you will want to use record representation clauses to specify the bit fields, etc.

Using these techniques will allow you to delve into the dark world of virtual-to-physical address translation, paging, or what-have-you.  :-)

All of this is sooooo much easier than messing around with offsets, shifts, and such in C and its offspring.

-- Eryndlia (KK1T)