Re: Ada and Hardware

["chris.danx" <chris.danx@ntlworld.com>]

"Tarjei T. Jensen" <tarjei.jensen@kvaerner.com> wrote in message
news:9de8t0$e1s3@news.kvaerner.com...
>
> chris.danx wrote :
> >I don't understand FAT12 yet, and it complicates the boot sector.  Also the
> fs
> >can be messed with if it's a fat12 disk easily.  I don't want this.  Would
> you
> >want any person coming along and swapping a driver file for another that's
> got a
> >similar signiture but does malicious things behind the scenes?  What's more
> >anyone can come along and delete a critical file easy.  Two clicks and OS
> is
> >gone.
>
> That situation is no worse than anything else that boots from a standard
> msdos floppy. If I thought it would be a problem II would  make he file(s)
> invisible (system).
>

This is true, but my main reason for doing it with BFS instead of FAT12 is the
simplicity of working with the files on it.  The Boot sector is simplified
grately and so too is the secondary loader (a 32bit Ada loader with floppy
driver; the OS will have a new module reconfiguration system which is easier to
manage with Ada than ASM).  I want to limit my use of ASM in the system to the
bootsector if possible.  Everything else stands a good chance of being Ada or
maybe a teensy bit of C.

> >I know how to boot from a floppy for the file system i'm using.  It's
> really
> >easy (just look in 2nd inode to get address of primary kernel file, and
> >calculate offset).  I just need to get the files from my FAT hard disk to
> my BFS
> >floppy.  The current driver implements a disk as a file on a HD, and it's
> really
> >easy to work with.  The problem is i need to create a bfs enabled disk,
> write
> >files to it, read info from it, via an interactive shell.  I don't know how
> to
> >do this in Ada (i can do the shell though).  I do know how in C.
>
> If you know how to do it in C, you know how to do it in Ada.

I'll try a binding to C and see how it goes.