Re: [elysium-developers] IDE code

[Kasper V. L. <ve...@da...>]

> Well, I've decided that I hate floppy drives, so I've gone onto hard drives.
> The code currently:
> * Scans and autodectects IDE drives
> * The FAT16 code is good enough to list the root directory without hard coded
>   sector numbers

This is good news :-)
 
> I'm going to brush it up before a posting. Still no word on capabilites, Kasper?

I agree that 'real' capabilities would be a better way of doing it.
There are some issues about how to create a capability, though. I think
the kernel should create the capabilities, but that requires that the
kernel is able to check whether or not a process has access to some
resource. If the resource is managed by a server it's not trivial to
figure out the best way of doing it. It would be great if servers
(drivers), such as the keyboard server, could use capability based
protection of the resources it manages. I'll elaborate in a later
posting.
 
> Where will the IDE code go in the end? I don't think it can securly go in
> process code - it would be too easy for a rouge process to do damage. I doubt
> it will go in the kernel, so will there be a 'Drive Server'?

I expect we'll implement a 'disk block server'. The way it multiplexes
the disk blocks will be explained later (it's rather complex - probably
the most complex driver of all), but interested people should read 'The
Exokernel Operating Systems Architecture' by D. R. Engler. Especially
the chapter(s) about XN.

-- 
-------------------------------------------------------------------
Kasper Verdich Lund, Computer Science Department, Aarhus University
Office: 34P.218              | Phone: (+45) 8942 5680
Email:  ve...@da...  | WWW: http://www.daimi.au.dk/~verdich