Re: Porting To New System

[Alan Cox <alan@lxorguk.ukuu.org.uk>]

On Gwe, 2005-05-27 at 18:30, Stanislaw Skowronek wrote:
> >  Does the firmware give you the ability to control MMU mappings ?
> 
> I think we won't - this would be a serious security bug.

That depends who the device is defending against and how. MMU control
cuts both ways in game consoles (if present) - it makes it harder to
defend the console from a hostile writer, but it also makes it easier
for the game authors to debug and to trap/recover from errors when the
game is deployed.

For ucLinux you essentially need a console, an input device (keyboard
etc), a storage device, the ability to allocate memory and a timer
interrupt/callback. Absolutely everything else is optional. So you can
probably run ucLinux as a 'game' which allocates lots of memory,
requests a timer callback and drives the entire world through the
firmware. Whether you can do non-ucLinux depends on MMU access and
control. If you've got some kind of MMU interface then you've probably
got sufficient to do a full Linux but ucLinux would still be a natural
stepping stone in exploration.

Alan