Re: DDE Linux26 in the Hurd

[Samuel Thibault]

Da Zheng, le Thu 28 Jan 2010 22:06:44 +0800, a écrit :
> On 10-1-28 下午9:39, Björn Döbel wrote:
> >> You missed my point. I understand that each driver runs in a separate 
> >> program.
> >> The problem is that a device has to find the bus where it is located. In 
> >> the
> >> current implementation, a driver can only scan 32 devices. If we have 33 
> >> devices
> >> in the system, its driver thinks there isn't such a device and fails to 
> >> work.
> >>
> >> So I suggest why not let the logical bus contains all devices in the 
> >> system.
> > 
> > Because in a secure system you don't want the NIC device driver to see
> > all other devices. This is why we need an IO manager that manages access
> > to devices on a per-driver basis.
> I thought only root could run drivers.

There is no strict architecture limitation (it doesn't even know what
root is).  Provided the kernel gives I/O permission to a task or
projects MMI/O, the latter can run a driver.

Samuel