Re: [uCsimm] Himemloader for uCimm

From: Bernhard Kuhn (kuhn@lpr.e-technik.tu-muenchen.de)
Date: Sun Mar 18 2001 - 05:49:48 EST


Tom Walsh schrieb:
>
> I had thought that the 68EZ328 implementation ran
> in supervisory mode at all times?

As far as i experienced it, the supervisor mode is
only activ on kernel level, but not in user space
(as it archtecturaly should be). That is the
reason why you can't just execute a new kernel from
within user space.

BTW: A "himem-driver" /dev/himem would be a more portable
way to load and execute (by using ioctl) a new image.

The supervisor-patch is just a quickhack to easily
overcome some barriers from within user space, but loosing
multiuser capabilities: any user can invoke trap #10 and
can switch to kernel level. But with a MMU-less CPU this
might be only a minor issue ...

Bernhard
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