>The probeget routine starts as follows:
>
>	set	KERNBASE, %o2
>	cmp	%o0, %o2		! if addr < KERNBASE
>	blu	Lfsbadaddr		!	go return error
>
>What is the point of comparing against KERNBASE?
>The problem is: on a Sun-4, zs1 lives at obio address 0, and probeget
>doesn't seem to find anything at address 0.  

hi david-

    Doesn't probeget() take a virtual address and size?    obio address
0 is a physical addresses, so you couldn't pass it directly to probeget().
the check you quoted is to make sure the virtual address the device is 
mapped to is within the kernel's virtual address space.   [at least
that's how i read it]

cheers,
chuck