Subject: Re: ARM PCI init.
To: None <>
From: Snorlax <>
List: port-arm
Date: 01/22/2004 12:27:41
> On Wed, Jan 21, 2004 at 07:38:29PM +0100, Snorlax wrote:
> >    How much does NetBSD scan into the PCI config of the target platform?
> That depends on the specific platform.  A number of ports (re)configure
> the PCI bus.  Some ports have firmware that takes care of all of the
> configuration and NetBSD just inherits it.
> >    "Some  bits  are critical to PCI Controller's operation and should
> >    be controlled by illegal software."
> What's your definition of "illegal software" in this context?
> -allen

The platform uses an ARM920T processor. The same one as used on the evbarm
I'm just asking to know how much I have to modify the modify the sample
bootloader that Samsung provides to make it fit my system and load NetBSD.
That bootloader sets up the PCI memory mappings, but I also know it is
possible for the OS to reassign PCI memory space as you mention. This system
just doesn't have loads of memory to fiddle around with, let alone virtual
memory at all.
I would like the system to be able to fit into a 16MB memory footprint, but
I'm a little worried about that the 3 PCI memory address bars can be
reallocated pretty much everywhere within 2 x 32Mbytes depending on the
configuration type : )

"Illegal software" was a funny term used in regards to modifying the PCI
Control and Status Register (PCICON). Its mostly regarding the RDY[9],
CFD[8], ATS[4], ARB[1] and HST[0] bits. RDY[9] and CFD[8] could be used in a
reconfiguration scheme by NetBSD where the rest should kindly be left alone.