Date: Wed, 2 Jan 2008 22:08:50 -0800 From: Marcel Moolenaar <xcllnt@mac.com> To: Rafal Jaworowski <raj@semihalf.com> Cc: embedded@freebsd.org Subject: Re: ocpbus(4) Message-ID: <838C48EA-C7C9-468C-8A3B-E51A1EE7D10E@mac.com> In-Reply-To: <477BF1FB.8080104@semihalf.com> References: <B56F8F3C-7872-47B9-8154-1C08F5BEEA3D@juniper.net> <477BF1FB.8080104@semihalf.com>
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On Jan 2, 2008, at 12:20 PM, Rafal Jaworowski wrote: > While the discussion so far went around units enumeration and > instantiation, > for me the most problematic to model in a generic way are attributes > and > settings in layer 3. Most often they are things that need to be > known in > advance for a particular system, and that are not always uniform, > examples: > > - IRQ lines routing > - multi-purpose pins (GPIO and alike) configuration (USB/IrDA/ > interrupt/whatever) > - I2C devices addresses > - phy-to-MAC mapping (in case of a multi port Ethernet), MAC > addresses themselves > - on-board logic (FPGA, CPLD) configuration > > Those are not attributes of SoC family, but are a custom setup and > usually do > not have an unique ID or so that would let us differentiate it from > others > based on the same chip. The information on the above is also not > always > available from firmware, so we need to deal with this in kernel. So my > question is about where these would fit in and how do we manage > those, so > there's clear separation of configuration for a given system? Most of it seems to fit best in the hardware layer and I expect that there's where we initially want to put it. Given the unstructured nature of the information, we may actually end up scattering it across the layers. > Finally I have a minor note to not confuse entities :) e500 is a CPU > core > (that has a couple of versions on its own), so mostly what has been > said in > this thread regarding on-chip devices, resources, local busses, other > properites etc. pertains to the SoC (MPC85xx), not the core. Oh, picky picky picky :-) Seriously: you're right of course. -- Marcel Moolenaar marcelm@juniper.net -- Marcel Moolenaar xcllnt@mac.com
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