Creating a new ARM/AVR platform

[Richard Owlett]

Jacob Mansfield wrote:
> Hi All,
> My company is seeking to create a monitoring device using an ARM or AVR
> processor, and wishes it to run Linux.
> As we are developing the hardware, it can be designed completely for
> this purpose, and we would have all the technical specifications avalable.
> Could anybody point me towards a guide for porting Linux to such a platform?
> thanks!

Then wrote:
> As we would be running custom hardware, what would be required to enable the
> kernel to access it?

And also:
> That was more the information I was looking for, how to tell the
> kernal/debian/ubuntu about the specifics of the motherboard, how to use the
> graphics/ram, etc

and replied to Liam:

>> I would think some key questions would be:
>> * Do you already have a reference platform or are you building your own?
> We would be building our own hardware, completely from scratch
>
>> * Have you chosen the chipset, componentry etc.?
> All we know so far is that we will use an Intel Atom processor (that's
> now been decided)
>
>> * Failing that, are you going with COTS hardware?
> no, the hardware will be completely custom-designed
>

That combination of posts bothers me. I've not been involved 
in "from scratch" hardware development for almost thirty 
years. Does the OP realize just how large a project this is. 
There are not only not only the apparent hardware issues (eg 
can pin A of chip 2 drive all the loads attached) but PCB 
layout issues (eg can this output line be run that close to 
a specific input line OR how wide a trace is needed to 
handle the power requirements of the last chip in line). How 
will the device be enclosed (does it need to be weather 
proof OR are there restrictions on where the power cord 
goes)? Then you get into the regulatory morass if you wish 
to sell (safety under UL, CSA etc, electronic emissions 
under FCC and VDE).

We won't even glance at the man-years that could be involved.