Yep, Efika is a good software development platform for that kind of parallel development, but it lacks a couple of crucial features to be based for hardware-near development, which will possibly require a "real" eval board instead. A JTAG header is the obvious first one.
I disagree. Why do you need JTAG to develop application-level software? Why do you even need JTAG to develop Linux kernel software when there are plenty of kernel-level and application-level debuggers which operate over ethernet?
A closed-source commercial firmware is the second.
Right, and this stops x86 development somehow too, right? I think if you are developing hardware you need to consider licensing a firmware or spending a hell of a lot of time developing your own (or your own support for an existing Open Source firmware, at least).
It's actually far cheaper to license the Genesi Aura firmware than it is to pay an engineer to develop U-Boot support over the course of a month. It wouldn't be tenable to license it if it wasn't.
It all depends on how low-level development is required for the application.
I'm not saying those choices weren't suitable for Genesi to make, they clearly were (I doubt many current Efika users miss JTAG or firmware sources).
We have had literally 3 people express a genuine interest in JTAG. I mean, people who already own the hardware required (wigglers and host software are not cheap) and had a real need which could not be solved any other way (software or otherwise).
I get the question all the time (why eval boards are so expensive). The answer is simple: They are there to be available for customers who are serious about buying _chips_ in volume, so they can evaluate them, and they are not meant for the end-user market. There's a significant amount of support involved per customer, boards are smaller volume and that really adds up in cost.
Also, and probably most significantly, the eval board price is rarely a hurdle for those looking to develop a new system while end users are much more price sensitive.
We have several examples where companies want to evaluate the MPC5200B for a solution and have jumped at the chance to buy a working Efika for $99 rather than then $3000 Lite5200B. Remember when you want to use a new chip (and if you are on the bleeding edge as with the MPC5121E or MPC8610) then you do not know if you are going to buy a huge quantity of chips. Buying 3 or 4 development boards for your team is a huge outlay to find out that this system does not meet your needs, compared to the $400 it would cost to buy the same number of Efika systems.
What if you are a startup and just don't have $10,000 of cash you can throw into "wondering if it's a good chip or not"?
The first step is always a larger board though, ITX or something, then keep revising it down taking off the features people do not seem to use.
Exactly, and this is why the semiconductor eval boards are so often complex: so their customers can take a subset of that and base their design off of that. I'd expect that's exactly what Genesi did to make the Efika (base it on the reference design, added a few things and took off things no longer needed + add new firmware).
The Efika design is "from scratch"; it is not directly or indirectly derived from the Lite5200B except by example and reference.
There are several things done wrong on the Lite5200B design for a start. Also, why start with something so complex?
Most of the peripherals on the MPC5200B are industry standard connectivity. USB connects via one of two standard PHY connections. Ethernet MII.. AC97.. PCI.. I2C for the system management PIC.. serial port.. a lot of the design where applicable was simply dropped in from the Pegasos (I'm sure you noticed the audio connectors are identical..)
You do not need a complex development board to implement this chip or any of Freescale's similar SoC designs on a suitable board. Sometimes it is better to go for a clean slate, than to take an existing design and rip out the things you do not need. We have built a substantial library of "parts" that can drop into new designs with very little effort..
Matt Sealey, Genesi USA Inc.
Product Development Analyst