My BSP is going to be released as “Shared Source” so that anyone can use the BSP to run Windows Compact 7 on the device.  Shared Source is Microsoft’s version of a source code license that allows the user to do just about anything they want including putting the code in a shipping product.  It’s not ‘viral’ like GPL where the any code derived from GPL code must also be GPL.

Given the nature of GPL and the rather zealous nature of some of its proponents, I wanted to avoid any accusation that I was taking GPL code and putting it into my BSP.  To minimize that possibility, I’ve avoided looking at any source code for the Raspberry Pi’s Linux distros.  I have been reading various web sites, but I haven’t downloaded any source.  I did download a binary of a boot disk so that I could test the hardware and ensure that it works.

This clean room approach is problematic given that the full programming manual for the Broadcom BCM2835 (the CPU on the Pi) is not public.  Broadcom has provided a peripheral manual that discusses the register addresses / functions of some of the embedded peripherals but it’s not complete.  Still, throughout the project I plan to stick to my guns about not looking at the Linux port.

More soon…

They’ve been pretty hard to get one of these devices but with the help of a kind soul across the pond, I’ve managed to get hold of one.  While the Pi organization is has various versions of Linux running on the device, I’m going to develop a Windows Embedded Compact (Windows CE) Board Support Package so that I can run WEC on the device. It should be an interesting project that I’m going to document my work here in the blog.  We’ll see how it goes…

In 2011, those similarities remain features of Windows Embedded Compact 7, the latest version of Windows CE. The Win32 API, file formats, and GDI/User UI remain. However, the desktop has moved, along with the other players in the industry to a more “Internetty” style user interface where the user interface is defined in a markup language and the intelligence of the application is written in code typically referred to as “code behind” Apps following this paradigm include browser-based UIs using HTML and JavaScript, along with Flash-based apps. Microsoft has pushed Silverlight, its rich-UI, cross platform, browser based solution as its entry into this programming style. Silverlight combines a power UI description language XAML, with CPU independent managed (.NET) code as the code behind. Silverlight runs across lots of browsers and even on Mac OS X systems.

Microsoft’s Embedded team has adapted Silverlight technology for use on Windows Embedded Compact, taking the powerful XAML driven rendering engine but replacing the (somewhat problematic) managed code back end with native C++ code. Running native code dramatically decreases startup time, enables direct access to the Win32 API and drivers and avoids that annoying garbage collection pause that eliminates managed code from driving real time applications. “Silverlight for Windows Embedded”, or SWE as it’s sometimes known, is a huge differentiator for Windows Compact, providing a powerful user interface engine that simply is head and shoulders above the competition.

So, how does one write an SWE application? First, download an evaluation copy of Windows Embedded Compact 7 here. If you’re not in Korea where lightning fast broadband is the norm, expect this to take a while as the download is massive. You can also contact your local Windows Embedded Rep. to get the multi-DVD package. If you are currently developing with Windows Embedded CE 6, you’ll want to install Compact 7 on a separate machine or in a VM as CE 6 and Compact 7 can’t be installed side-by-side.

With the evaluation copy of Windows Embedded Compact 7, you’ll also get an eval copy of Expression Blend 3, which is the tool used to assist in designing the SWE application’s front end. SWE uses Blend 3 because the Silverlight rendering engine used in SWE is Silverlight 3 based.

There is a great blog post on the SWE Blog that describes your first SWE application. There are other posts on how to create a Compact 7 image that supports SWE as well as one that describes how to create a control with SWE. Unfortunately, there isn’t much activity in the blog with the last post being August of 2010. However, the content that is there is quite is informative.

There was an earlier version of SWE that shipped with Windows CE 6 Release 3. However, this version supports only Silverlight 2, is slower than the Silverlight 3 version in Compact 7 and doesn’t have the powerful translation tool that auto generates the C++ native code framework from the Blend project. Some folks that used the CE 6 R3 version came away with a bad impression. The new version in Compact 7 is much better. I hope those early adapters will give the new version a try. It’s a whole new ballgame.