Review of Embedded Linux Book

An Anonymous Coward writes "LinuxDevices.com has just published a very detailed review by Jerry Epplin of the new book by Craig Hollabaugh, Embedded Linux -- Hardware, Software, and Interfacing, published by Addison Wesley Professional. Quoting briefly from the review, "A system developer planning to use Linux for an embedded design is faced with a number of decisions, not the least of which is whether to use a packaged commercial Embedded Linux distribution or to devise a homebrew solution from the available free tools and components. The custom approach has much appeal because of its low cost and radical flexibility, allowing one to choose any approach or tool rather than those chosen by the toolkit vendor. But with this flexibility and low cost comes the chaotic documentation typical of Linux. Thus, books like [this one] fill a significant void . . .""

Comments

Interesting but

[RTFA Man]

The only disagreement I have with this is Hollabaugh's philosophy regarding non-x86 architectures. He contends, "This book's examples show that working with the [ARM-based] MediaEngine and the [PowerPC-based] RPX-CLLF was as easy as working with the [x86-based] MZ104."

This assertion is hard to credit -- even with the author's well-written scripts, acquiring and building cross-development GNU toolchains certainly takes more time than simply using those already provided on your desktop computer.

Hollabaugh had to modify the netcat source in order to compile it for ARM, show that even the author himself has had his share of trouble working with non-x86 architectures. The lesson is certainly not that x86 should be the only architecture considered, but it is fair to say that a slight bias toward x86-based devices is prudent when choosing embedded Linux target platforms because of the maturity of Linux on that architecture.

Re:Interesting but

[JKR]

I agree with you 100%. The GNU tool chain is not a no-brainer on non-x86 platforms, presumably because the projects rely on testing feedback to find and fix bugs.

For my first (PPC-based) project where I tried to build a toolchain from scratch I had real problems finding a mutually compatible set of binutils, gcc & glibc that could successfully compile QT Embedded (i.e. C++).

I think this presents a real problem for business. The source code is freely available, but some feature or other doesn't work on your chosen platform without extra patches (gcc in particular, but also glibc). The appropriate set patches is hard to find - Redhat and Montavista know about them, but they ain't telling because their business model effectively revolves around knowing what you need to do to make the software work. So, "Open Source" becomes "Closed Knowledge" because at the end of the day, everyone needs to make money and if the source is free, then charge for the knowledge / expertise.

This makes support an interesting proposition - you get companies who will help you, but only by doling out the information a piece at a time - because in their marketplace, knowledge is power.

Now, Montevista supply (excellent, patched and working) toolchains for all their supported platforms for "free" (or rather the cost of downloading 3 ISO images). By doing so, they effectively try to lock you in to their support model (which is around $10,000 a year for a single point-of-contact), especially when you discover that the range of BSPs they ship is pretty small, and expensive to add to - you're on your own if you're platform isn't on the list.

In the end, it's no better than proprietry solutions - just different.

Jon