Linux, Windows and rPi

Yes, I heard that it always was on some form of Linux, but AFAIK its some secret proprietary flavour.

I expect the generic Chinese sat navs running WinCE6 will continue to be

in a hurry I bought an Android tablet, checking eBay you can now get a 7

At it's peak Windows CE had a significant portion of the mobile device market (PDAs as they were then), as it was very easy to develop for being a cut down Win-NT system.

It's market share was an order of magnitude grater than any of Microsoft's later phone based OS's, which have been comprehensively ignored by manufacturers, developers, and all but the lowest budget consumers.

---druck

Unfortunately, some of us have space limitations. In my case I a 3.5" screen is fine. I can just about get away with a 4.2" satnav provided it has reasonably a narrow bezel. A 5" screen hides too much of my control panel panel and, before you ask, the same would apply to most current phones.

This picture which shows my navigation software running on a 3.5" Binatone:

There is no way the PNA can be moved further to the right because it already touches the cockpit side and, as you can see, even a 4.2" display would be starting to hide the FLARM display and radio.

I believe if you check, a "secret proprietary flavour" of Linux is not allowed by the license.

Not criticizing, just curious, is "flavour" the British spelling of the American "flavor"?

No. Flavor is am American spelling of the correct form: 'Flavour'

What license is the kernel under? I'd supposed that it was GPLed.

IIRC the GPL says that you have to make the GPLed code you're using and any mods to it available to users under the GPL and pass the changes back to the original author.

However, I'd think it could be a bit different for the Linux kernel, because the changes you'd make when porting the kernel to new hardware would most likely all be the addition of separate modules such as the boot loader, drivers and other hardware-specific modules or stuff needed to let the system boot without user interaction. Since these are separately compiled code and not part of the GPLed kernel, which wouldn't need any changes if you used GCC or a compatible compiler, I don't think they have to be GPLed. AFAIK that's always been the case for GPLed code and has certainly always been the case for LGPLed code.

You're encouraged to GPL your original parts of the combined ensemble, but don't have to and can even, if you wish, use a proprietary license for it and distribute it only as binary.

I read GPLv2 and LGPLv2 very carefully when they were released and have always used them for my own stuff.

Yes. Its a common pattern: this particular British->American spelling change occurs in a few places: as well as flavour->flavor there's also colour->color and probably others. I find this is quite odd, considering that a lot of American pronunciation is still very close to Elizabethan English, or so I was told by a West Virginian when we were crossing Asia, following the Hippy Trail on a truck back in the '70s. In any case it was the first English colony in America, named, I was taught, by Walter Raleigh in honour of Elizabeth 1, the Virgin Queen.

I'm not sure what you are talking about. My understanding that the various parts of the kernal all had to be linked together which make it one executable and so covered by the same GPL (btw, I believe the L stands for "license"). Separately compiled doesn't have much meaning does it? Each source file can be separately compiled if it has all the libraries available. It is the linking that makes it something useful by connecting them all together.

Heck, I have a Sony video box which has a GPL license if you dig into the menus enough. Yes, they have applications running that are proprietary, but the OS kernel is fully GPL so they will give you the source if you want it.

Not the drivers. Those are real time loadable and unloadable

You will compile them with the current kernel headers but they are never statically linked.

A minimal linux install is a kernel compiled for your hardware, drivers compiled for your hardware, and something like bash to execute basic conmmands.

Some of us have evolved since then.

Whereas a lot of Essex English is still very close to neanderthal.

Judging by some radio interviews I've heard recently, the correct term is 'devolved'. At least Elizabethan pronunciation was clear and easily understood.

We know that because someone found an Elizabethan tape recorder.

They can be, and often are. For example, you kinda need your storage driver compiled in before you can reach any loadable modules.

Tends to be those things with a static footprint (the hardware never changes) have them compiled in because it saves storage which is handy when you have 4MB of flash. Larger systems, or those with dynamic storage (eMMC, USB, etc) are more likely to use modules.

The latter is often busybox. However you don't need that - you can just run your app as init(1) if necessary.

Theo

Actually, most "distribution" PC versions of Linux use a special RAMdisk which is loaded from a file by the bootloader and has the modules required for the storage access. That way all the drivers can be modules, and users who don't own the devices don't need to have these drivers in memory (as they are when they are statically linked)

The installer figures out what modules are required to boot the system on the target device, and creates a special RAMdisk image which is stored in the /boot directory as /boot/initrd.

True, when you have a baseline hardware like the Raspberry Pi or similar systems (including embedded systems) it is often better to statically link the drivers. Except when you don't want to do that for license reasons.

With an original recording of Ron Goodwin's Elizabethan serenade :)

As usual YDNRC!

You only have to make your source and any build scripts etc. available if you **distribute** anything that uses modified GPL code. You can change it for your own private or internal company use and you don't need to do jack.

Putting it on a device & selling it is distributing

as it happens TomTom do make the sourcecode for the Linux kernel they use available

this does not stop them using non GPL binary Blobs for proprietary drivers (i the same way Nvidia make binary drivers available without releasing the source code)

forgot the link