I'm not going to try and trim all of this on an iPad, sorry. But I want to throw my two cents in on the Android and Ubuntu are Linux variants. <br><br>Ron, I don't know what distributions you are familiar with, but I think you use Ubuntu. Try using Debian proper in a VM and see if you can spot the differences. Ubuntu is a direct "variant" of Debian, and I think you'll find that the two operating systems are _very_ different. They are both "Linux" in that they are both based on the Linux kernel from <a href="http://kernel.org">kernel.org</a>. But they are not the same operating system. <br>
<br>Another test would be to install CentOS in a VM. The difference between it and Ubuntu is not at all subtle. <br><br>On Friday, August 12, 2011, Michael B. Trausch <<a href="mailto:mike@trausch.us">mike@trausch.us</a>> wrote:<br>
> On 08/12/2011 05:15 PM, Ron Frazier wrote:<br>>> Thanks for the info. OK, the essence of what you're saying is, Android<br>>> is a variant of Linux and Ubuntu (and other similar) are variants of<br>>> Linux, but as a practical matter, they're not software compatible.<br>
><br>> Your confusion is understandable. Our community often refers to whole<br>> systems as "Linux". A lot of people in our community for years said<br>> that was a dandy term because it was unambiguous. Some have argued for<br>
> years that it is ambiguous because of the lack of understanding it<br>> yields, and today, when the Linux kernel is used in more places than<br>> most other operating system kernels, this ambiguity is coming to light.<br>
><br>> Neither Android nor Ubuntu are "Linux variants". They are both systems<br>> which are built on top of the Linux kernel. Furthermore, there are<br>> other, non-Android/Linux, non-GNU/Linux systems out there, albeit of<br>
> quite limited popularity.<br>><br>> What I have told people for years---and will continue to tell<br>> people!---is that a kernel alone does not an operating system make.<br>> Application software is designed to run on one or more "operating<br>
> systems", and from the point of view of an application program, the<br>> operating system is a standard interface that the program can use to do<br>> its work. Unfortunately, the very nature of that definition is that<br>
> there are a lot of grey areas.<br>><br>> Unfortunately, I can think of no single operating system that I can cite<br>> as a means to clarify that grey area. Much like the US federal court's<br>> opinion of obscenity, "I know what [an operating system is] when I see it."<br>
><br>> To try to help (and with the realization that this may cause even more<br>> confusion): Gentoo, Slackware, Debian, Red Hat Enterprise Linux,<br>> Ubuntu---they are all the names of operating system distributions. They<br>
> all do things differently. They all, however, serve much the same<br>> purpose, to drive our hardware and provide a platform for applications<br>> to run on top of. Much the same can be said for Microsoft Windows 7,<br>
> albeit for a much more limited selection of hardware and in some cases<br>> more applications (since it is a popular target for proprietary<br>> software, whereas most Linux systems are not, and nearly all free<br>
> software that runs on Linux-based systems is capable of running on<br>> Windows in some way or another).<br>><br>> Back in the days of Windows 9x, there was a lot of questions as to<br>> whether Windows 9x constituted an operating system or not. I tell<br>
> people that they _were_ operating systems. They essentially used MS-DOS<br>> as a bootstrap, and attempted to provide a large degree of backwards<br>> compatibility that ultimately proved to be detrimental to the Windows 9x<br>
> ecosystem. The NT-based versions of Windows were (are) the answer to<br>> that problem, where DOS is no longer something that actually is executed<br>> on the system, but is instead fully emulated in a virtual machine (on<br>
> 32-bit versions of Windows; no longer is that the case on 64-bit<br>> versions of Windows, though 64-bit versions of Linux can still run DOS<br>> programs :-)).<br>><br>> In any event, an operating system is much more than the kernel; core<br>
> libraries and system interfaces that are provided "on top of" the kernel<br>> can be considered to be part of the operating system. From the point of<br>> view of applications (as well as users), an operating system provides a<br>
> minimum set of libraries and application programs (/bin/sh, /bin/ls,<br>> etc.) with it.<br>><br>>> So,<br>>> if I get an Android tablet, I would get apps from the Android<br>>> marketplace (if supported) and independent Android websites. If I get a<br>
>> Linux tablet, I would apps from it's repositories or independent Linux<br>>> websites. The software from the one would not work on the other type of<br>>> platform unless the software specifically mentioned that it works on<br>
>> Android or Linux respectively.<br>><br>> It is possible to install Debian "on top of" Android, as well as other<br>> operating systems, such as Ubuntu. However, doing this is an incredible<br>
> task and requires a significant amount of understanding as to what it is<br>> that you're doing, and precisely why it works. You must also be sure<br>> that you have a Linux kernel that is configured to sufficiently satisfy<br>
> the requirements of both systems; for example, newer distributions that<br>> are now using systemd as an init dæmon are no longer able to work with<br>> kernel versions later than 2.6.39 (e.g., the very last 2.6 kernel),<br>
> which you won't find as the basis of Android systems yet.<br>><br>>> That brings up a couple of more questions. Hypothetically, say I get an<br>>> ARM9 Android tablet with 512 MB RAM and a 500 MHz processor. Is it<br>
>> possible to reflash it to run either Android (as designed) or a variant<br>>> of GNU/Linux, and to switch back and forth between the two, so I can do<br>>> development and testing either way. Also, I'm seeing designations of<br>
>> several types of ARM processors, such as ARM v5, ARM 9, ARM v9, etc. Do<br>>> these variations substantially affect the capabilities of the system and<br>>> is it something I need to be worried about.<br>
><br>> System requirements can be deceiving. Nobody in their right mind would<br>> run a full Ubuntu stack on hardware that was originally designed to run<br>> Android, because it would be intolerably slow; Android as a platform<br>
> defines a set of constraints that enable it to fit in a<br>> resource-constrained (rather, what we today call resource-constrained)<br>> systems. Of course, back in the day of the 8088, our modern Android<br>> gadgets would be considered to possess an almost god-like power, but<br>
> that's neither here nor there. :-)<br>><br>> That said, Android *has* been ported to run on x86/x86-64 hardware. You<br>> can run Android on a PC just fine. You can even dual boot a GNU/Linux<br>> system and Android if you so desire. Given enough motivation, you can<br>
> do just about anything that your heart desires. You could even use<br>> Dalvik on top of Ubuntu if you really wanted to, though I cannot imagine<br>> a reason that anyone would.<br>><br>> I would suggest that you do a lot of reading on what comprises a<br>
> barebones functional GNU/Linux stack (ignore extras such as X!) and what<br>> comprises a barebones functional Android stack (which includes a fair<br>> bit more than a barebones functional GNU/Linux stack, in terms of<br>
> functionality and defined programming interfaces). Look at the<br>> platforms that they run on; the bootloader, the kernel, what starts up<br>> as PID 1, the libraries that are considered to be part of the base<br>
> system, and so forth. This will significantly increase your<br>> understanding of what the systems really are, and how they can be made<br>> to interoperate without a hypervisor (if truly desired).<br>><br>
> And yes, it would be possible (in theory) to "port" Android to run in a<br>> window on an X11 display. That doesn't really make it "not an operating<br>> system", for various reasons. One operating system can be made to run<br>
> on top of another operating system, after all---especially when<br>> everything involved is either free software or open source, truly<br>> _anything_ is possible!<br>><br>> --- Mike<br>> _______________________________________________<br>
> Ale mailing list<br>> <a href="mailto:Ale@ale.org">Ale@ale.org</a><br>> <a href="http://mail.ale.org/mailman/listinfo/ale">http://mail.ale.org/mailman/listinfo/ale</a><br>> See JOBS, ANNOUNCE and SCHOOLS lists at<br>
> <a href="http://mail.ale.org/mailman/listinfo">http://mail.ale.org/mailman/listinfo</a><br>><br><br>-- <br>James Sumners<br><a href="http://james.roomfullofmirrors.com/">http://james.roomfullofmirrors.com/</a><br>
<br>"All governments suffer a recurring problem: Power attracts pathological personalities. It is not that power corrupts but that it is magnetic to the corruptible. Such people have a tendency to become drunk on violence, a condition to which they are quickly addicted."<br>
<br>Missionaria Protectiva, Text QIV (decto)<br>CH:D 59<br>