I have a short Question related to Raspberrys but in applies in general to Linux systems.
Can I prevent someone from reading out the SD-Card of the Raspberry?
What do I mean: I can simply disable all login-posibilitys to prevent anyone from logging into the system. But if you unplug the SD-Card and mount it in another linux system, you still have full access to all files.
Is there any possibility besides glueing the SD-Card to the Pi?
I would be already greatfull for some keywords to google with ;)
some Linux distributions (e.g. Ubuntu) support full disk encryption, which you can activate during setup.
Since you have an Raspberry PI, I assume that you have already installed raspbian. Therefore you can search for raspbian home folder encryption for example.
You can also set access rights so only the Pi user can open them.
i am basically asking this to minimise my OS disk space
It depends on what OS. For example, Windows installs a bunch of drivers in the hard-drive, GNU/Linux, depends on the distribuition. Some distribs, you can chose what drivers to install, besides the generic drivers.
If I install a bare-metal hypervisor (say, ESXi), would it allow me to run Windows 7 concurrently with Linux?
Would it allow me to run multiple instances of Windows 7?
When I'm sitting at the PC that's running Win7 and Linux on a hypervisor, which OS do I see when I look at the screen? (I'm suspecting that the only way to access either OS is to do a remote login.)
Assuming the answer to #2 is yes, how do you manage multiple installs of Win7 on the same hard drive?
Thanks in advance!
If you simply want to run Linux and Windows in parallel you may of course do this on e.g. ESXi. Still, the OSes would run with virtualized (or emulated) hardware available to them, i.e. you would not be able to easily access all the hardware directly and the hypervisor itself not only introduces an overhead but this overhead is not deterministic.
If you want to run an RTOS (like Real-Time Linux) or any other RTOS, then you need a "real-time hypervisor".
You can google for such hypervisors - there are a few out there.
(I dont want to recommend one here as we are a vendor of such a solution our selves)
Regards
GFL
I was wondering if there was a very simple and free virtual machine that would allow you to boot from a folder or disk image that couldn't damage my hard disk. I am using a MacBook and am looking into operating system programming. I found a tutorial on the internet that looked promising. I want to try this but using a VM instead of actually booting from a disk. If I made a folder or disk image containing the boot.bin file and wanted to try the OS I made (while booting from a folder or disk image, not a disk), is there a VM that would let me do it? I have no previous experience with virtual machines. I also want to be sure my hard disk would not be damaged.
If you can make a cdfs .ISO, any VM technology on the market today could do what you ask. VirtualBox, KVM, Xen, VMware, VMware Fusion (on the macbook), etc. Not sure if Parallels can work for you, though.
VMware's products can also boot from floppy images, which are simply binary blobs (for the most part).
On the Mac I think you're limited to VMware Fusion (maybe Parallels), but on Linux you have so many options.
virtualbox (formerly from Sun, now from Oracle) is probably the most powerful VM that you can run on all of Windows, Macs and Linux (OpenSolaris too of course;-) and is at the same time open source (and, of course, also free as in free beer). Whether it supports your new OS is not entirely certain (since it's oriented to supporting a specific list of "guest OS"s and of course your new one isn't there), but, what with it being free, it's surely worth giving it a try.
Does anyone know of a good software development framework or similar that has the following properties?
Cross platform: it should be runnable on XP, Vista, OSX and common versions of Linux (such as Ubuntu and Kubuntu).
No installation: Be able to run the software from a USB stick without having to copy anything to the host machine.
Have good GUI support (this is why this question doesn't give a suitable answer, as far as I can tell).
Permissive licensing such as LGPL or BSD or such.
Among the softer requirements are having a set of abstractions for the most common backend functionality, such as sockets, file IO, and so on (There is usually some platform specific adaptations necessary), and supporting a good language such as Python or C++, though it is usually fun to learn a new one (i.e. not perl).
I think possible candidates are Qt 4.5 or above (but IFAIK Qt software will not run on Vista without any installation(?)), some wxWidgets or maybe wxPython solution, perhaps gtkmm. The examples I have found have failed on one or another of the requirements. This does not mean that no such examples exist, it just means that I have not found any. So I was wondering if anyone out there know of any existing solutions to this?
Some clarifications;
By "framework" I mean something like Qt or gtkmm or python with a widget package.
This is about being able to run the finished product on multiple platforms, from a stick, without installation, it is not about having a portable development environment.
It is not a boot stick.
It is ok to have to build the software specifically for the different targets, if necessary.
The use case I am seeing is that you have some software that you rely on (such as project planning, administration of information, analysis tools or similar) that:
does not rely on having an internet connection being available.
is run on different host machines where it is not really ok to install anything.
is moved by a user via a physical medium (such as a USB stick).
is run on different operating systems, such as Windows, Vista, Ubuntu, OSX.
works on the same data on these different hosts (the data can be stored on the host or on the stick).
is not really restricted in how big the bundled framework is (unless it is several gigabytes, which is not really realistic).
It is also ok to have parallel installations on the stick as long as the software behaves the same and can work on the same data when run on the different targets.
A different view on the use case would be that I have five newly installed machines with Vista, XP, OSX, Ubuntu and Kubuntu respectively in front of me. I would like to, without having to install anything new on the machines, be able to run the same software from a single USB stick (meeting the above GUI requirements and so on) on each of these five machines (though, if necessary from different bundles on the stick).
Is this possible?
Edit:
I have experimented a little with a Qt app that uses some widgets and a sqlite database. It was easy to get it to work on an ubuntu dist and on osx. For windows xp and vista I had to copy QtCored4.dll, QtGuid4.dll, QtSqld4.dll and mingwm10.dll to distribution directory (this was debug code) and I copied the qsqlited4.dll to a folder named "sqldrivers" in the distribution directory.
You mention wxWidgets but dismiss it as failing at least one of the requirements.
I don't know what your requirements are and in what way wxWidgets wouldn't work for you, but IMO it does fulfill them:
Cross platform: it should be runnable on XP, Vista, OSX and common versions of Linux.
It does run on those platforms, but "common versions of Linux" isn't good enough, as you can never be sure that the necessary GUI libraries for wxGTK (which should not be linked to statically) will be installed. This is however a problem for other solutions as well, unless you plan to put everything onto the stick.
No installation: Be able to run the software from a USB stick without having to copy anything to the host machine.
See the previous point, you would need to specify which libraries are needed on Linux. Also you could specify at build time not to use some of the system-provided libraries (for example for graphics, compression, regexes) but to use the wxWidgets-internal libraries instead.
Have good GUI support
Check.
Permissive licensing such as LGPL or BSD or such.
Check. You can statically link wxWidgets into your application too.
supporting a good language such as Python or C++
Supports both, and there are bindings to other languages as well.
having a set of abstractions for the most common backend functionality, such as sockets, file IO, and so on
It does have some abstractions like that, but you can link to other cross-platform libraries as well.
We use wxWidgets for FlameRobin, a graphical administration program for the Firebird SQL server. It has active ports to Windows, Linux and Mac OS X, and has been compiled for at least some BSD variant and Solaris as well. It definitely runs from a stick on Windows, I haven't tried with Linux or Mac OS X, but I don't see why it shouldn't there too.
Java.
It has GUI support.
It provides your network/file/etc. abstractions.
It is cross-platform. Most platforms you can think of have a JRE available.
No need to install a JRE. Most users probably already have one, and if not, you can run the appropriate JRE right off the stick.
You can provide several startup scripts for various platforms to run the app under the appropriate JRE.
Something else to consider is HTML+Javascript. :D
You can look at Mono it cross platform, has GUI (GTK+, or Winforms 2.0) and I can execute code without installing.
This might not be crossplatform, but is maybe even better, it dont even use the platform : linux on a stick :-)
The subtitle is
Take your Java workspaces wherever you go on a USB key
Here with java and eclipse, but nothing stops you there of course.
http://knol.google.com/k/inderjeet-singh/installing-a-ubuntu-hardy-heron-java/1j9pj7d01g86i/2#
Well, it depends on what you mean by 'package'. Kylix came close to being such a thing. It was QT based, and it allowed you to write once and compile for Windows + Linux. However, it was not an open source solution.
I asked a similar question in this link
http://www.24hsoftware.com/DevelopersForum/CrossPlatform-C-Library.html
and the best asnswer seems to be QT.
I have started using QT, but it is not as easy as I expected mainly due to deployment problems due to the DLL hell, Winsxs hell and manifest hell.
Tclkit is a single-file, self-contained Tcl/Tk system. The mac version I have is about 3.8 megs. You can get a version for just about any modern OS. I carry around a thumb drive that has mac, windows and linux binaries so I can run my scripts on any platform. No install is required, just copy one file wherever you want.
The most recent versions of tcklit use native, themed widgets (though, on *nix there really isn't a single "native" set of widgets...)