We have a project in which the SOC has multi-core like ARM Cortex-R8; so we want an open-source RTOS that supports SMP scheduling. But it seems that no RTOS supports SMP, at least from its official release version.
Could anyone give the suggestion about it?
It is neither true that no RTOS has SMP support, or even that no open-source RTOS has support.
The open-source eCOS supports SMP (Symmetric Multiprocessing). http://ecos.sourceware.org/docs-3.0/ref/kernel-smp.html
Also NuttX http://nuttx.org/doku.php?id=wiki:nxinternal:smp
In the non open-source world, choices are wider, such as QNX Neutrino, and VxWorks.
Related
Hello Humble Stackoverflow users,
According to this XEN article, PVH mode keeps all components paravirtualized except Pagetables - "but instead of requiring PV MMU (often called paravirtualized page tables), it uses the HVM hardware extensions to virtualize the pagetables".
Accoring to link i've provided above and wiki, you can learn that Pagetables are heavily connected with CPU workflow. However, following article sais that HVM hardware Extensions are providing CPU virtualization - "Technically speaking, HVM refers to a set of extensions that make it much simpler to virtualize one component: the processor."
At the end all this left me in confused state.
Does XEN PVH mode requires Intel VT-x or AMD-V HW virtualization or not?
Regards,
Leshcat
pvh only works with intel vt for now and there is no support for 32bit guests yet, as you can see in the readme
http://xenbits.xen.org/docs/unstable/misc/pvh-readme.txt
Following remain to be done for PVH: AMD port.
https://blog.xenproject.org/2015/01/15/less-is-more-in-the-new-xen-project-4-5-release/
PVH initial domain support for Intel has been added and now supports running as dom0 and FreeBSD with Linux platforms
There's a number of projects that produce complete images from your app, bootable on xen as a machine. For example Erlang on Xen, OpenMirage, HaLVM, and others.
Why is Xen the default hypervisor for them? Does it provide some interface that makes these projects easier (as opposed to KVM, VmWare, etc.), or is it just the project developers' choice?
Are Cloud Operating Systems the Next Big Thing? gives the following answer:
Xen’s footprint in the Cloud: with AWS, Rackspace Public Cloud and many others running Xen, supporting Xen first makes sense.
Xen Paravirtualization provides a very simple and idealized interface for I/O to the guest. In contrast, the KVM VIRTIO interface looks pretty much like the underlying hardware. As a consequence, it is easier to port a language runtime to Xen.
Are there any major differences between a modern Linux and QNX Neutrino that would make porting an existing client/server difficult? The source is normally built using Qt's qmake, but has no other Qt dependencies.
I need to provide an estimate for how long this process will take, but I've never used QNX.
If it matters, this will run on an ARM CPU, but we already build for ARM on Linux as well.
It's really going to be hard to estimate until you try because there are a lot of similarities, but where there are differences can be more problematic. If I were estimating, I would start by downloading an eval copy of the QNX and try building to see what problems you are facing.
The biggest issue may have is if you are using a GUI. QNX uses it's own GUI technology which is not X. (Although Qt 4.7 has been ported to QNX 6.5, so if you were to use Qt, it would probably work.)
I'm reading an article about Xen, a virtual machine monitor. They say that an operating system requires some modification in order to be able to act as a guest OS on top of Xen. Now, for an OS like Linux, I can understand what a "modification" might mean but in the case of an OS like say, Windows XP, what does it mean? I mean, XP is closed source proprietary OS right?
It means exactly the same thing. It's just harder because the source is not widely available. Note that the modifications are no longer required when Xen is used in conjunction with hardware virtualization.
Xen was originally a university project. As a researcher (or as a government agency tasked with infrastructure security), you can get the Windows sourcecode from Microsoft. You're just not allowed to distribute your own version of Windows.
This is exactly what they did: they had the sourcecode of Windows XP and then they ported XP to Xen, just to show that if Microsoft were ever to officially support Xen, it would be doable.
On the other hand, although para-virtualization cannot provide an end-to-end virtualization solution, it can improve performance.
I m trying to understand the concepts in Virtualization. I guess getting my feet wet with some free ware products would be a wise move. Any pointers and suggestions on this will be appreciated
VMWare has several free products available here. Microsoft also has some free options you should check out. Just set up a virtual machine and start messing with it.
Sun's VirtualBox is an open source virtualization product, which is a great way to get started.
VirtualBox is a powerful x86 virtualization product for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers, it is also the only professional solution that is freely available as Open Source Software under the terms of the GNU General Public License (GPL).
Presently, VirtualBox runs on Windows, Linux, Macintosh and OpenSolaris hosts and supports a large number of guest operating systems including but not limited to Windows (NT 4.0, 2000, XP, Server 2003, Vista, Windows 7), DOS/Windows 3.x, Linux (2.4 and 2.6), Solaris and OpenSolaris, and OpenBSD.