We are trying to support Java enviroment on our embedded platform (700 MHz MIPS 74K, 128-256 MB memory). After reading this article and googling a bit, I came up with the shorted list:
Java ME from Sun
Kaffe
Jbed
Perc
HP Chai VM
PhoneME - seems the most promising one
IBM WEME (Thanks to Thorbjørn Ravn Andersen)
Aplix JBlend (Thanks to QuickRecipesOnSymbian)
I was quite new to Java and its runtime enviroment. What do you recommend for a Java VM running on MIPS 74K?
You might want to look into Aplix JBlend and at a similar Stack Overflow question, "What Java embedded VM do you suggest for ARM development?".
Related
Water meter (CPU meter) does not work on my Windows standalone h2o instance. It shows "not linux" message.
Using version h2o-3.10.4.6 of h2o on Windows 8.1.
Was the feature not yet implemented for Windows deployments or is there another thing i need to consider?
Thanks!
Water Meter is only implemented for Linux systems (by reading /proc/stat data), it won't work on neither Windows nor MacOS. From what I recall we don't have anyone working on a Windows/Mac version so if you're feel like it then you can contribute, you can check the source code here and the Linux implementation here. The tricky part is that it has to use open libraries (due to licensing).
When I search about linux kernel, I know that linux support for SMP architecture.
But I don't find any specification about the linux for AMP.
Does linux support for AMP?
Have any documents or specification for descripting about that?
Anyone help?
Linux has the remoteproc subsystem and the closely tied virtio and rpmsg. remoteproc can be use to boot up a firmware blob on the remote core and the communicated with it using rpmsg. Examples of such processors include iMX7 and Vybrid. Vybrid has a Cortex A5 and Cortex M4.
See the documentation on remoteproc. ARM's big.Little might also interest you.
Yes. AMP precedes SMP, and both techs precede Linux.
Asymmetric multi processing was used when 2 Pentium II 33MhZ processors ran in parallel on the same motherboard.
It's an old Operating System, that is still supported in the current Linux kernel, and is in fact getting a face lift since cloud computing (which is essentially the same concept as AMP, but across a network instead of across a motherboard.
There's no recent talks about AMP around Linux devs, but just ask some of the cloud devs they'll talk your ears off about AMP.
This may be a foolish question but I've been searching around for some time and don't see a clear answer. I've seen several microcontrollers advertised as running Unix-like software (Linux, Ubuntu) for example, the BeagleBone Black and Arduino Yun. Can someone please explain to me the benefit of this? So far I've used a couple of microcontrollers like the Arduino Uno/Duo, Freescale FRDM and STM32 Discovery which either didn't have this feature or I was not aware of it. I'm starting to see it more and more on newer microcontrollers so I'd like to know what it brings to the table.
Full disclosure: I've had minimal exposure to UNIX and its variants so far so please talk slowly and use small words =)
Hope to hear from you,
Yusif Nurizade
You get complex drivers already included Linux for free (USB, internet protocols, storage media and file systems).
You can use lots of free software for the things not included in the kernel.
It is simpler to develop software on a full OS (easier to debug, look what is going on, change the configuration, etc etc).
The drawback is that the real-time capabilities are generally worse than for some small RTOS, and it needs more resources (a couple of megabytes memory).
In the heart of all Android and iphone is a Embedded Linux System. Without getting too deep
Linux + Java = Android
BSD Unix variant + C/C++/Object C = iOS
Now if you get deeper the above two statement can be argued for accuracy
All Android devices run on ARM based microprocessors. Beaglebone is one such open source hardware platform with can run Android as well as Embedded Linux distribution and even a Ubuntu.
Now (IMHO) Ubuntu is primarily for desktop and server application. Many of the popular computer server farms uses Ubuntu.
Now STM32 is a ARM based CORTEX-M micro control. Once again (IMHO) is mostly used for bare metal embedded applications. I have hard that FreeRTOS can be ported to TM4C123 ARM Cortex-M TM4C123.
Now the advantages of using Linux base micro controller architecture are
OS is free for the most part
Larger community of users
The industry is moving towards open source
Lot of free resources get up to speed
Disadvantage are
Learning curve is pretty steep
Expect to stumble and fall a few time
Below to two good resources to learn Beaglebone open source development
Beaglebone
Introduction to Beaglebone development by Derek Molloy of Dublin City University
HTH and good luck
I am new to linux programming & interested to tweak linux kernel(though I am not sure, what to tweak, I am planning to write drivers for particular device). To learn internal of kernel, I have started from historic kernel release (first release).
My problem is, how to test whatever changes I am doing for development, without disturbing my current os environment.(ubuntu 12, 64 bit). Is there any way like virtual box, sandbox?
Along with these, if anybody send some good approaches to learn these things, I would be really greatful.
Thank You.
If you're new to linux programming then you really don't want to be tweaking the kernel. You really want to be an advanced programmer capable of programming drivers and complex software first.
But yes there is, you can can create a virtual machine using openbox or vmware. If you're really keen on tweaking the kernel you probably want to first just try compiling and configuring the kernel and seeing if that works.
Also make sure you're well acquainted with how the kernel works and advanced OS designs in general.
Search in google fr "Kernel configuration" you u will get many links how to configure your own kernel.
And one more thing do not use a outdated version of kernel ,always use latest stable release , because a lot of code and API is changed in new versions and no book in market is updated so ,, u have to read from kernel documentation. Thats the best way to learn the most updated information about linux kernel
Yes, you can test your changes on any of the commonly available virtual machines (VMs); that way, whatever changes you make to the VM kernel won't affect native OS.
Personally, I prefer using CentOS 64 bit on VMWare Player. With this setup, I got away with minimal system maintenance while was able to focus on the actual job at hand. Once the VM is up & running, you can download and compile one of the latest stable releases from kernel.org. Instructions on compiling your downloaded version of kernel could be found here and here; however, this may require little tweaking based on your actual setup. Once the VM is running on your desired version of kernel, using a combination of cscope and ctags will help you immensely in kernel code browsing.
Finally, if you want to become a serious kernel programmer and write your own device drivers, you need to get familiar with it in the first place. Below are a few excellent references -
Linux Device Driver by Corbet, Rubini, Kroah-Hartman, 3rd edition
Linux Kernel Development by Robert Love, 3rd edition
Understanding the Linux Kernel by Bovet, Cesati
Linux kernel source (ideally placed into your /usr/src/$(DESIRED_KERNEL) path, symlinked to /usr/src/linux)
Going through these books is a tedious job and chances are that you may hit the roadblock from time to time. kernelnewbies mailing list and StackOverflow are some of the few reliable places where people would be happy to answer to your queries.
Good luck!
I will have (maybe) to work soon on ARM platform hosting a linux distribution (I don't know which distribution ..).
I know the project concerns video streaming, but I can't tell you more. Actually I only received the announe, and meet nobody yet.
I've never worked on such platform. So the idea for me is to test before the project starts.
What would you advise me to undestand how works such platform ? Internet links? Tutorials? Tools
Morevover, as I don't have any ARM processor at home (well only my iPhone ..) Which virtual machine would you advise me? (I clearly don't want to lose time installing and testing every one of them.)
I am aware of this page on wikipedia. Which one is the more appropriate running on a MacOS X 10.5/intel platform? Which linux distribution to install on the virtual machine?
I know the topic is quite wide, so any idea is welcomed! :-)
For a virtual machine that can emulate a ARM platform try QEMU. You can install a ARM-based Debian Linux distribution and tinker around with it. A google search on ARM, QEMU and Debian will get you started.
Also: Don't worry to much about the ARM CPU. You will use linux, so all the low-level stuff is already done for you. It's much more important to learn how the linux boot process works. How to install stuff ect. You will rarely (if ever) notice that you're running on a ARM device. The big difference to a PC running linux is, that the ARM will be a lot slower.
If you're looking for a real piece of hardware to play around with I suggest that you take a look at the beagleboard (www.beagleboard.org). It's cheap (around $150) and runs (among other things) various linux distributions.
With the beagleboard you'll get the whole linux cross compilation experience if you want (be warned: you'll pull your hair out).
I can't answer all of your questions, but there's a full port of Debian GNU/Linux on ARM. Works fabulously in my experience (I've tried it on a QNAP). Everything that's available in Debian works on QNAP now! So it's probably easiest to first try Debian tools and packages that come close to your project, and then continue from there.