MHL and Android - General Questions and Answers

I really need a developers answer to this question as this is a very technical one.
Ever since I've seen Ubuntu's site about Ubuntu on Android, I've wanted to do the same concept on my phone. I want to be able to do it myself as I've had experience with working with Gentoo and Arch but unfortunately not as deep of an understanding of how xorg and the kernel relate to each other (other than knowing xorg loads kernel modules and sets up the display) but understood that the Android OS has it's own display mechanism for creating things on the screen.
I'm also guessing that MHL (the tech behind the microUSB to HDMI) is a module of it's own as not all Android devices have access to doing this. If it's a module, I'm also guessing it's got it's own display driver which might be separate from the Android OS.
The root of my question is, would it theoretically be possible to get an xserver running off of that device for a chroot linux os so we can have a native linux on the phone when plugged into a MHL adapter? I am also guessing that I could script a chroot environment to start when the phone starts and maybe run a script on a hotplug from the MHL device to run the xserver... or if it works this way, have it running and it just needs a display show? Maybe an app to swap from linux to android display on the output through the phone? Would be a nice thing to have for us. Imagine being able to just work directly on the device through linux on the same device without using vnc.
I don't know if the Android OS display server (don't know what it's called) takes over all display devices and if that's why it's a problem or what the technical hurdles are, maybe that's another question that could be answered for me please?
I feel like I'm going to get a search the forums answer to this but I am searching, just hard to find answers to some of these questions since it's not the typical "I want wifi calling." or "I want (insert feature here)." or even "How does (insert feature here) work?"
This would be my first steps into developing, and I'm willing to take the time to learn, just would like a nice push in the right direction as to what the hurdles are and where I need to go for answers. Thank you in advance. =)

You may want to try the xda irc and look for linuxonandroid. You'll probably get much better answers than in q&a.
Sent from my M886 using Tapatalk 2

I am also interested in MHL support.
If you find any info please post it here too.

Related

ndk touchscreen events

This is probably somewhat of a linux question rather than an ndk question, but I'll ask anyway. Anybody know how to read the low level touchscreen events? I'm still a noob with the low level linux device coding. I've done some successful hacking of this and that, but sort of need some example code.
Ideally I'm hoping there's an input file that's relatively filtered, so you can read x/y points from it directly (or something like that). So far I've found /dev/eventX to point to the synaptics touchscreen, but I have no idea what would be the next step with that, and I assume that's going to be very raw data coming in.
Any thoughts? On the Java end, the best I could find was dispatchTouchEvent in the Activity class. To get at a lower level of inupt, the next step would really be building a custom OS build (I guess. There's probably something far easier that I'm not aware of).
I also may try to backtrack through the android source to see how the system dispatches its calls. It has to be there, but as of now I can't find it.
Thanks in advance.

PC emulation on Android - OS XDA project links.

So in this thread it tells you how to install pc operating systems like windows and linux on the Evo 3D.
http://forum.xda-developers.com/showthread.php?t=1459153
This, is freaking awesome. This one is a big breakthrough.
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Here is the thread in the Nook Color forums for ubuntu on the device:
http://forum.xda-developers.com/showthread.php?t=1055954
----
These two threads are native installs, not using some client to access the installation, the device itself is the client as it should be.
This is not some chrooted virtual OS simulation, but the real deal installed to the device.
----
In the back of my mind i've wanted to play with ubuntu installed on the MT4GS, but not a virtual installation I want it installed and running on the device natively.
I definitely don't have the time to do this and a lot i'm trying to do around here even if I wasn't in my busy season for work.
Dropping this information so I can find it later when I do get to trying to get ubuntu (and now windows XP looks like a possibility) installed on this device.
If anyone else feels like looking into this, here's a good place to start. If anyone comes across any other projects that are the real deal and not virtual installs please post links here.
Have fun!
Blue6IX said:
So in this thread it tells you how to install pc operating systems like windows and linux on the Evo 3D.
http://forum.xda-developers.com/showthread.php?t=1459153
This, is freaking awesome. This one is a big breakthrough.
----
Here is the thread in the Nook Color forums for ubuntu on the device:
http://forum.xda-developers.com/showthread.php?t=1055954
----
These two threads are native installs, not using some client to access the installation, the device itself is the client as it should be.
This is not some chrooted virtual OS simulation, but the real deal installed to the device.
----
In the back of my mind i've wanted to play with ubuntu installed on the MT4GS, but not a virtual installation I want it installed and running on the device natively.
I definitely don't have the time to do this and a lot i'm trying to do around here even if I wasn't in my busy season for work.
Dropping this information so I can find it later when I do get to trying to get ubuntu (and now windows XP looks like a possibility) installed on this device.
If anyone else feels like looking into this, here's a good place to start. If anyone comes across any other projects that are the real deal and not virtual installs please post links here.
Have fun!
Click to expand...
Click to collapse
Regardless of what impression you may have, it is ABSOLUTELY IMPOSSIBLE to run MSWin on ARM hardware natively. The reason for this is that MSWin is x86 and ARM is... ARM. The approach used in the first link is to use BOCHS (pronounced "Box"), which is a VIRTUAL HARDWARE EMULATOR. It requires a host operating system to be functioning in the background, in this case Linux.
As for Ubuntu... well sure. No problem. Its Linux and the phone runs Linux. Not that big of a stretch to replace the Android parts with GNU.
Note that NONE of this is any kind of "great breakthrough". Bochs has been around for a VERY long time. First OPEN SOURCED in early 2000. Yeah, 12 years ago. As for Ubuntu... well I suppose that the main reason that most people aren't making a native android replacement out of ubuntu, is that not many people are all that interested in it. Cute in theory, but not practical.
What would be a more worthy project would be to upgrade android to GNU libraries and utilities. This would afford us an actually USEFUL balance between the two. Also the ability to run X *through* android without having to do stupid things like VNC. Have the proper interface ***AS AN ANDROID APPLICATION***, leaving Android to work (i.e., phone calls, etc.) while simultaneously offering the standard Linux applications.
My thought though, is that this is becoming less and less important. Firefox is on Android now, the Document foundation has announced LibreOffice for Android -- supposed to be by late 2012 to early 2013... GIMP has no place on Android... That certainly covers the basics.
Appreciate the post. I didn't have time to dig into it too deeply, so took it at face value for the impression I got. Happened to come across it in passing and didn't want to lose track of something vital to the future dev of a project like this on the doubleshot. (but definitely this doesn't belong in the dev section at this time - just clutter there.)
I was hoping people would add to it, especially the way you have, who had more of an understanding of what's going on there - I didn't realize that it was a virtual environment for the windows stuff, but it did seem to good to be true.
Even if no one responded I figured the thread would get pushed down out of the way, but still be here when I got the time to come back to it.
----
My reason for running native linux on the device itself is to be able to use the Android SDK and tools without needing a computer to do so. I have 2 of these phones and a Nook Color. The NC has USB host support, so I could plug the doubleshot into it without frying either device. (yes, i'm blending android and linux concepts here - but usb host support in android shows that it's capable of doing it)
Even from one doubleshot to the other I could use wifi adb for a lot of stuff without plugging them into each other through USB and frying the phones. So that would be a victory as well.
The lack of a hardware charging circuit in the doubleshot makes the worry of frying the phones a big deal, power transfer through USB is a big hurdle to jump in management.
Beyond that - the doubleshot is powerful enough on hardware specs to be able to compile a kernel, but that's not gonna happen through a virtual linux install because the overhead is too much. A native install might just be able to do it though. Won't know until I try, but it's worth the work to get to the point of trying, even if it doesn't work out.
The Nook Color probably won't be able to compile a kernel - it's asking too much from a device not really able to handle that.
Getting what I mentioned above to work would mean I could do all my dev work with what fits in my pocket, and let me keep working wherever I am.
I do like the idea of an app to work with this through Android itself - but I don't see how I could use the SDk and variety of user-created tools without a native linux install. Worth pursuing either way though.
If anyone has anything to add, i'd be welcome to hear it. Just understand this is not a project i'm working on or actively pursuing right now - but fully intend to down the line.
Actually blue. There is a thread somewhere that has a step by step on installing ubuntu on gingerbread. I meant to add it when I added the backtrack link. For some reason I didn't, I probably forgot, I actually think the link for it is in the backtrack thread in the sticky.
If I do find it ill let you know.
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[Q] Install Linux on Kindle Fire?

I'v read some post on about install Linux distribution(Ubuntu, Arch Linux ARM, Gentoo) into a tablet pc, and I wonder if I can install Linux on Kindle Fire... I've no idea about this kind of thing, so if you think it's possible, I'll learn how to do it... Thank you in advance...
I Think if Kindle fire run on linux arm kernel you can. but you must porting Ubuntu's package to ARM and install this. But It is not so easy and can make problem to device
What about extending, not replacing, android linux?
Shouldn't it be possible to add commands to the Linux that underlies android to give it the functionality of at least some version of full Linux while keeping the android layer on top of it? I'm not a developer, so I don't know what all the technical problems might be, beyond the following:
Some kind of compiler is necessary, but isn't that also needed to create an android ROM anyway?
Code:
Since the KF doesn't accept an SD card, space might be a problem, but maybe a USB memory stick (flash drive), an OTG adapter, and perhaps some change to the bootloader to allow the KF to go into USB host mode might work. And the solution would probably be easier if the external memory were used for data and apps, but not for any part of the OS?
Perhaps this discussion belongs under Android Development, either specifically for the KF1 otter or more generally. Maybe there already are such discussions on xda or elsewhere. Guidance from developers and others in the know would be appreciated.
This sounds like a Decent idea. I actually want to try that now.

[Q] USB WIFI capability

Hello all!
Firstly, I would like to thank many people for their inputs on this site. I have been viewing it for quite some time, so I finally created an account. I cant wait to get in the community!
Now, as for the reason for this post. I am trying to get my ALFA USB WiFi AWUS036NHA to work with my Tab 2 7.0. After doing some research I am with the understanding that I must write the drivers into the kernel. I have a decent understanding of how the kernel works with the hardware and software of the device (the theory of it, rather), but I do not know how to actually edit the kernel. I have done some software developing on Linux, Windows, iOS, and the PSP-1000 communities, but I did nothing with their kernels.
My question is, is there a pre-built kernel with the RALINK drivers? If so, I would love a link to that, but I am also interested in learning how to modify the kernel, for I am mainly a Linux/Android fanatic.
Any input would be appreciated,
Thanks!
Edit : Just for informational purposes, my tablet is on Cyanogenmod 4.2.2. The only thing on it are a BlackUbuntu image, and a Backtrack 5 image, which I boot through terminal.
Edit : I am currently setting up the Eclipse IDE on my Ubuntu system. I should be ready to go by morning. I have been reading references and studying source code for the better part of the day.
Azraelpwnz

Creating a linux 'distro' for an android device?

Hi there, not sure if I'm on the right forum, but this seemed like the safest place to ask.
I have this project in my head that I would like to try, but I have no idea if it is even possible.
I'm currently doing a bachelors in computer science and as a way to learn, I would like to take on a big project.
As will soon become clear, I am a linux noob and know nothing about android development, but that's what I'm trying to change here.
Some time ago I bought a Chinese ereader (rebranded BOOX C67ML - using a rockchip rk3026 SoC, don't know how important that is -) and it's decent but it also kind of sucks. It runs android which overkill for a device like this if you ask me. When I look at the kindle or kobo ereaders, they have their proprietary os that is also Linux based, but much more streamlined without unnecessary features. This device doesn't even have wifi, so what am I going to do with full android on an e-ink screen? It only drains my battery more than it has to.
My question is, how feasible is it to create my own 'OS' for this device that is also Linux based and lightweight? I know that android devices can run gnu/linux in a sort of vm on top, but is it also possible to install this directly on the device? Wipe android and install a custom linux distro as you would a custom ROM.
Is this possible? Where do I begin? Any information on how the linux kernel underneath android functions and differs from a standard linux kernel would be great. I'm not asking for an easy solution served on a platter, I just want to know if it is possible and why or why not? Where do I go to learn about how to do this, point me in the right direction?
In searching around I came across postmarketOS, from what I understand they are trying to do something similar, only completely open source. No proprietary drivers for anything. For this project that is not a goal for me. If I can reuse parts of the android rom that it is running right now, I have no problem with that. Updating and keeping it up to date are not really a priority, I just need this to run a single application that works. Could also be that I completely don't understand what they are trying to do and I'm way off, but if so, please tell me what I don't understand and where I go to learn.
TLDR: Lightweight 'desktop' linux instead of android on an ereader, is it possible? Where do I start? Point me in the right direction please.
PS: If there is a better solution for this problem entirely, please do explain.
For anyone interested or with a similar idea, I'll just post what extra information I find here.
I stumbled upon Halium and Libhybris today. From what I understand, libhybris provides a compatibility layer between the android kernel and posix compatible applications. Halium uses libhybris and tries to create a common base that can be used to develop a non-android os for an android device. Please correct me if I'm wrong.

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