[Fremantle] Android inside chroot
 

This thread is continuation from brainstorming about chrooted-Android in this thread. So:

what?: the idea is the same (well, maybe a little different but still quite simmilar :)) as what easy-debian is doing with Debian, just with Android.
tl;dr: Android apps on Maemo!

why?: in order to run Android apps (.APKs) in the same way easy-debian is "emulating" (this is not emulation at all) apps from it's repos.
tl;dr: Because of Android apps?

how?: first of all we need chrooted (or "LXCded") Android (NITDroid probably, or some "cropped" version of it). Steps (aka TODO):

• Patch Maemo kernel with Android features / modules. [WIP]
• Compile LXC for Fremantle.
• Make Android run inside LXC.
• Modify pakesson's ParallelDroid, so it will render Android apps to the Maemo window.
• Profit!

<- tl;dr version for this not avaible..

So far, everything up to here, was done by thp. Also, liar has made some progress in this area (on Harmattan, as thp).

Chroid is simmilar project for WebOS.
Most promising is ParallelDroid by pakesson. -- GitHub.
(Thanks Hurrian for mentioning this!)

Progress:

• I'm trying to contact alex from N900 NITDroid dev team, because the N15 link provided by him is down. I recommend to wait, as N15 is really interesting, and seem to provide many interesting features, bugfixes etc. <- there were bugs inside N15. Let's use N14 for now, later upgrade to N15 will probably not broke anything.

• Wicket suggested use of LXC insted of chroot.
• Android was already booted inside LXC (we can drop the qemulating part as we are already on ARM device).
  -- older thread about Android in LXC

I will update continually this thread / post with more info. Expect lot of problems, bugs & glitches soon! :)
Also feel free to ask, answer and share your thoughts.

(If you want to test - there is nothing to test as of now, but if you want to develop, install scratchbox & grab a copy of NITDroid. And Go!)

Re: [Fremantle] Android inside chroot
 

doesn't android require a not-really-linux kernel? (or am I still living in the past?)

if so, this would require adapting fremantle first to run on android kernels.

Re: [Fremantle] Android inside chroot
 

Wow, how much I've missed NITDroid... If this will work it will be really cool! :)

Re: [Fremantle] Android inside chroot
 

Well, as we are not trying to "run" Android itself, just chroot inside him, so it will look like Android for it's apps & services, is some kernel-work really needed?

In easy-debian, the Maemo kernel is still used & so is in chrooted-BackTrack etc. Also thp's procedure isn't saying anything about kernel-moding.

Is Dalvik somehow connected to specific features of Android kernel?

Re: [Fremantle] Android inside chroot
 

Well, look at it this way: why does Android use a non-Linux kernel? If it wasn't really necessary, why do they do it?

(hint: power management in Android is so FUBAR that they actually need this kernel "tweaks").

Well thank $DEITY Maemo is, contrary to Android, still good-old Linux. It may not be upstream, but Maemo runs on Linux (as in "kernel") and Linux (as in "distribution") runs on Maemo-kernel.

Android is not a Linux distribution.

I don't know (nor do I care, just I don't care for crippling a phone with Android).

But if you're initiating this project, perhaps you should investigate this :)

Re: [Fremantle] Android inside chroot
 

Maybe it's better to run it inside VM. I heard that Xen got ARM support.

Re: [Fremantle] Android inside chroot
 

If we are talking about N900, VM with Android is sci-fi because of performance.

Re: [Fremantle] Android inside chroot
 

This is exactly what you want to do.

Some talking points:

• There is already an Android kernel adaptation for N900
• Fremantle uses GTK
• You can do exactly what he did, on ARM

Re: [Fremantle] Android inside chroot
 

Yes!

I've seen a comment about paralleldroid by thp on his blog.
Thanks!

Re: [Fremantle] Android inside chroot
 

Quote from the linked page: "You’ll need a kernel with the Android patches (binder, ashmem, logger etc.)"

You say there is an "Android kernel adaptation for N900". I take that to mean you can run Android on the N900 natively (Nitdroid, I guess).

However the goal of this project is Android running inside Fremantle.
Neither Fremantle will run on Android kernel nor Android will run on Fremantle kernel.

I think that sorta sums it up good enough.

Re: [Fremantle] Android inside chroot
 

Note:

This (http://whiteboard.ping.se/Android/Debian) = running Android system on a Debian chroot itself running on Android kernel might be something cool to do on our N900s (or a laptop, or whatever).

Re: [Fremantle] Android inside chroot
 

http://logs.nslu2-linux.org/livelogs...o.20131109.txt

< list of Android drivers needed anyone / anywhere?

Including them in kernel-power is no-go, but what about hybrid of nitdroid-kernel and kp.
nitdroid-kernel is on Gitorious.

From here: binder, ashmem, pmem, logger, wakelocks, oom handling?

Re: [Fremantle] Android inside chroot
 

If you need an Android-kernel on which no Linux will run, then how can you run Android apps on Jolla?

Re: [Fremantle] Android inside chroot
 

Android uses a fork of the Linux kernel. It's still very much a Linux kernel and many of their changes have been accepted upstream so things have improved in this regard. Of course the N900 kernel (stock and power) are too old and do not include these upstream changes but freemangordon, pali and others have recent kernels booting on the N900 (not yet complete) so this would be a good starting point for running Android and should require fewer patches.

Xen on ARM is still experimental but you can forget about running a Xen VM of Android on the N900 with only 256MB RAM.

A more elegant option than your bog-standard chroot would be to use LXC (which has been described as a "chroot on steroids"). LXC "boots" the OS inside the chroot so you're more likely to have an environment that resembles a normal Android system. Your normal chroot would require many hacks to provide host OS (Maemo) components in the Android chroot. LXC already has ways of taking care of this. There has already been some success in running Android under LXC, but as the blog post says, "it really depends on what you want to do with it".

This is an interesting possibility. Perhaps this can be used in combination with LXC to display the Android container in a Maemo window.

The Jolla device uses an Android kernel which is why it suffers from crippled static power management.

Re: [Fremantle] Android inside chroot
 

Supposed there is static pm missing, what would happen while trying to run an Android app? //edit: Can't our Linux kernel take care of whole power management and our Dalvik app just let be controlled?

Re: [Fremantle] Android inside chroot
 

Is it possible to give access to hardware components (e.g. accelerometer, GPU, etc) to something in a LXC container? If so, could the nested Android have hardware acceleration? It makes Android apps so much more usable on the N900.

Re: [Fremantle] Android inside chroot
 

Correct me if I'm wrong, but yes, as we are not emulating anything. Drivers are still needed inside (and outside) the LXC, because chrooted system has no knowledge about it's HW.

Here is some stuff about direct rendering (simillar).

Re: [Fremantle] Android inside chroot
 

So basically we need to load android drivers in maemo chroot and use the maemo for chroot ,easy to tell , hard to do.
But how do you start the android kernel in chroot?
Asumed you have done that do you need to bind maemo to the android kernel&dalvik vm for installing and running the apps ? or do you need to use the full chroot , run full android and apps in that chroot?

Re: [Fremantle] Android inside chroot
 

AIUI, LXC containers share the same kernel still - see Oracle documentation on LXC

In that case your now looking at patching host kernel to enable Android, which I dare say is going to break a few things a long the way. If that's the case I'd start looking at a Sailfish approach by running libhybris, if only for the possibility of detaching MCE and co from N900 specifics to allow porting to other devices. Problem is how much RAM and performance loss your going to see.

Re: [Fremantle] Android inside chroot
 

If the container has the same kernel, does that mean it has to load two sets of drivers for everything? Or are the android drivers only loaded inside the LXC container?

Re: [Fremantle] Android inside chroot
 

and why the drivers (the camera one and others ) were patched to work in android(jolla) if they share the same kernel , i don°t think they share the same drivers , the layer + adaptation between them we need , there are more chances to make that available to n900 than to run maemo on other hardware , by the way why alien dalvik won°t run on kernels prior to 3.x.x (jolla , leaving qualcomm s**t aside) , from what I remember it was demoed on n900 , that phone was with a updated kernel? or our kernel was patched?

Re: [Fremantle] Android inside chroot
 

This is very cool - looking forward to this hack! :D

I'll be glad to test something if you will need more people.

Re: [Fremantle] Android inside chroot
 

That's a possibility but I wouldn't worry about that right now. Just get something working first.

Spot on.

Correct.

That was always going to be the situation, even with a normal chroot. It's not possible to run multiple kernels without a hypervisor.

libhybris shouldn't be needed. The kernel and drivers will be running under Maemo with glibc and will continue to talk to the hardware as normal.

The big advantage of OS-level virtualisation is that there is little or no overhead. It will only use whatever is normally used by Android.

Drivers (kernel modules) are an extension to the kernel hence they will be provided (shared) by the host OS. If there are any userspace drivers they would have to be loaded inside the container.

I'm not familiar with Android/Jolla patches and without knowing the details I can only speculate but it's possible that they were userspace drivers.

That demo was a long time ago so it would have been based on an older version of Android running a 2.6 kernel, most likely patched.

Re: [Fremantle] Android inside chroot
 

As on Harmattan, the systems runs okay enough even with Android drivers enabled and loaded - no app uses them, so they're left well alone ;)

And the same situation in reverse - on my Android device, I can stop Zygote, take control of the framebuffer, and start Xorg with the GNU Userland from a terminal.

Assuming that Android runs inside Maemo via ParallelDroid, and static PM support isn't available, Maemo's (IMO superior) dynamic power control will reign supreme.

Re: [Fremantle] Android inside chroot
 

so , let"s start with kernel , what patches and how to compile them without breaking maemo?

Re: [Fremantle] Android inside chroot
 

Can't Maemo run on the Nitdroid kernel? If so, that would be a good place to look.

Re: [Fremantle] Android inside chroot
 

I'd say help freemangordon, pali, et al. to run maemo on 3.x kernels, then go from there.
Win-win for everyone.

Re: [Fremantle] Android inside chroot
 

Well, I was trying to compile LXC and when generating configure by running ./autogen.sh I'm getting:

aclocal: configure.ac: 205: macro `AM_COND_IF' not found in library
aclocal: configure.ac: 219: macro `AM_COND_IF' not found in library
aclocal: configure.ac: 234: macro `AM_COND_IF' not found in library
aclocal: configure.ac: 252: macro `AM_COND_IF' not found in library
aclocal: configure.ac: 269: macro `AM_COND_IF' not found in library
aclocal: configure.ac: 304: macro `AM_COND_IF' not found in library
aclocal: configure.ac: 315: macro `AM_COND_IF' not found in library
aclocal: configure.ac: 377: macro `AM_COND_IF' not found in library


That's probably related to old version of autoconf used in scratchox. Will update & report.

<- solved by downloading .tar.gz tarball & running configure directly.

Another error log, when running make:

In file included from lxc_attach.c:37:
utils.h:56: error: static declaration of 'setns' follows non-static declaration
/usr/include/bits/sched.h:91: error: previous declaration of 'setns' was here

Ideas? <- caused by broken version of libc6 from previous projects. Reinstalling whole scratchbox, will let you know soon :)

#lexik

Re: [Fremantle] Android inside chroot
 

So what's this whole kernel discussion for? This would mean we don't need those static PM patches... And lexik, don't get scared by any "It won't work" posts. The same was said about Harmattan, that Harmattan apps won't work on Fremantle (hard/soft float)

Re: [Fremantle] Android inside chroot
 

that it°s a longshoot , it should be more easy to apply to our kernel instead of the 3.x.x one due to missing drivers in the last one

Re: [Fremantle] Android inside chroot
 

The first thing you’ll need if you want to do this is get your machine to run an Android kernel, you’ll need to have any modules needed by Android built and loaded before you can start the container.

The Android kernel, is not necessary, if we will have the kernel modules (.ko) compiled & loaded, I guess. I'm going to test it first on my x86 machine.

Re: [Fremantle] Android inside chroot
 

the nitdroid modules need to be recompiled(or the maemo kernel) , you can°t load maemo modules in nitdroid kernel (tried that) , loading nitdroid modules in maemo i didn°t try yet

Re: [Fremantle] Android inside chroot
 

loading nitdroid modules in maemo i didn°t try yet

That's what I want to try :)
What's the specific problem in loading fremantle modules & drivers into Nitdroid?

Re: [Fremantle] Android inside chroot
 

i didn°t remember the output , that was long time ago, install nitdroid and try to load modules , replacing or renaming them

Re: [Fremantle] Android inside chroot
 

Why do we need those Android kernel modules, if our dynamic pm can rule supreme?

Re: [Fremantle] Android inside chroot
 

we need that for dalvik , not all of them , pm-power management?
or maybe libdvm.so for maemo + other changes ?:confused:

Re: [Fremantle] Android inside chroot
 

Dalvik links against kernel modules? So how would have thp launched a Dalvik hello world without Android kernel modules?

Yes, pm = power management.

Re: [Fremantle] Android inside chroot
 

if you show-me a complex app runed by thp I will agree with you

Re: [Fremantle] Android inside chroot
 

I can't point such an app :)
Won't an error message be shown if a kernel module is missing?

Re: [Fremantle] Android inside chroot
 

compiling a module for each app isn°t the road ,and the games runned by apkenv aren°t dalvik apps , even those are using nitdroid modules , not maemo ones