I am trying to run an Android emulator inside a virtual machine and would like to use KVM's nested support to speed up the emulator.
I run the emulator with emulator64-x86 -avd test -qemu -m 1024 -enable-kvm and I've made sure KVM nested support is available on both host and guest: cat /sys/module/kvm_intel/parameters/nested is "Y"
Still the emulator is slow, is there something I'm missing or a log file I can consult to see if nested support is in fact used at all?
Related
I have tried to follow the instructions from Movesense on how to do Whiteboard communication using ADB. This does not work as expected.
On a sidenote - I'm just trying to set up a handful of sensors to start some heart rate and movement measurement and store data to the logbook. After 30-40 minutes, I want to stop measurements and fetch the data from each device. My first dream was that I could do this using Whiteboard over BLE (from Matlab, Python, LabVIEW, ...) without having to use ADB or similar solutions. But I guess this was a bit too optimistic.
Setup
Installed the adb tools: OK
Enabled USB debugging on an Android phone: OK
Tested that adb can install apps and handle the phone: OK
Installed sampleapp-debug-1.5.1.apk:
Tried to install using adb: OK
Tried to install by copying the file to the phone and installing it there: OK
I got a message saying that the sample app was not compiled for the current version of Android (I'm using a Samsung S10e running One UI version 4.0 and Android version 12, security fix level 01.02.2022).
Im working on an Intel Mac running Big Sur 11.6.5 with plenty of resources.
What I've tried so far
First of all, I start the app and connect to the MOVESENSE device.
When trying the example commands from Movesense, I get:
Switch on LED:
fjp#fMac-19 sensorsw % adb shell am broadcast -a android.intent.action.MOVESENSE --es type put --es path Component/Led --es value '''{\"isOn\":true}'''
Broadcasting: Intent { act=android.intent.action.MOVESENSE flg=0x400000 (has extras) }
Broadcast completed: result=0
Get Info
Get Info does only work if I place curly braces between the quotas. See results below for both variants.
fjp#fMac-19 sensorsw % adb shell am broadcast -a android.intent.action.MOVESENSE --es type get --es path Info --es value ''''''
Exception occurred while executing 'broadcast':
java.lang.IllegalArgumentException: Argument expected after "value"
at com.android.modules.utils.BasicShellCommandHandler.getNextArgRequired(BasicShellCommandHandler.java:295)
at android.content.Intent.parseCommandArgs(Intent.java:8329)
at com.android.server.am.ActivityManagerShellCommand.makeIntent(ActivityManagerShellCommand.java:367)
at com.android.server.am.ActivityManagerShellCommand.runSendBroadcast(ActivityManagerShellCommand.java:788)
at com.android.server.am.ActivityManagerShellCommand.onCommand(ActivityManagerShellCommand.java:214)
at com.android.modules.utils.BasicShellCommandHandler.exec(BasicShellCommandHandler.java:97)
at android.os.ShellCommand.exec(ShellCommand.java:38)
at com.android.server.am.ActivityManagerService.onShellCommand(ActivityManagerService.java:10429)
at android.os.Binder.shellCommand(Binder.java:986)
at android.os.Binder.onTransact(Binder.java:860)
at android.app.IActivityManager$Stub.onTransact(IActivityManager.java:6049)
at com.android.server.am.ActivityManagerService.onTransact(ActivityManagerService.java:3034)
at android.os.Binder.execTransactInternal(Binder.java:1220)
at android.os.Binder.execTransact(Binder.java:1179)
fjp#fMac-19 sensorsw % adb shell am broadcast -a android.intent.action.MOVESENSE --es type get --es path Info --es value '''{}'''
Broadcasting: Intent { act=android.intent.action.MOVESENSE flg=0x400000 (has extras) }
Broadcast completed: result=0
The suspects
Is my problems due to an old version of the Android app? I could not find anything newer than 1.5.1.
I tried to poke around a bit in the phone using adb shell dumpsys activity services | grep android.intent.action, and got a load of results, I then started to look for MOVESENSE as well using adb shell dumpsys activity services | grep MOVESENSE, and got no hits. I'm on thin ice here, but could it be that there should be an android.intent.action.MOVESENSE in there someplace?
After a lot of trial and error, I have finally found a solution.
The solution
I found aBitbucket directory with a lot of precompiled Android apps.
The file Showcaseapp-debug_adb-bridge-build.apk is the one you want. Here is what you do:
Download Showcaseapp-debug_adb-bridge-build.apk, and place it in your directory of choice.
On your Android device, uninstall the Showcase app if you have installed it already.
Install the app using ADB on your computer: adb install Showcaseapp-debug_adb-bridge-build.apk.
Start the app on your Android device and connect to the Movesense device.
Try a command like:
Switch LED on: adb shell am broadcast -a android.intent.action.MOVESENSE --es type put --es path Component/Led --es value '''{\"isOn\":true}'''
Switch LED off: adb shell am broadcast -a android.intent.action.MOVESENSE --es type put --es path Component/Led --es value '''{\"isOn\":false}'''
A final note
In a perfect world, Movesense would make wbcmd capable of using theBLE device built into most/all PCs, be it Windows, Linux, or Mac. Or even perfecter (is that a word?), make a variant that used TCP/IP instead of standard in/out.
I'm using buildroot to compile a minimalistic linux with a 4.19-rt kernel. It is supposed to run on a raspberry pi 3b (arm processor). Additionally I want to run it on a x86_64 linux computer and found qemu as an emulation solution for that.
Building linux and kernel and running it on the raspi works. It boots, I can login and use it.
To test qemu I followed this instruction [1]. A recent raspbian with 4.19 kernel is booting fine so qemu seems to be installed correctly.
sudo qemu-system-arm -kernel ./qemu-rpi-kernel/kernel-qemu-4.19.50-buster -hda 2019-09-26-raspbian-buster-lite.img -cpu arm1176 -m 256 -M versatilepb -no-reboot -serial stdio -append "root=/dev/sda2 panic=1 rootfstype=ext4 rw" -dtb qemu-rpi-kernel/versatile-pb.dtb
Bringing 1. and 2. together fails. When I try to emulate any self build linux, qemu only shows a black screen and one CPU is using 100%.
I used the same sdcard.img that works on the real hardware. I also tried to recompile the whole system with a normal 4.19 kernel (without real time). And I tried to build a versatile system (make qemu_arm_versatile_defconfig && make). None of it works.
Command to start the emulation:
sudo qemu-system-arm -kernel zImage -drive format=raw,file=sdcard.img -cpu arm1176 -m 256 -M versatilepb -no-reboot -append "root=/dev/mmcblk0p2 panic=1 rootfstype=ext4 rw" -serial stdio
My main problem is, that there is absolutly no useful output. The command outputs the following
ALSA lib pulse.c:242:(pulse_connect) PulseAudio: Unable to connect: Connection refused
sdl: SDL_OpenAudio failed
sdl: Reason: ALSA: Couldn't open audio device: Connection refused
ALSA lib pulse.c:242:(pulse_connect) PulseAudio: Unable to connect: Connection refused
sdl: SDL_OpenAudio failed
sdl: Reason: ALSA: Couldn't open audio device: Connection refused
audio: Failed to create voice `lm4549.out'
and opens a window for the graphics output (that does not show anything). The message also appears when emulating raspbian so it does not seem to be the reason.
When I run qemu with the prebuild raspbian but without the -dtb argument, I get a message like "Error: invalid dtb and unrecognized/unsupported machine ID". I would at least expect something like this with my self build code. But because there is no output I'm out of ideas what even to google for.
Does someone maybe have an idea what I'm doing wrong or how I get qemu to provide me any useful information on what went wrong?
[1] https://blog.agchapman.com/using-qemu-to-emulate-a-raspberry-pi/
The problem is that a kernel will only boot on a piece of Arm hardware if it is compiled for that hardware. Otherwise it will generally fail, usually by crashing before it is able to output anything useful.
In particular, the QEMU 'versatilepb' machine is completely different to the Raspberry Pi. Any working set of instructions that use that machine type are really running a kernel built to work with the versatilepb board and a raspi userspace/filesystem on top of that. You're trying to build a kernel that has support for only the raspi on a machine that isn't a raspi, which won't work.
It is possible to build a kernel that works on more than one piece of Arm hardware, if you compile in the support for both board types (all the device drivers for both, etc). If you want to go down that path, I would suggest looking at the differences between the kernel config for the kernel that works and your one, and add plausible looking missing things until you find out what is actually required.
Your attempt to boot on QEMU directly from sdcard.img will not work, because QEMU's versatilepb board model does not support direct boot from sdcard (this would require us to run some kind of BIOS/firmware image in the guest, which we don't have). For versatilepb you need to supply directly to QEMU the kernel, possibly an initrd, and definitely the correct dtb for the versatilepb.
You might instead try looking at QEMU's "raspi2" and "raspi3" board models, which really do model the hardware of Raspberry Pis. The disadvantages however are that these models are missing some features and are not very actively developed, so often newer kernels don't boot on them, and also since there is no USB controller model there is no way to get networking. (This is why most blog posts etc suggest using the 'versatilepb' -- userspace doesn't often really care about exactly what hardware it's running on, so unless you're trying to do kernel development you can just run a versatilepb kernel and take advantage of the features like networking that that QEMU model has.)
Advanced Linux Sound Architecture (ALSA) tries to open audio interface device . you must provide audio device in qemu . Because the kernel is compiled with ALSA audio driver and you have compiled sdl library in Buildroot.
We are running the latest raspibian on the raspberry pi board and have a kernel driver for a USB peripheral which is added externally (sudo insmod driverx.ko) after boot-up by connecting to the hardware using ssh (its a headless system).
The problem is as follows:
If the device is already connected to the system upon power-up then running sudo insmod driverx.ko leads to the terminal getting stuck (no response, Ctrl+C doesn't work). Running lsmod by starting another ssh session shows that the module is in use even though there is no code running that will use it.
If I plug the USB device after the system boots up then sudo insmod driverx.ko works normally, (the terminal is still active). Running lsmod subsequently shows that that module is loaded but not in use by anyone. I can then run my user code and everything is fine. Upon running my user code lsmod shows the kernel module is in use and the number of users is 1.
In our system the USB device will always be plugged in. The kernel version and the driver version are the same.
I can fill in more details but do not wish to bias or make this query un-readble.
Please advise on what could the problem be.
Thank you for your time and help.
Possibility is that, the device is already attached into some other driver during startup. If it’s the case, the device credential of your specific device has to be removed from the startup driver.
Check the USB device list before to insert your driver.
After the migration of my development environment from El Capitan to Sierra and updating Tizen Studio from 1.0.1 to 1.1.1 the SDB CLI does not work any more on my new machine. I have installed JDK 1.8.0_121.
I can not really start a SDB server.
$ sdb devices
* server not running. starting it now on port 26099 *
fatal: server listener(26099) cannot bind
Then the following is returned:
* server started successfully *
But I can not connect to devices or list them:
$ sdb devices
runs into endless loop without feedback.
I have tested also the old Tizen Studio version 1.0.1 but got the same result. Can this be a Java or MacOS problem?
Any hints what can be the problem?
Seems to be an issue with SDB and probably Mac OS Sierra.
I have downgraded to Smart Development Bridge version 2.2.67 and sdb works fine. All newer version occur the same problem.
You need to kill the process that sdb cannot bind and then start sdb again with sdb start-server
To find out what process port 26099 is taking
sudo lsof -i:26099
The output
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
sdb 3495 lucasbatista 5u IPv4 0x401834fdf37019a7 0t0 TCP *:26099 (LISTEN)
To kill the process
kill <pid>
In this case
kill 3495
Note:
I realized that the process that occupies this port, is usually the emulator itself when we started with Tizen Studio.
Now, I don't know why sdb simply does not choose another port to start or the emulator does not start on another port, since the developers of Tizen Studio, must have the knowledge that the default sdb port is 26099
Anyway, this step by step that I mentioned above, works for me, I hope it works for you too
I am currently taking an operating systems class and I need to use qemu to run a small operating system that my professor provided. I am trying to use qemu within an ubuntu 12.04 virtual machine on virtualbox on my macbook air 5.2. I know the problems I am having probably have to do with nested virtualization but the specific error I get when I try to run qemu is:
Could not access the KVM kernel module: No such file or directory
failed to initialize KVM: no such file or directory
Back to tcg accelerator.
qemu does start up the os but the window flickers quite a lot and I would like to fix the KVM problem if possible. I've done research but I can't find a solution I can understand or that works so any help would be greatly appreciated.
Also for the ubuntu virtual machine in virtualbox I have both Enable VT-x/AMD-V and Enable Nested Paging checked under Hardware Virtualization. I've also tried using
modprobe kvm-intel
and I get this error:
FATAL: Error inserting kvm_intel (/lib/modules.3.5.0-22-generic/kernel/arch/x86/kvm/kvm-intel.ko): Operation not permitted.
In my case, the virtualization was disabled.
So sudo modprobe kvm-intel kept giving me the following error
could not insert 'kvm_intel': Operation not supported
I just had to go in the BIOS and enable Virtualization.
Try with sudo modprobe kvm-intel.
In order to have the module automatically loaded at the startup of the virtual machine, do the following:
Edit the corresponding file from the shell with sudo vim /etc/modules.conf
Possibly enter your username password.
Press the key G to go to the end of the document and then o to begin inserting.
Write kvm-intel and press Enter, producing a new line.
Press Esc to return to the Normal mode of vim. "--INSERT--" will disappear from
the bottom.
Save the file and exit vim by writing :wq.
You are done. Try to reboot and load the nested virtual machine.