I am trying to read the LDD book by Jonathan Corbet, Greg Kroah-Hartman, Alessandro Rubini and implement the sample modules. So to begin with, I tried setting up a development system. Installed Ubuntu 16.04 Xenial. Now, I just created a directory and wrote the hello_world module with a Makefile. Got it built and run it, verified the dmesg logs.
Is that all the development setup? I searched online and found articles where they are asking to download and compile the kernel, use a VM to boot the kernel. What is the reason? Or what am I missing?
Is there any better article which clarifies this?
Thanks
hago
You can try one more way:
If you have native windows, install virtual machine software such as
Virtual box. Get your favourite Linux distribution (no bias, just
an example - Ubuntu) and install it through Virtual box.
Get the latest kernel (or of your choice) from kernel.org.
Choose the platform you want to build this kernel for. E.g arm64 or x86.
In case you do not have real boards (e.g RPi for arm variant), you can use qemu-arm64 or qemu-x86 to run your compiled kernel. This is also a good option when users do not have the boards.
Another good use case for using qemu for the newbie kernel developers is even they write some modules which crashes, then the qemu instance is crashed so no harm.
I think using qemu is a good option for people who starts to learn kernel programming and also want to try writing some of their modules and do not intend to purchase hardware at this point of time.
It depends on your target. For your case, you have made a kernel driver for your computer (it run Linux kernel).
But if you want to develop a Kernel driver for another target like Rasberry Pi, ARM board, X86-X64 board, ... you must learn to compile, edit Kernel config, boot Kernel image, ... because each target has different kernel versions.
You can refer to this training for more detail: https://bootlin.com/training/embedded-linux/
I have multiple questions regarding debugging a Raspberry pi 3 from a linux x64 host using gdb-multiarch, as well as writing bare metal programs in general. We are currently facing a problem where our code appears to not be loaded into memory. When we begin debugging in GDB we start at address 0. 3 instructions down we jump into 0x10000. If I modify my linker script to put the Raspberry pi into either address I get the same result, we jump into 0x10000 and our code isn't loaded there. Instead we get this
We noticed also that GDB is using 32 bit register names here when we're supposed to be debugging 64 bit code.
Again a recap of what we're using:
QEMU with versatile-pb machine.
An aarch64 GCC cross-compiler.
GDB-multiarch.
We've tried on two different hosts: Ubuntu 16.04 x64 Host running in virtualbox. Mint x64 running natively.
We also tried the arm-none-eabi toolchain but were running into problems not having our code compiled as 64 bit.
Help is much appreciated! Thanks!
You don't give your command line, but "versatile-pb" is a 32-bit only board type, so trying to run 64-bit code on it is going to misbehave in confusing ways. You need to tell QEMU to emulate a 64-bit capable board that matches what your bare-metal code is expecting to run on.
In QEMU 2.12 there will be a "raspi3" QEMU board which may be helpful for you; you'd need to try building the latest 2.12 release candidate tarball at the moment if you wanted to experiment with that (2.12 release isn't due for another couple of weeks). Otherwise you could use the "virt" board if you made sure your bare metal code was built to be able to run on that board.
I was so happy today that I have been finally able to install Windows Phone 8 SDK and try it a bit. I installed fresh new installation of Windows 8 Pro into my virtual machine (I am running if from Parallels) and then installed Windows Phone 8 SDK.
Everything went smooth, Visual Studio Express is installed and running, but when I created new project and tried to deploy it, VS fails with really weird message.
First of all, message box informing that "The Windows Phone Emulator wasn't able to create the virtual machine: Generic failure" appears. Really informing, really professional - generic error, that's really good. Then the information that deployment failed appears (thanks a lot for keeping me informed about that, I didn't noticed that it crashed completely). And then in the Error List, there is an information about "Invalid pointer" - even better. No clue at all about what failed or what's wrong.
Can anybody help me with that? There is nothing on the internet about this topic so far and I don't know where the problem is. I scanned the Windows events and logs, but there is nothing (probably I haven't been searching properly, so please guide me through that if you can).
Anybody can help?
The Windows Phone 8 emulator requires hardware Hyper-V support. In particular, it requires second-level address translation, hardware assisted virtualization, and hardware DEP support enabled and to not be ran in a hypervisor(no nesting). If you bought your machine within the past 4 years you should have no problem with these requirements. You can check out this article to see more information about that and how to find if your PC supports it.
Because of these hardware requirements, this means you can't run the phone emulator inside of most virtualization technologies... With one exception: I've been using VMWare 9 which appears to include an "unsupported" feature to allow Hyper-V to work though.. So your only choice for running the phone emulator is to either buy VMWare 9 (or 8 with more configuration) or upgrade a physical machine to Windows 8
The unsupported way VMWare allows you to run Hyper-V inside of a VM is that there is a manual option (hypervisor.cpuid.v0 = “FALSE”) which basically tells VMWare not to report to the virtual machine that it's running in a VM. Hyper-V checks if it's running in a VM and won't work if it is, so this gets Hyper-V to work past that check. I personally have tested this whole nested-VM thing with the Phone emulator(including before public release), and other than being quite slow, it does work pretty well with no immediate crashes or anything.
There is a workaround for VMWare Workstation 8 as well in an answer below. However, 9 is much easier to configure, so if you have it use this method.
I ran into the same issue and I fixed it by enabling Hypervisor applications in this virtual machine and adding the following line to the .vmx file:
hypervisor.cpuid.v0 = "FALSE"
This got the emulator working just fine. I found this answer here.
Hope this helps.
Actually, it works quite nicely with VMware Fusion 5.0.1
All I had to do is to add to the .vmx file of the virtual machine the following lines:
hypervisor.cpuid.v0 = “FALSE”
vhv.enable = "true"
Save and restart VMWARE (obviously the VM must be stopped before the changes are made)
I'm right now debugging a test app from VS2012 using the emaulator inside a VM in my Macbook
I'm a happy camper
:-)
I posted the same question on Parallels forum.
Reply:
The emulator is actually a virtual machine, so we are talking about a vm inside a vm, this requires support for nested Hyper-V, which afaik is planned but not implemented yet, also VMWare Fusion already supports this, if you are so desperate.
————-
See Parallels forum post: http://forum.parallels.com/showthread.php?p=646448#post646448
This works for me
Set RAM to 4g
Set at least 2 cores
add to vmx file.
vhv.enable = "TRUE"
hypervisor.cpuid.v0="FALSE"
Goot article
http://social.msdn.microsoft.com/Forums/en-US/wptools/thread/ed72010c-321c-4667-97b2-3ff1540e7f87/
You need SLAT compatible hardware to run Hyper-V, which is a requirement for using the emulator.
Can you clarify what kind of hardware you're attempting to run this on, and if you have enabled Virtualization in your BIOS settings?
The "Invalid pointer" error just means it cannot connect to the emulator (and/or device).
Just as an addition to https://stackoverflow.com/a/13163762/1964969 (top answer at the moment):
manually appending "hypervisor.cpuid.v0" key works for VmWare Player 5 as well (the main reason - this software is free for non-commercial use so it's perfect product if you test the waters, just download from VmWare website and install, it's fully-functional).
Slightly unexpected, any of the following amends solve the problem with WP8 emulator:
hypervisor.cpuid.v0="FALSE"
hypervisor.cpuid.v0="TRUE"
hypervisor.cpuid.v0=""
Yeah, you can apply empty value for that key - but why? Have no idea but it works. I did some notes in my blog as well:
http://windowsasusual.blogspot.ru/2013/01/how-to-launch-windows-phone-8-emulator.html
Under Parallels Desktop 8 follow this guide: http://kb.parallels.com/en/115211
Edit:
Oh, I didn't noticed that you are trying to run emulator on VM. My answer is for non-VM environment.
First of all, you need to check hardware requirement at here
Be careful, successful installation of SDK does not guarantee "your hardware is compatible"
If your hardware is compatible and Hyper-V is running(described in the link above), please check your BIOS and be sure to enable hardware virtualization in CPU Configuration
(for me, I could find it at Booting > BIOS > Advanced > Advanced > CPU Configuration)
Brief summary:
64bit CPU and OS
4GB RAM
Hardware-assisted virtualization supported CPU
Second Level Address Translation (SLAT) supported hardware
Hardware-based Data Execution Prevention (DEP) supported hardware
Proper BIOS settings
For me the solution adding line:
hypervisor.cpuid.v0 = "FALSE"
I use VMware Player and added the line (hypervisor.cpuid.v0 = "FALSE")in the .vmx file.
My virtual machine with Windows 8 Pro runs the emulator for Windows Phone 8 perfectly.
Solved the problem by uninstalling an older VPN client from the machine. It turns out some VPN clients might have compatibility issues with Windows 8. After uninstalling VPN client I was able to run the emulator without issues (of course after making sure Hyper-V was installed and enabled on the machine)
Not enough rep. to comment on the accepted answer, but Microsoft provide instructions specifically for Fusion here. It worked for me, after a couple of reboots of both Mac and VM. I installed W8.1 without Hyper-V support initially and had to install it after the fact ("Turn Windows Features On or Off" in Control Panel), but apart from that no problems. Quite speedy on a 16Gb 2013 MBP.
My ultimate goal is to do some programming for the Angstrom Linux (or Debian or other Linux distros), on QEMU emulating ARM processor board s.a. Versatile board. I am happy to experiement, but if someone has attempted something similar, and can give little guidance, it might hasten progress.
My understanding of the steps needed are:-
1. Build QEMU from source (although I am not sure if a prebuilt binary won't do). I found QEMuManager on Windows (XP being my Desktop OS on which I intend to run QEMU).
2. Install ARM tool chain (e.g. Yagarto / GNU-ARM for Cygwin?)
3. Download an Angstrom Linux tarball and build it
4. Create a QEMU image with Angstrom Linux.
However I am missing on the details, as I believe there are choices to be made at each of those steps.
IMHO you should use a linux distribution as host machine for your QEmu instead of trying to compile/install all the QEmu stuff in a cygwin based system, it will remove some futur headaches. You can use a VMWare player with an ubuntu image.
I used to play with this tutorial for Debian on QEMU.
The beagleboard, hawkboard, open-rd sites all tend to lead to their distros being built on qemu (arm), and from there there is no reason why you cannot just continue to keep running on the simulation instead of heading for hardware.
This is an example of how to do it with ubuntu.
https://wiki.edubuntu.org/ARM/RootfsFromScratch
Yes it is also possible to cross compile everything as well, I would start with wiki pages that hand hold you through all of the steps. Or as with the hawkboard or beagleboard get a pre-built binary (kernel and root file system) and just boot it and run on that environment and not mess with building everything.
I've got a driver for a custom PCI card, which builds and runs fine on XP. I'm trying to use this custom hardware on W7, and am trying to build and run my driver.
I've got the latest DDK from Microsoft, and build my driver for XP using Windows XP "x86 Free Build Environment". Everything installs & works fine. (Build using a DDK "build" command)
If I use the Windows 7 "x86 Free Build Environment" build environment, everything builds fine. I run it through the PREfast and staticdv code checkers, no errors from either. ( I get a couple of warnings about "The dispatch function 'FooFnc' does not have any __drv_dispatchType annotations" - are these likely to be the issue? )
When I install, the install starts OK (standard error about drivers not being signed), but gets to a certain point and then hangs, then fails with a timeout error. The device then shows up in device manager as installed. At this point the PC won't shutdown or boot, but hangs indefinitely. I'm forced to boot into Safe Mode and uninstall the driver from there.
So my question(s) are:
If there has been a change in the driver model between XP and W7, what's the best way to find it? I can't see anything on MSDN.
How would I go about debugging the driver? The box doesn't start, so it's not like I can run up WinDBG.
Any specific W7 driver gotchas that are hidden away?
I've tried to keep this as generic as possible, but if more detail would be helpful I'll provide more
AFAIK, the biggest changes have been made in video and network drivers. Other drivers retain backward compatibility and can be run on W7 even with no recompiling.
Run your driver under driver verifier and turn on generating crash dumps with a keyboard (very helpful in case of system hangs, you can manually generate crashdump, analyze it and find what was wrong).
Hope this helps!