# Building for Emulation

Building an image for emulation allows you to simulate your
image without actual target hardware.

This section describes the steps you need to take to build the
AGL demo image for emulation using either Quick EMUlator (QEMU) or
VirtualBox.

## 1. Making Sure Your Build Environment is Correct

The
"[Initializing Your Build Environment](../image-workflow-initialize-build-environment.html/Initializing-your-build-environment)"
section presented generic information for setting up your build environment
using the `aglsetup.sh` script.
If you are building the AGL demo image for emulation, you need to specify some
specific options when you run the script:

```bash
source meta-agl/scripts/aglsetup.sh -f -m qemux86-64 agl-demo agl-devel
```

The "-m" option specifies the "qemux86-64" machine.
The list of AGL features used with script are appropriate for development of
the AGL demo image suited for either QEMU or VirtualBox.

## 2. Using BitBake

This section shows the `bitbake` command used to build the AGL image.
Before running BitBake to start your build, it is good to be reminded that AGL
does provide pre-built images for developers that can be emulated
using QEMU and VirtualBox.
You can find these pre-built images on the
[AGL Download web site](https://download.automotivelinux.org/AGL/release).

For supported images, the filenames have the following forms:

```
<release-name>/<release-number>/qemuarm/*
<release-name>/<release-number>/qemuarm64/*
<release-name>/<release-number>/qemux86-64/*
```

Start the build using the `bitbake` command.

**NOTE:** An initial build can take many hours depending on your
CPU and and Internet connection speeds.
The build also takes approximately 100G-bytes of free disk space.

For this example, the target is "agl-demo-platform":

```bash
  bitbake agl-demo-platform
```

By default, the build process puts the resulting image in the Build Directory:

```
<build_directory>/tmp/deploy/images/qemux86-64/agl-demo-platform-qemux86-64.vmdk.xz
```

## 3. Deploying the AGL Demo Image

Deploying the image consists of decompressing the image and then
booting it using either QEMU or VirtualBox.

### Decompress the image:

For Linux, use the following commands to decompress the image and prepare it for boot:

```bash
cd tmp/deploy/images/qemux86-64
xz -d agl-demo-platform-qemux86-64.vmdk.xz
```

For Windows, download [7-Zip](http://www.7-zip.org/) and then
select **agl-demo-platform-qemux86-64.vmdk.xz** to decompress
the image and prepare it for boot.

### Boot the Image:

The following steps show you how to boot the image with QEMU or VirtualBox.

#### QEMU

Depending on your Linux distribution, use these commands to install QEMU:

**NOTE:** if you have created an AGL crosssdk, it will contain a
QEMU binary for the build host.
This SDK QEMU binary does not support graphics.
Consequently,  you cannot use it to boot the AGL image.

If your build host is running
[Arch Linux](https://www.archlinux.org/), use the following commands:

```bash
sudo pacman -S qemu
```

If your build host is running Debian or Ubuntu, use the following commands:

```bash
sudo apt-get install qemu-system-x86
```

If you build host is running Fedora, use the following commands:

```bash
sudo yum install qemu-kvm
```

Once QEMU is installed, boot the image with KVM support:

```bash
qemu-system-x86_64 -enable-kvm -m 2048 \
    -hda agl-demo-platform-qemux86-64.vmdk \
    -cpu kvm64 -cpu qemu64,+ssse3,+sse4.1,+sse4.2,+popcnt \
    -vga virtio -show-cursor \
    -device virtio-rng-pci \
    -serial mon:stdio -serial null \
    -soundhw hda \
    -net nic,vlan=0 \
    -net user,hostfwd=tcp::2222-:22
```

#### VirtualBox

Start by downloading and installing [VirtualBox](https://www.virtualbox.org/wiki/Downloads) 5.2.0 or later.

Once VirtualBox is installed, follow these steps to boot the image:

1. Start VirtualBox
2. Click **New** to create a new machine
3. Enter **AGL QEMU** as the *Name*
4. Select **Linux** as the *Type*
5. Select **Other Linux (64-bit)** as the *Version*
6. Set *Memory size* to **2 GB**
7. Click **Use an existing virtual hard disk file** under *Hard disk*
8. Navigate to and select the **agl-demo-platform-qemux86-64.vmdk** image
9. Ensure that the newly created **AGL QEMU** machine is highlighted.
10. Click **Start**