Using Hybrid Mode on the NUC¶

ACRN hypervisor supports a hybrid scenario where the User VM (such as Zephyr or Clear Linux) runs in a pre-launched VM or in a post-launched VM that is launched by a Device model in the Service VM. The following guidelines describe how to set up the ACRN hypervisor hybrid scenario on the Intel NUC, as shown in Figure 45.

Figure 45 The Hybrid scenario on the Intel NUC

Prerequisites¶

Use the Intel NUC Kit NUC7i7DNHE.
Connect to the serial port as described in Connecting to the serial port.
Install GRUB on your SATA device or on the NVME disk of your NUC.

Update Ubuntu GRUB¶

Perform the following to update Ubuntu GRUB so it can boot the hypervisor and load the kernel image:

Append the following configuration in the /etc/grub.d/40_custom file:
```
menuentry 'ACRN hypervisor Hybird Scenario' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-e23c76ae-b06d-4a6e-ad42-46b8eedfd7d3' {
   recordfail
   load_video
   gfxmode $linux_gfx_mode
   insmod gzio
   insmod part_gpt
   insmod ext2
   echo 'Loading hypervisor Hybrid scenario ...'
   multiboot --quirk-modules-after-kernel /boot/acrn.32.out
   module /boot/zephyr.bin xxxxxx
   module /boot/bzImage yyyyyy

}
```
Note

The module /boot/zephyr.bin is the VM0 (Zephyr) kernel file. The param xxxxxx is VM0’s kernel file tag and must exactly match the kernel_mod_tag of VM0 which is configured in the hypervisor/scenarios/hybrid/vm_configurations.c file. The multiboot module /boot/bzImage is the Service VM kernel file. The param yyyyyy is the bzImage tag and must exactly match the kernel_mod_tag of VM1 in the hypervisor/scenarios/hybrid/vm_configurations.c file. The kernel command line arguments used to boot the Service VM are located in the header file hypervisor/scenarios/hybrid/vm_configurations.h and are configured by the SOS_VM_BOOTARGS macro.
Modify the /etc/default/grub file as follows to make the GRUB menu visible when booting:
```
# GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=false
```
Update GRUB:
```
$ sudo update-grub
```
Reboot the NUC. Select the ACRN hypervisor Hybrid Scenario entry to boot the ACRN hypervisor on the NUC’s display. The GRUB loader will boot the hypervisor, and the hypervisor will start the VMs automatically.

Hybrid Scenario Startup Checking¶

Use these steps to verify that the hypervisor is properly running:
1. Log in to the ACRN hypervisor shell from the serial console.
2. Use the vm_list command to verify that the pre-launched VM and Service VM are launched successfully.
Use these steps to verify all VMs are running properly:
1. Use the vm_console 0 to switch to VM0 (Zephyr) console. It will display Hello world! acrn.
2. Enter Ctrl+Spacebar to return to the ACRN hypervisor shell.
3. Use the vm_console 1 command to switch to the VM1 (Service VM) console.
4. Verify that the VM1’s Service VM can boot up and you can log in.
5. ssh to VM1 and launch the post-launched VM2 using the ACRN device model launch script.
6. Go to the Service VM console, and enter Ctrl+Spacebar to return to the ACRN hypervisor shell.
7. Use the vm_console 2 command to switch to the VM2 (User VM) console.
8. Verify that VM2 can boot up and you can log in.

Refer to the ACRN Shell Commands for more information about available commands.