Frequently Asked Questions

Here are some frequently asked questions about the ACRN project.

What Hardware Does ACRN Support?

ACRN runs on Intel-based boards, as documented in our Supported Hardware documentation.

How Do I Configure ACRN’s Memory Size?

It’s important that the ACRN configuration settings are aligned with the physical memory on your platform. Check the documentation for these option settings for details:

• hv.MEMORY.PLATFORM_RAM_SIZE

• hv.MEMORY.HV_RAM_SIZE

Check the Introduction to ACRN Configuration for more information on how to adjust these settings.

Why Does ACRN Need to Know How Much RAM the System Has?

Configuring ACRN at compile time with the system RAM size is a tradeoff between flexibility and functional safety certification. For server virtualization, one binary is typically used for all platforms with flexible configuration options given at run time. But, for IoT applications, the image is typically configured and built for a particular product platform and optimized for that product.

Important features for ACRN include Functional Safety (FuSa) and real-time behavior. FuSa requires a static allocation policy to avoid the potential of dynamic allocation failures. Real-time applications similarly benefit from static memory allocation. This is why ACRN removed all malloc()-type code, and why it needs to pre-identify the size of all buffers and structures used in the Virtual Memory Manager. For this reason, knowing the available RAM size at compile time is necessary to statically allocate memory usage.