Running SBSA Reference Platform – Marcin Juszkiewicz

This post is part 4 of the "SBSA Reference Platform in QEMU" series:

Recently people asked me how to run SBSA Reference Platform for their own testing and development. Which shows that I should write some documentation.

But first let me blog about it…

Requirements

To run SBSA Reference Platform emulation you need:

QEMU (8.2+ recommended)
EDK2 firmware files

That’s all. Sure, some hardware resources would be handy but everyone has some kind of computer available, right?

QEMU

Nothing special is required as long as you have qemu-system-aarch64 binary available.

EDK2

We provide EDK2 binaries on CodeLinaro server. Go to “latest/edk2” directory, fetch both “SBSA_FLASH*” files, unpack them and you are ready to go. You may compare checksums (before unpacking) with values present in “latest/README.txt” file.

Those binaries are built from release versions of Trusted Firmware (TF-A) and Tianocore EDK2 plus latest “edk2-platforms” code (as this repo is not using tags).

Building EDK2

If you decide to build EDK2 on your own then we provide TF-A binaries in “edk2-non-osi” repository. I update those when it is needed.

Instructions to build EDK2 are provided in Qemu/SbsaQemu directory of “edk2-platforms” repository.

Running SBSA Reference Platform emulation

Note that this machine is fully emulated. Even on AArch64 systems where virtualization is available.

Let go through example QEMU command line:

qemu-system-aarch64
-machine sbsa-ref
-drive file=firmware/SBSA_FLASH0.fd,format=raw,if=pflash
-drive file=firmware/SBSA_FLASH1.fd,format=raw,if=pflash
-serial stdio
-device usb-kbd
-device usb-tablet
-cdrom disks/alpine-standard-3.19.1-aarch64.iso

At first we select “sbsa-ref” machine (defaults to four Neoverse-N1 cpu cores and 1GB of ram). Then we point to firmware files (order of them is important).

Serial console is useful for diagnostic output, just remember to not press Ctrl-C there unless you want to take whole emulation down.

USB devices are to have working keyboard and pointing device. USB tablet is more useful that USB mouse (-device usb-mouse adds it). If you want to run *BSD operating systems then I recommend to add USB mouse.

And the last entry adds Alpine 3.19.1 ISO image.

System boots to text console on graphical output. For some reason boot console is on serial port.

Adding hard disk

If you want to add hard disk then adding “-hdb disk.img” is enough (“hdb” as cdrom took 1st slot on the AHCI controller).

Handy thing is “virtual FAT drive” which allows to create guest’s drive from directory on the host:

-drive if=ide,file=fat:ro:DIRECTORY_ON_HOST,format=raw

This is useful for running EFI binaries as this drive is visible in UEFI environment. It is not present when operating system is booted.

Adding NVME drive

NVME is composed from two things:

PCIe device
storage drive

So let add it in a nice way, using PCIe root-port:

-device pcie-root-port,id=root_port_for_nvme1,chassis=2,slot=0
  -device nvme,serial=deadbeef,bus=root_port_for_nvme1,drive=nvme
     -drive file=disks/nvme.img,format=raw,id=nvme,if=none

Using NUMA configuration

QEMU can emulate Non-Uniform Memory Access (NUMA) setup. This usually means multisocket systems with memory available per cpu socket.

Example config:

-smp 4,sockets=4,maxcpus=4
-m 4G,slots=2,maxmem=5G
-object memory-backend-ram,size=1G,id=m0
-object memory-backend-ram,size=3G,id=m1
-numa node,nodeid=0,cpus=0-1,memdev=m0
-numa node,nodeid=1,cpus=2,memdev=m1
-numa node,nodeid=2,cpus=3

This adds four cpu sockets and 4GB of memory. First node has 2 cpu cores and 1GB ram, second node has 1 cpu and 3GB of ram and last node has 1 cpu without local memory.

Note that support for such setup in work in progress now (March 2024). We merged required code into TF-A and have set of patches for EDK2 in review. Without them you will see resources only from the first NUMA node.

Complex PCI Express setup

Our platform has GIC ITS support so we can try some complex PCI Express structures.

This example uses PCIe switch to add more PCIe slots and then (to complicate things) puts PCIe-to-PCI bridge into one of them to make use of old Intel e1000 network card:

-device pcie-root-port,id=root_port_for_switch1,chassis=0,slot=0
  -device x3130-upstream,id=up_port1,bus=root_port_for_switch1
    -device xio3130-downstream,id=down_port1,bus=up_port1,chassis=1,slot=0
      -device ac97,bus=down_port1
    -device xio3130-downstream,id=down_port2,bus=up_port1,chassis=1,slot=1
   -device pcie-pci-bridge,id=pci1,bus=down_port2
     -device e1000,bus=pci1,addr=2

Some helper scripts

During last year I wrote some helper scripts for working with SBSA Reference Platform testing. They are stored in sbsa-ref-status repository on GitHub.

May lack up-to-date documentation but can show my way of using the platform.

Summary

SBSA Reference Platform can be used for testing several things. From operating systems to (S)BSA compliance of the platform. Or to check how some things are emulated in QEMU. Or playing with PCIe setups (NUMA systems can have separate PCI Express buses but we do not handle it yet in firmware).

Have fun!