Building Your Own Hardware Designs
This section will guide you through building a Xilinx Alveo U250 FPGA bitstream to run FireSim simulations.
Here, we’ll do some final one-time setup for your Build Farm Machines so that we can build bitstreams for FireSim simulations automatically.
These steps assume that you have already followed the earlier setup steps required to run simulations.
As noted earlier, it is highly recommended that you use Ubuntu 20.04 LTS as the host operating system for all machine types in an on-premises setup, as this is the OS recommended by Xilinx.
Also recall that we make a distinction between the Manager Machine, the Build Farm Machine(s), and the Run Farm Machine(s). In a simple setup, these can all be a single machine, in which case you should run the Build Farm Machine setup steps below on your single machine.
1. Install Vivado for Builds
Machines: Build Farm Machines.
Running builds for Xilinx Alveo U250 in FireSim requires Vivado 2021.1. Other versions are unlikely to work out-of-the-box.
On each Build Farm machine, do the following:
Install Vivado 2021.1 from the Xilinx Downloads Website. By default, Vivado will be installed to
/tools/Xilinx/Vivado/2021.1. We recommend keeping this default. If you change it to something else, you will need to adjust the path in the rest of the setup steps.
Add the following to
vivadois available when
ssh-ing into the machine:
au250board support package directory from https://github.com/Xilinx/open-nic-shell/tree/main/board_files/Xilinx and place the directory in
If you have multiple Build Farm Machines, you should repeat this process for each.
2. Verify Build Farm Machine environment
Machines: Manager Machine and Run Farm Machines
Finally, let’s ensure that Vivado 2021.1 is properly sourced in
your shell setup (i.e.
.bashrc) so that any shell on your Build Farm Machines
can use the corresponding programs. The environment variables should be
visible to any non-interactive shells that are spawned.
You can check this by running the following on the Manager Machine,
localhost if your Build Farm machine
and Manager machine are the same machine, or replacing it with the Build Farm
machine’s IP address if they are different machines.
ssh BUILD_FARM_IP printenv
Ensure that the output of the command shows that the Vivado 2021.1 tools are
present in the printed environment variables (i.e.,
If you have multiple Build Farm machines, you should repeat this process for
each Build Farm machine, replacing
BUILD_FARM_IP with a different Build Farm Machine’s
Configuring a Build in the Manager
deploy/config_build.yaml file, you will notice that the
section currently contains several lines, which
indicates to the build system that you want to run all of these “build recipes” in
parallel, with the parameters for each “build recipe” listed in the relevant section of the
In this guide, we’ll build the default FireSim design for the Xilinx Alveo U250, which is specified
alveo_u250_firesim_rocket_singlecore_no_nic section in
This was the same configuration used to build the pre-built bitstream that you used to run
simulations in the guide to running a simulation.
Looking at the
alveo_u250_firesim_rocket_singlecore_no_nic section in
there are a few notable items:
TARGET_CONFIGspecifies that this configuration is a simple singlecore RISC-V Rocket with a single DRAM channel.
bit-builder-recipes/xilinx_alveo_u250.yaml, which is found in the deploy directory and tells the FireSim build system how to build bitstreams for this FPGA.
Having looked at this entry, let’s now set up the build in
deploy/config_build.yaml. First, we’ll set up the
build_farm mapping, which specifies the Build Farm Machines that are available to build FPGA bitstreams.
base_recipewill map to
build-farm-recipes/externally_provisioned.yaml. This indicates to the FireSim manager that the machines used to run builds are existing machines that have been set up by the user, instead of cloud instances that are automatically provisioned.
default_build_diris the directory in which builds will run out of on your Build Farm Machines. Change the default
nullto a path where you would like temporary build data to be stored on your Build Farm Machines.
build_farm_hostsis a section that contains a list of IP addresses or hostnames of machines in your Build Farm. By default,
localhostis specified. If you are using a separate Build Farm Machine, you should replace this with the IP address or hostname of the Build Farm Machine on which you would like to run the build.
Having configured our Build Farm, let’s specify the design we’d like to build. To do this, edit the
builds_to_run section in
deploy/config_build.yaml so that it looks like the following:
builds_to_run: - alveo_u250_firesim_rocket_singlecore_no_nic
In essence, you should delete or comment out all the other items in the
builds_to_run section besides
Running the Build
Now, we can run a build like so:
This will run through the entire build process, taking the Chisel (or Verilog) RTL
and producing a bitstream that runs on the Xilinx Alveo U250 FPGA. This whole process will
usually take a few hours. When the build
completes, you will see a directory in
deploy/results-build/, named after your build parameter
settings, that contains all of the outputs of the Xilinx Vivado build process.
Additionally, the manager will print out a path to a log file
that describes everything that happened, in-detail, during this run (this is a
good file to send us if you encounter problems).
The manager will also print an entry that can be added to
config_hwdb.yaml so that the
bitstream can be used to run simulations. This entry will contain a
bitstream_tar key whose
value is the path to the final generated bitstream file. You can share generated bitstreams
with others by sharing the file listed in
bitstream_tar and the
entry for it.
Now that you know how to generate your own FPGA image, you can modify the target-design to add your own features, then build a FireSim-compatible FPGA image automatically!
This is the end of the Getting Started Guide. To learn more advanced FireSim features, you can choose a link under the “Advanced Docs” section to the left.