Running a Single Node Simulation

Now that we’ve completed the setup of our manager instance, it’s time to run a simulation! In this section, we will simulate 1 target node, for which we will need a single f1.2xlarge (1 FPGA) instance.

Make sure you are ssh or mosh’d into your manager instance and have sourced sourceme-manager.sh before running any of these commands.

Building target software

In these instructions, we’ll assume that you want to boot Linux on your simulated node. To do so, we’ll need to build our FireSim-compatible RISC-V Linux distro. For this guide, we will use a simple buildroot-based distribution. You can do this like so:

cd ${CY_DIR}/software/firemarshal
./marshal -v build br-base.json
./marshal -v install br-base.json

This process will take about 10 to 15 minutes on a c5.4xlarge instance. Once this is completed, you’ll have the following files:

  • ${CY_DIR}/software/firemarshal/images/firechip/br-base/br-base-bin - a bootloader + Linux kernel image for the nodes we will simulate.

  • ${CY_DIR}/software/firemarshal/images/firechip/br-base/br-base.img - a disk image for each the nodes we will simulate

These files will be used to form base images to either build more complicated workloads (see the [DEPRECATED] Defining Custom Workloads section) or to copy around for deploying.

Setting up the manager configuration

All runtime configuration options for the manager are set in a file called ${FS_DIR}/deploy/config_runtime.yaml. In this guide, we will explain only the parts of this file necessary for our purposes. You can find full descriptions of all of the parameters in the Manager Configuration Files section.

If you open up this file, you will see the following default config (assuming you have not modified it):

# RUNTIME configuration for the FireSim Simulation Manager
# See https://docs.fires.im/en/stable/Advanced-Usage/Manager/Manager-Configuration-Files.html for documentation of all of these params.

run_farm:
  base_recipe: run-farm-recipes/aws_ec2.yaml
  recipe_arg_overrides:
    # tag to apply to run farm hosts
    run_farm_tag: mainrunfarm
    # enable expanding run farm by run_farm_hosts given
    always_expand_run_farm: true
    # minutes to retry attempting to request instances
    launch_instances_timeout_minutes: 60
    # run farm host market to use (ondemand, spot)
    run_instance_market: ondemand
    # if using spot instances, determine the interrupt behavior (terminate, stop, hibernate)
    spot_interruption_behavior: terminate
    # if using spot instances, determine the max price
    spot_max_price: ondemand
    # default location of the simulation directory on the run farm host
    default_simulation_dir: /home/centos

    # run farm hosts to spawn: a mapping from a spec below (which is an EC2
    # instance type) to the number of instances of the given type that you
    # want in your runfarm.
    run_farm_hosts_to_use:
      - f1.16xlarge: 0
      - f1.4xlarge: 0
      - f1.2xlarge: 1
      - m4.16xlarge: 0
      - z1d.3xlarge: 0
      - z1d.6xlarge: 0
      - z1d.12xlarge: 0

metasimulation:
  metasimulation_enabled: false
  # vcs or verilator. use vcs-debug or verilator-debug for waveform generation
  metasimulation_host_simulator: verilator
  # plusargs passed to the simulator for all metasimulations
  metasimulation_only_plusargs: "+fesvr-step-size=128 +max-cycles=100000000"
  # plusargs passed to the simulator ONLY FOR vcs metasimulations
  metasimulation_only_vcs_plusargs: "+vcs+initreg+0 +vcs+initmem+0"

target_config:
    topology: no_net_config
    no_net_num_nodes: 1
    link_latency: 6405
    switching_latency: 10
    net_bandwidth: 200
    profile_interval: -1

    # This references a section from config_hwdb.yaml for fpga-accelerated simulation
    # or from config_build_recipes.yaml for metasimulation
    # In homogeneous configurations, use this to set the hardware config deployed
    # for all simulators
    default_hw_config: midasexamples_gcd

    # Advanced: Specify any extra plusargs you would like to provide when
    # booting the simulator (in both FPGA-sim and metasim modes). This is
    # a string, with the contents formatted as if you were passing the plusargs
    # at command line, e.g. "+a=1 +b=2"
    plusarg_passthrough: ""

tracing:
    enable: no

    # Trace output formats. Only enabled if "enable" is set to "yes" above
    # 0 = human readable; 1 = binary (compressed raw data); 2 = flamegraph (stack
    # unwinding -> Flame Graph)
    output_format: 0

    # Trigger selector.
    # 0 = no trigger; 1 = cycle count trigger; 2 = program counter trigger; 3 =
    # instruction trigger
    selector: 1
    start: 0
    end: -1

autocounter:
    read_rate: 0

workload:
    workload_name: null.json
    terminate_on_completion: no
    suffix_tag: null

host_debug:
    # When enabled (=yes), Zeros-out FPGA-attached DRAM before simulations
    # begin (takes 2-5 minutes).
    # In general, this is not required to produce deterministic simulations on
    # target machines running linux. Enable if you observe simulation non-determinism.
    zero_out_dram: no
    # If disable_synth_asserts: no, simulation will print assertion message and
    # terminate simulation if synthesized assertion fires.
    # If disable_synth_asserts: yes, simulation ignores assertion firing and
    # continues simulation.
    disable_synth_asserts: no

# DOCREF START: Synthesized Prints
synth_print:
    # Start and end cycles for outputting synthesized prints.
    # They are given in terms of the base clock and will be converted
    # for each clock domain.
    start: 0
    end: -1
    # When enabled (=yes), prefix print output with the target cycle at which the print was triggered
    cycle_prefix: yes
# DOCREF END: Synthesized Prints

We won’t have to modify any of the defaults for this single-node simulation guide, but let’s walk through several of the key parts of the file.

First, let’s see how the correct numbers and types of instances are specified to the manager:

  • You’ll notice first that in the run_farm mapping, the manager is configured to launch a Run Farm named mainrunfarm (given by the run_farm_tag). The tag specified here allows the manager to differentiate amongst many parallel run farms (each running some workload on some target design) that you may be operating. In this case, the default is fine since we’re only running a single run farm.

  • Notice that under run_farm_hosts_to_use, the only non-zero value is for f1.2xlarge, which should be set to 1. This is exactly what we’ll need for this guide.

  • You’ll see other parameters in the run_farm mapping, like run_instance_market, spot_interruption_behavior, and spot_max_price. If you’re an experienced AWS user, you can see what these do by looking at the Manager Configuration Files section. Otherwise, don’t change them.

Next, let’s look at how the target design is specified to the manager. This is located in the target_config section of firesim/deploy/config_runtime.yaml, shown below:

target_config:
    topology: no_net_config
    no_net_num_nodes: 1
    link_latency: 6405
    switching_latency: 10
    net_bandwidth: 200
    profile_interval: -1

    # This references a section from config_hwdb.yaml for fpga-accelerated simulation
    # or from config_build_recipes.yaml for metasimulation
    # In homogeneous configurations, use this to set the hardware config deployed
    # for all simulators
    default_hw_config: midasexamples_gcd

    # Advanced: Specify any extra plusargs you would like to provide when
    # booting the simulator (in both FPGA-sim and metasim modes). This is
    # a string, with the contents formatted as if you were passing the plusargs
    # at command line, e.g. "+a=1 +b=2"
    plusarg_passthrough: ""

Here are some highlights of this section:

  • topology is set to no_net_config, indicating that we do not want a network.

  • no_net_num_nodes is set to 1, indicating that we only want to simulate one node.

  • default_hw_config is midasexamples_gcd. This references a bitstream/build-recipe used to run a simulation specified in ${FS_DIR}/deploy/config_hwdb.yaml.

Let’s modify the default_hw_config to instead point to a Chipyard SoC publically available AWS FPGA image. Change the following:

default_hw_config: firesim_rocket_quadcore_no_nic_l2_llc4mb_ddr3

This references a pre-built, publically-available AWS FPGA Image that is specified in ${CY_DIR}/sims/firesim-staging/sample_config_hwdb.yaml. This pre-built image models a Quad-core Rocket Chip with 4 MB of L2 cache and 16 GB of DDR3, and no network interface card. Future steps will require us to point to this Chipyard HWDB YAML file so that the FireSim manager can obtain the hardware configuration.

Attention

[Advanced users] Simulating BOOM instead of Rocket Chip: If you would like to simulate a single-core BOOM as a target, set default_hw_config to firesim_boom_singlecore_no_nic_l2_llc4mb_ddr3.

Finally, let’s take a look at the workload section, which defines the target software that we’d like to run on the simulated target design. By default, it should look like this:

workload:
    workload_name: null.json
    terminate_on_completion: no
    suffix_tag: null

Let’s modify the null.json workload name to point to a workload definition that will boot Linux. Change the following:

workload_name: br-base-uniform.json

This tells the FireSim manager to run the specified buildroot-based Linux (br-base-uniform.json) on our simulated system. The terminate_on_completion feature is an advanced feature that you can learn more about in the Manager Configuration Files section.

Launching a Simulation!

Now that we’ve told the manager everything it needs to know in order to run our single-node simulation, let’s actually launch an instance and run it!

Starting the Run Farm

First, we will tell the manager to launch our Run Farm, as we specified above. When you do this, you will start getting charged for the running EC2 instances (in addition to your manager). As mentioned earlier we need to point to Chipyard’s HWDB file that holds the reference to firesim_rocket_quadcore_no_nic_l2_llc4mb_ddr3.

To do launch your run farm, run:

firesim launchrunfarm -a ${CY_DIR}/sims/firesim-staging/sample_config_hwdb.yaml -r ${CY_DIR}/sims/firesim-staging/sample_config_build_recipes.yaml

You should expect output like the following:

FireSim Manager. Docs: http://docs.fires.im
Running: launchrunfarm

Waiting for instance boots: f1.16xlarges
Waiting for instance boots: f1.4xlarges
Waiting for instance boots: m4.16xlarges
Waiting for instance boots: f1.2xlarges
i-0d6c29ac507139163 booted!
The full log of this run is:
/home/centos/firesim-new/deploy/logs/2018-05-19--00-19-43-launchrunfarm-B4Q2ROAK0JN9EDE4.log

The output will rapidly progress to Waiting for instance boots: f1.2xlarges and then take a minute or two while your f1.2xlarge instance launches. Once the launches complete, you should see the instance id printed and the instance will also be visible in your AWS EC2 Management console. The manager will tag the instances launched with this operation with the value you specified above as the run_farm_tag parameter from the config_runtime.yaml file, which we left set as mainrunfarm. This value allows the manager to tell multiple Run Farms apart – i.e., you can have multiple independent Run Farms running different workloads/hardware configurations in parallel. This is detailed in the Manager Configuration Files and the firesim launchrunfarm sections – you do not need to be familiar with it here.

Setting up the simulation infrastructure

The manager will also take care of building and deploying all software components necessary to run your simulation. The manager will also handle programming FPGAs. To tell the manager to set up our simulation infrastructure, let’s run:

firesim infrasetup -a ${CY_DIR}/sims/firesim-staging/sample_config_hwdb.yaml -r ${CY_DIR}/sims/firesim-staging/sample_config_build_recipes.yaml

For a complete run, you should expect output like the following:

FireSim Manager. Docs: http://docs.fires.im
Running: infrasetup

Building FPGA software driver for FireSim-FireSimQuadRocketConfig-BaseF1Config
[172.30.2.174] Executing task 'instance_liveness'
[172.30.2.174] Checking if host instance is up...
[172.30.2.174] Executing task 'infrasetup_node_wrapper'
[172.30.2.174] Copying FPGA simulation infrastructure for slot: 0.
[172.30.2.174] Installing AWS FPGA SDK on remote nodes.
[172.30.2.174] Unloading XDMA/EDMA/XOCL Driver Kernel Module.
[172.30.2.174] Copying AWS FPGA XDMA driver to remote node.
[172.30.2.174] Loading XDMA Driver Kernel Module.
[172.30.2.174] Clearing FPGA Slot 0.
[172.30.2.174] Flashing FPGA Slot: 0 with agfi: agfi-0eaa90f6bb893c0f7.
[172.30.2.174] Unloading XDMA/EDMA/XOCL Driver Kernel Module.
[172.30.2.174] Loading XDMA Driver Kernel Module.
The full log of this run is:
/home/centos/firesim-new/deploy/logs/2018-05-19--00-32-02-infrasetup-9DJJCX29PF4GAIVL.log

Many of these tasks will take several minutes, especially on a clean copy of the repo. The console output here contains the “user-friendly” version of the output. If you want to see detailed progress as it happens, tail -f the latest logfile in firesim/deploy/logs/.

At this point, the f1.2xlarge instance in our Run Farm has all the infrastructure necessary to run a simulation.

So, let’s launch our simulation!

Running the simulation

Finally, let’s run our simulation! To do so, run:

firesim runworkload -a ${CY_DIR}/sims/firesim-staging/sample_config_hwdb.yaml -r ${CY_DIR}/sims/firesim-staging/sample_config_build_recipes.yaml

This command boots up a simulation and prints out the live status of the simulated nodes every 10s. When you do this, you will initially see output like:

FireSim Manager. Docs: http://docs.fires.im
Running: runworkload

Creating the directory: /home/centos/firesim-new/deploy/results-workload/2018-05-19--00-38-52-br-base/
[172.30.2.174] Executing task 'instance_liveness'
[172.30.2.174] Checking if host instance is up...
[172.30.2.174] Executing task 'boot_simulation_wrapper'
[172.30.2.174] Starting FPGA simulation for slot: 0.
[172.30.2.174] Executing task 'monitor_jobs_wrapper'

If you don’t look quickly, you might miss it, since it will get replaced with a live status page:

FireSim Simulation Status @ 2018-05-19 00:38:56.062737
--------------------------------------------------------------------------------
This workload's output is located in:
/home/centos/firesim-new/deploy/results-workload/2018-05-19--00-38-52-br-base/
This run's log is located in:
/home/centos/firesim-new/deploy/logs/2018-05-19--00-38-52-runworkload-JS5IGTV166X169DZ.log
This status will update every 10s.
--------------------------------------------------------------------------------
Instances
--------------------------------------------------------------------------------
Hostname/IP:   172.30.2.174 | Terminated: False
--------------------------------------------------------------------------------
Simulated Switches
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Simulated Nodes/Jobs
--------------------------------------------------------------------------------
Hostname/IP:   172.30.2.174 | Job: br-base0 | Sim running: True
--------------------------------------------------------------------------------
Summary
--------------------------------------------------------------------------------
1/1 instances are still running.
1/1 simulations are still running.
--------------------------------------------------------------------------------

This will only exit once all of the simulated nodes have shut down. So, let’s let it run and open another ssh connection to the manager instance. From there, cd into your firesim directory again and source sourceme-manager.sh again to get our ssh key set up. To access our simulated system, ssh into the IP address being printed by the status page, from your manager instance. In our case, from the above output, we see that our simulated system is running on the instance with IP 172.30.2.174. So, run:

[RUN THIS ON YOUR MANAGER INSTANCE!]
ssh 172.30.2.174

This will log you into the instance running the simulation. Then, to attach to the console of the simulated system, run:

screen -r fsim0

Voila! You should now see Linux booting on the simulated system and then be prompted with a Linux login prompt, like so:

[truncated Linux boot output]
[    0.020000] VFS: Mounted root (ext2 filesystem) on device 254:0.
[    0.020000] devtmpfs: mounted
[    0.020000] Freeing unused kernel memory: 140K
[    0.020000] This architecture does not have kernel memory protection.
mount: mounting sysfs on /sys failed: No such device
Starting logging: OK
Starting mdev...
mdev: /sys/dev: No such file or directory
modprobe: can't change directory to '/lib/modules': No such file or directory
Initializing random number generator... done.
Starting network: ip: SIOCGIFFLAGS: No such device
ip: can't find device 'eth0'
FAIL
Starting dropbear sshd: OK

Welcome to Buildroot
buildroot login:

You can ignore the messages about the network – that is expected because we are simulating a design without a NIC.

Now, you can login to the system! The username is root and there is no password. At this point, you should be presented with a regular console, where you can type commands into the simulation and run programs. For example:

Welcome to Buildroot
buildroot login: root
Password:
# uname -a
Linux buildroot 4.15.0-rc6-31580-g9c3074b5c2cd #1 SMP Thu May 17 22:28:35 UTC 2018 riscv64 GNU/Linux
#

At this point, you can run workloads as you’d like. To finish off this guide, let’s poweroff the simulated system and see what the manager does. To do so, in the console of the simulated system, run poweroff -f:

Welcome to Buildroot
buildroot login: root
Password:
# uname -a
Linux buildroot 4.15.0-rc6-31580-g9c3074b5c2cd #1 SMP Thu May 17 22:28:35 UTC 2018 riscv64 GNU/Linux
# poweroff -f

You should see output like the following from the simulation console:

# poweroff -f
[   12.456000] reboot: Power down
Power off
time elapsed: 468.8 s, simulation speed = 88.50 MHz
*** PASSED *** after 41492621244 cycles
Runs 41492621244 cycles
[PASS] FireSim Test
SEED: 1526690334
Script done, file is uartlog

[screen is terminating]

You’ll also notice that the manager polling loop exited! You’ll see output like this from the manager:

FireSim Simulation Status @ 2018-05-19 00:46:50.075885
--------------------------------------------------------------------------------
This workload's output is located in:
/home/centos/firesim-new/deploy/results-workload/2018-05-19--00-38-52-br-base/
This run's log is located in:
/home/centos/firesim-new/deploy/logs/2018-05-19--00-38-52-runworkload-JS5IGTV166X169DZ.log
This status will update every 10s.
--------------------------------------------------------------------------------
Instances
--------------------------------------------------------------------------------
Hostname/IP:   172.30.2.174 | Terminated: False
--------------------------------------------------------------------------------
Simulated Switches
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Simulated Nodes/Jobs
--------------------------------------------------------------------------------
Hostname/IP:   172.30.2.174 | Job: br-base0 | Sim running: False
--------------------------------------------------------------------------------
Summary
--------------------------------------------------------------------------------
1/1 instances are still running.
0/1 simulations are still running.
--------------------------------------------------------------------------------
FireSim Simulation Exited Successfully. See results in:
/home/centos/firesim-new/deploy/results-workload/2018-05-19--00-38-52-br-base/
The full log of this run is:
/home/centos/firesim-new/deploy/logs/2018-05-19--00-38-52-runworkload-JS5IGTV166X169DZ.log

If you take a look at the workload output directory given in the manager output (in this case, /home/centos/firesim-new/deploy/results-workload/2018-05-19--00-38-52-br-base/), you’ll see the following:

centos@ip-172-30-2-111.us-west-2.compute.internal:~/firesim-new/deploy/results-workload/2018-05-19--00-38-52-br-base$ ls -la */*
-rw-rw-r-- 1 centos centos  797 May 19 00:46 br-base0/memory_stats.csv
-rw-rw-r-- 1 centos centos  125 May 19 00:46 br-base0/os-release
-rw-rw-r-- 1 centos centos 7316 May 19 00:46 br-base0/uartlog

What are these files? They are specified to the manager in a configuration file (deploy/workloads/br-base-uniform.json) as files that we want automatically copied back to our manager after we run a simulation, which is useful for running benchmarks automatically. The [DEPRECATED] Defining Custom Workloads section describes this process in detail.

For now, let’s wrap-up our guide by terminating the f1.2xlarge instance that we launched. To do so, run:

firesim terminaterunfarm -a ${CY_DIR}/sims/firesim-staging/sample_config_hwdb.yaml -r ${CY_DIR}/sims/firesim-staging/sample_config_build_recipes.yaml

Which should present you with the following:

FireSim Manager. Docs: http://docs.fires.im
Running: terminaterunfarm

IMPORTANT!: This will terminate the following instances:
f1.16xlarges
[]
f1.4xlarges
[]
m4.16xlarges
[]
f1.2xlarges
['i-0d6c29ac507139163']
Type yes, then press enter, to continue. Otherwise, the operation will be cancelled.

You must type yes then hit enter here to have your instances terminated. Once you do so, you will see:

[ truncated output from above ]
Type yes, then press enter, to continue. Otherwise, the operation will be cancelled.
yes
Instances terminated. Please confirm in your AWS Management Console.
The full log of this run is:
/home/centos/firesim-new/deploy/logs/2018-05-19--00-51-54-terminaterunfarm-T9ZAED3LJUQQ3K0N.log

At this point, you should always confirm in your AWS management console that the instance is in the shutting-down or terminated states. You are ultimately responsible for ensuring that your instances are terminated appropriately.

Congratulations on running your first FireSim simulation! At this point, you can check-out some of the advanced features of FireSim in the sidebar to the left, or you can continue on with the cluster simulation guide.