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Alveo U200 to AWS F1 Migration Example

This example illustrates how to port a Vitis application developed for an Alveo U200 card to an AWS EC2 F1 instance.

The Vitis development flow provides platform independent APIs and interfaces to the developer. This greatly facilitates the process of migrating applications across similar FPGA acceleration cards. In this example, the source code for the software program and for the FPGA kernels remains unchanged. Only command line changes are necessary to port the application from Alveo U200 to AWS F1.

Example Overview

The accelerator used in this example is a simple vector-add kernel. The src directory contains the source code for the project:

  • vadd.cpp contains the C++ source code of the accelerator which adds 2 arbitrarily sized input vectors.
  • host.cpp contains the main function running on the host CPU. The host application is written in C++ and uses OpenCL™ APIs to interact with the FPGA accelerator.

The u200 and f1 directories contain the Makefiles and scripts for building for Alveo U200 and AWS F1 respectively.

Building for Alveo U200

Note: The instructions below assume that the required tools and platforms are installed and that the environment is properly setup to run Vitis.

  1. Go to the u200 directory

  2. The example is built with the following commands:

    g++ -D__USE_XOPEN2K8 -I/$XILINX_XRT/include/ -I./src -O3 -Wall -fmessage-length=0 -std=c++11 ../src/host.cpp -L/$XILINX_XRT/lib/ -lxilinxopencl -lpthread -lrt -o host

v++ -c -g -t hw -R 1 -k vadd --config ./options.cfg --profile_kernel data:all:all:all --profile_kernel stall:all:all:all --save-temps --temp_dir ./temp_dir --report_dir ./report_dir --log_dir ./log_dir -I../src ../src/vadd.cpp -o ./vadd.hw.xo

v++ -l -g -t hw -R 1 --config ./options.cfg --profile_kernel data:all:all:all --profile_kernel stall:all:all:all --temp_dir ./temp_dir --report_dir ./report_dir --log_dir ./log_dir -I../src vadd.hw.xo -o add.hw.xclbin
    • The g++ command compiles the host program and links it with the Xilinx Runtime (XRT) libraries. XRT provides platform-independent APIs to interact with the FPGA, allowing the source code to remain the same for U200 and F1.
    • The v++ -c command compiles the source code for vector-add kernel (vadd.cpp) and generates the compiled kernel object (.xo).
    • The v++ -l command links the compiled kernel to the shell and produces the FPGA binary (.xclbin file) which can then be loaded on the U200 acceleration card.

  3. For both v++commands, the --config option is used to pass the name of a file called options.cfg containing additional options specific to building for U200. The options.cfg file contains the following options:

    platform=xilinx_u200_xdma_201830_2
[connectivity]
sp=vadd_1.in1:DDR[1]
sp=vadd_1.in2:DDR[1]
sp=vadd_1.out:DDR[1]
    • The platform option specifies which acceleration platform is targeted for the build. Here we are using the U200 shell.
    • The sp options are used to specify the assignment of kernel arguments to DDR banks. In this case, we are mapping all three kernel arguments to DDR[1], which is the DDR interface located in the shell on Alveo U200.

    Putting all the platform-specific options in one file is not mandatory but it is very convenient and facilitates the porting process. With this approach, the main command line can be reused as is for all platforms. Refer to the Vitis Documentation for more information on v++ related commands and options.

  4. The Makefile provided in the directory can be used to build the project for U200. Running make build will build the host application, compile the kernel and finally create the FPGA binary for U200.

Building for AWS F1

In order to port the vector-add example from Alveo U200 to AWS F1, the only change required is in the options.cfg file. The source code remains unchanged and the g++ and v++ commands remain identical.

  1. Go to the f1 directory

  2. The options.cfg file for AWS F1 contains the following options:

    platform=xilinx_aws-vu9p-f1_shell-v04261818_201920_2
[connectivity]
sp=vadd_1.in1:DDR[0]
sp=vadd_1.in2:DDR[0]
sp=vadd_1.out:DDR[0]
    • The platform option is set to target the AWS F1 shell. The string used corresponds to the name of the latest shell which can be found here on the aws-fpga repo.
    • The sp options are set to connect the kernel arguments to DDR[0], which is the DDR interface located in the AWS F1 shell. Keeping the same settings as the U200 would produce a working design on AWS F1. But in order to produce exactly the same configuration and target the DDR interface located in the AWS F1 shell, the sp options are modified to use DDR[0].

    These changes are the only ones needed to port this project from U200 to F1.

  3. You can build the project for AWS F1 using the exact same commands that were used for U200:

    export PLATFORM_REPO_PATHS=/home/centos/src/project_data/aws-fpga/Vitis/aws_platform

g++ -D__USE_XOPEN2K8 -I/$XILINX_XRT/include/ -I./src -O3 -Wall -fmessage-length=0 -std=c++11 ../src/host.cpp -L/$XILINX_XRT/lib/ -lxilinxopencl -lpthread -lrt -o host

v++ -c -g -t hw -R 1 -k vadd --config ./options.cfg --profile_kernel data:all:all:all --profile_kernel stall:all:all:all --save-temps --temp_dir ./temp_dir --report_dir ./report_dir --log_dir ./log_dir -I../src ../src/vadd.cpp -o ./vadd.hw.xo

v++ -l -g -t hw -R 1 --config ./options.cfg --profile_kernel data:all:all:all --profile_kernel stall:all:all:all --temp_dir ./temp_dir --report_dir ./report_dir --log_dir ./log_dir -I../src vadd.hw.xo -o add.hw.xclbin

    NOTE: The PLATFORM_REPO_PATHS environment variable is used to specify the directory where the AWS platform (xilinx_aws-vu9p-f1_shell-v04261818_201920_2) is installed.

  4. When targeting AWS F1, you need to go through the additional step of creating an Amazon FPGA Image (AFI). This is done with the create_vitis_afi.sh command provided by AWS. More information about this command is available on the AWS documentation.

    Use the command below to generate the AFI and the .awsxclbin file:

    $AWS_FPGA_REPO_DIR/Vitis/tools/create_vitis_afi.sh -xclbin=./vadd.xclbin -o=./vadd -s3_bucket=<bucket-name> -s3_dcp_key=f1-dcp-folder -s3_logs_key=f1-logs

    NOTE: Make sure to use your S3 bucket information when running the create_vitis_afi command.

    Check the status of the AFI creation process by using the AFI ID with the follow command:

    aws ec2 describe-fpga-images --fpga-image-ids <AFI ID>

    The AFI is ready to use when the state is reported as 'available'.

        "State":  {
        "Code": "available" 
    },

    NOTE: The AFI ID can be found in the _afi_id.txt file created by the create_vitis_afi command.

Running the Application on AWS F1

  1. Execute the following command to source the Vitis runtime environment

    source $AWS_FPGA_REPO_DIR/vitis_runtime_setup.sh

  2. Execute the host application with the .awsxclbin FPGA binary

    ./host vadd.awsxclbin

  3. The messages below will indicate that the program ran successfully.

    Found Platform
Platform Name: Xilinx
INFO: Reading ./vadd.awsxclbin
Loading: './vadd.awsxclbin'
TEST PASSED

Summary

In the Vitis flow, the user can develop source code which remains mostly agnostic of platform-specific platform details. This greatly facilitates the process of migrating applications across similar FPGA acceleration cards. In this example, the same source code could be ported from Alveo U200 to AWS F1 without any changes at all. Only a couple of changes to the v++ compilation options were required.

For a complete application migration checklist, refer to the Migration between Alveo U200 platform & Amazon EC2 F1 instances application note.