v++ General Options - 2024.1 English

The v++ command supports many options for the compilation, linking, and packaging processes as described below.

platform=xilinx_u50_gen3x16_xdma_5_202210_1

--advanced

Applies to

Compile, Link, Package

Specify parameters and properties for use by the v++ command. See --advanced Options for more information.

--board_connection

Applies to

Link

--board_connection

Specifies a dual in-line memory module (DIMM) board file for each DIMM connector slot. The board is specified using the Vendor:Board:Name:Version (vbnv) attribute of the DIMM card as it appears in the board repository.

For example:

<DIMM_connector>:<vbnv_of_DIMM_board>

-c | --compile

Applies to

Compile

--compile

Required for compilation, but mutually exclusive with --link and --package. Run v++ -c to generate XO files from kernel source files.

--clock

Applies to

Link

Provide a method for assigning clocks to kernels during the linking process. See --clock Options for more information.

--config

Applies to

Compile, Link, Package

--config <config_file> ...

Specifies a configuration file containing v++ command options. The configuration file can be used to capture compilation, linking, or packaging strategies, that can be easily reused by referring to the config file on the v++ command line. In addition, the config file allows the v++ command line to be shortened to include only the options that are not specified in the config file. Refer to the Vitis Compiler Configuration File for more information.

v++ -l --config system.cfg --config vivado.cfg ...

--connectivity

Applies to

Link

Used to specify important architectural details of the device binary during the linking process. See --connectivity Options for more information.

--custom_script

Applies to

Compile, Link

--custom_script <kernel_name>:<file_name>

This option lets you specify custom Tcl scripts to be used in the build process during compilation or linking. Use with the --export_script option to create, edit, and run the scripts to customize the build process.

When used with the v++ --compile command, this option lets you specify a custom HLS script to be used when compiling the specified kernel. The script lets you modify or customize the Vitis HLS tool. Use the --export_script option to extract a Tcl script Vitis HLS uses to compile the kernel, modify the script as needed, and resubmit using the --custom_script option to better manage the kernel build process.

v++ -c -k kernel1 -export_script ...
*** Modify the exported script to customize in some way, then resubmit. ****
v++ -c --custom_script kernel1:./kernel1.tcl ...

When used with the v++ --link command for the hardware build target (-t hw), this option lets you specify the absolute path to an edited run_script_map.dat file. This file contains a list of steps in the build process, and Tcl scripts that are run by the Vitis and AMD Vivado™ tools during those steps. You can edit run_script_map.dat to specify custom Tcl scripts to run at those steps in the build process. You must use the following steps to customize the Tcl scripts:

1. Run the build process specifying the --export_script option as follows:

   v++ -t hw -l -k kernel1 -export_script ...

2. Copy the Tcl scripts referenced in the run_script_map.dat file for any of the steps you want to customize. For example, copy the Tcl file specified for the synthesis run, or the implementation run. You must copy the file to a separate location, outside of the project build structure.
3. Edit the Tcl script to add or modify any of the existing commands to create a new custom Tcl script.
4. Edit the run_script_map.dat file to point a specific implementation step to the new custom script.
5. Relaunch the build process using the --custom_script option, specifying the absolute path to the run_script_map.dat file as shown below:

   v++ -t hw -l -k kernel1 -custom_script /path/to/run_script_map.dat

read_xdc dont_touch.xdc
set_property used_in_implementation false [get_files dont_touch.xdc]

--debug

Applies to

Link

Specify the addition of debug IP core insertion into the hardware design. See --debug Options for more information.

-D | --define

Applies to

Compile, Link

--define <arg>

Valid macro name and definition pair: <name>=<definition>.

Predefine name as a macro with definition. This option is passed to the v++ preprocessor.

--export_archive

Applies to

Link

--export_archive

This command produces a Vitis metadata archive file (.vma) from the linking process rather than the .xclbin device binary, or .xsa fixed platform. The flow for this command and the use of the .vma file is described in Vitis Export to Vivado Flow.

--export_script

Applies to

Compile, Link, Package

--export_script

This option runs the build process up to the point of exporting a script file, or list of script files, and then stops execution. The build process must be completed using the --custom_script option. This lets you edit the exported script, or list of scripts, and then rerun the build using your custom scripts.

When used with the v++ --compile command, this option exports a Tcl script for the specified kernel, <kernel_name>.tcl, that can be used to execute Vitis HLS, but stops the build process before actually launching the HLS tool. This lets you interrupt the build process to edit the generated Tcl script, and then restart the build process using the --custom_script option, as shown in the following example:

v++ -c -k kernel1 -export_script ...

When used with the v++ --link command for the hardware build target (-t hw), this option exports a run_script_map.dat file in the current directory. This file contains a list of steps in the build process, and Tcl scripts that are run by the Vitis and Vivado tools during those steps. You can edit the specified Tcl scripts, customizing the build process in those scripts, and relaunch the build using the --custom_script option. Export the run_script_map.dat file using the following command:

v++ -l -t hw -export_script ...

--freqhz

Applies to

Compile and Link

--freqhz <value>::<cu>[.<clk_pin>][,<cu_n>[.<clk_pin_n>]]

Specify a frequency for a component during compilation, or for the system during linking. The --freqhz option overrides any default clock frequency and applies the stated frequency during compilation and linking.

Specify a clock frequency in Hertz and a list of associated compute unit names and optionally their clock pins

<value>

Must be specified in Hertz. For example 150 MHz is specified as 150000000

[cu[.clk_pin]]

Optionally specifes a PL kernel or instance of a PL kernel (Compute Unit) target for the specified clock frequency. This lets you specify a different frequency for different instances of kernels. You can also specifythe clock pin of the CU by adding the .clk_pin syntax.

You can add multiple CU and clock pins in a single --freqhz option with a single frequency value specified.

For example:

v++ -l -t hw –platform <pfm_name> --freqhz=200000000:mm2s \
--freqhz=300000000:s2mm –config system.cfg

--from_step

Applies to

Compile, Link, Package

--from_step <arg>

Specifies a step name for the Vitis compiler build process, to start the build process from that step. If intermediate results are available, the link process fast forwards and begins execution at the named step if possible. This allows you to run the build through a --to_step, and then resume the build process at the --from_step, after interacting with your project in some method. You can use the --list_step option to determine the list of valid steps.

For example:

v++ --link --from_step vpl.update_bd

-g

Applies to

Compile, Link

-g

Generates code for debugging the kernel during hardware emulation. Using this option adds features to facilitate debugging the kernel as it is compiled.

For example:

v++ -g ...

-h | --help

Applies to

Compile, Link, Package

-h

Prints the help contents for the v++ command. For example:

v++ -h

--hls

Applies to

Compile

Specify commands for the Vitis HLS synthesis process during kernel compilation.

-I | --include

Applies to

Compile, Link

--include <arg>

Add the specified directory to the list of directories to be searched for header files. This option is passed to the Vitis compiler pre-processor.

--input_files <input_file>

Applies to

Compile, Link, Package

--input_files <input_file1> <input_file2> ...

Specifies an OpenCL or C/C++ kernel source file for v++ compilation, or Xilinx object (XO) files for v++ linking.

For example:

v++ -l --input_files kernel1.xo kernelRTL.xo ...

v++ -l kernel1.xo kernelRTL.xo ...

--interactive

Applies to

Link

--interactive [ impl ]

v++ configures the needed environment and launches the Vivado tool with the implementation project.

Because you are interactively launching the Vivado tool, the linking process is stopped after the vpl step, which is the equivalent of using the --to_step vpl option in your v++ command.

When you are done interactively working with the Vivado tool, and you save the design checkpoint (DCP), you can resume the Vitis compiler linking process using the v++ --from_step rtdgen, or use the --reuse_impl or --reuse_bit options to read in the implemented DCP file or bitstream.

For example:

v++ --interactive impl
## Interactively use the Vivado tool
v++ --from_step rtdgen

-k | --kernel

Applies to

Compile

--kernel <arg>

Compile only the specified kernel from the input file. Only one -k option is allowed per v++ command. Valid values include the name of the kernel to be compiled from the input .cl or .c/.cpp kernel source code.

This is required for C/C++ kernels, but is optional for OpenCL kernels. OpenCL uses the kernel keyword to identify a kernel. For C/C++ kernels, you must identify the kernel by -k or --kernel.

When an OpenCL source file is compiled without the -k option, all the kernels in the file are compiled. Use -k to target a specific kernel.

For example:

v++ -c --kernel vadd

--kernel_frequency

Applies to

Link

--kernel_frequency <freq> | <clockID>:<freq>[<clockID>:<freq>]

Specifies a user-defined clock frequency (in MHz) for the kernel, overriding the default clock frequency defined on the hardware platform. The <freq> specifies a single frequency for kernels with only a single clock, or can be used to specify the <clockID> and the <freq> for kernels that support two clocks.

The syntax for overriding the clock on a platform with only one kernel clock, is to simply specify the frequency in MHz:

v++ --kernel_frequency 300

To override a specific clock on a platform with two clocks, specify the clock ID and frequency:

v++ --kernel_frequency 0:300

To override both clocks on a multi-clock platform, specify each clock ID and the corresponding frequency. For example:

v++ --kernel_frequency 0:300|1:500

-l | --link

Applies to

Link

--link

This is a required option for the linking process, which follows compilation, but is mutually exclusive with --compile or --package. Run v++ in link mode to link XO input files and generate an xclbin or and .xsa output file.

--linkhook

Applies to

Link

Lets you customize the build process for the device binary by specifying Tcl scripts to be run at specific steps in the implementation flow. See --linkhook Options for more information.

--list_steps

Applies to

Compile, Link, Package

--list_steps

List valid run steps for a given target. This option returns a list of steps that can be used in the --from_step or --to_step options. The command must be specified with the following options:

• -t | --target [sw_emu | hw_emu | hw ]:
• [ --compile | --link ]: Specifies the list of steps from either the compile or link process for the specified build target.

For example:

v++ -t hw_emu --link --list_steps

--log_dir

Applies to

Compile, Link, Package

--log_dir <dir_name>

Specifies a directory to store log files into. If --log_dir is not specified, the tool saves the log files to ./_x/logs. Refer to Output Directories of the v++ Command for more information.

For example:

v++ --log_dir /tmp/myProj_logs ...

--message_rules

Applies to

Compile, Link, Package

--message-rules <file_name>

Specifies a message rule file with rules for controlling messages. Refer to Using the Message Rule File for more information.

For example:

v++ --message_rules ./minimum_out.mrf ...

--mode

Applies to

Compile

Specifies a compilation mode for the v++ command, with accepted values being aie or hls. The v++ --mode aie creates an AI Engine component as described in AI Engine Tools and Flows User Guide (UG1076), and can be used with confiuration commands described under v++ Mode AI Engine. The v++ --mode hls creates an HLS component as described in Vitis HLS User Guide (UG1399), and can be used with configuration file commands described in v++ Mode HLS.

--no_ip_cache

Applies to

Link

--no_ip_cache

Disables the IP cache for out-of-context (OOC) synthesis for Vivado Synthesis. Disabling the IP cache repository requires the tool to regenerate the IP synthesis results for every build, and can increase the build time. However, it also results in a clean build, eliminating earlier results for IP in the design.

For example:

v++ --no_ip_cache ...

-O | --optimize

Applies to

Link

--optimize <arg>

This option specifies the optimization level of the Vivado implementation results. Valid optimization values include the following:

• 0: Default optimization. Reduces compilation time.
• 1: Optimizes to reduce power consumption by running Vivado implementation strategy Power_DefaultOpt. This takes more time to build the design.
• 2: Optimizes to increase kernel speed. This option increases build time, but also improves the performance of the generated kernel by adding the PHYS_OPT_DESIGN step to implementation.
• 3: This optimization provides the highest level performance in the generated code, but compilation time can increase considerably. This option specifies retiming during synthesis, and enables both PHYS_OPT_DESIGN and POST_ROUTE_PHYS_OPT_DESIGN during implementation.
• s: Optimizes the design for size. This reduces the logic resources of the device used by the kernel by running the Area_Explore implementation strategy.
• quick: Reduces Vivado implementation time, but can reduce kernel performance, and increases the resources used by the kernel. This enables the Flow_RuntimeOptimized strategy for both synthesis and implementation.

For example:

v++ --link --optimize 2

-o | --output

Applies to

Compile, Link, Package

-o <output_name>

Specifies the name of the output file generated by the v++ command. The compilation (-c) process output name must end with the XO file suffix, for Xilinx object file. The linking (-l) process output file must end with the .xclbin file suffix, or .xsa suffix. The --export_archive command requires the .vma suffix. The --package command takes the .xsa as input and outputs the .xclbin.

For example:

v++ -o krnl_vadd.xo

If --o or --output are not specified, the output file names default to the following:

Compilation

a.o

Linking

a.xclbin (a.xsa for Versal platforms)

Packaging

a.xclbin

-p | --package

Applies to

Package

Specify options for the Vitis compiler to package your design for either running emulation or running on hardware. See --package Options for more information.

--part

Applies to

Compile, Link, Package

--part <part_name>

Specifies an AMD part for use in compiling, linking, and packaging the components of your design. The --part command can be used to specify a device rather than a full platform or XSA. Specifying v++ --link --part <Versal part only> instructs the tools to generate a simple base hardware platform for the specified AMD Versal™ device.

For example:

v++ --part xcvc1902-vsva2197-2MP-e-S --target hw_emu ...

-f | --platform

Applies to

Compile, Link, Package

--platform <platform_name>

Specifies the name of a supported acceleration platform as specified by the $PLATFORM_REPO_PATHS environment variable, or the full path to the platform .xpfm file. For a list of supported platforms for the release, see the Vitis Software Platform Release Notes.

This is a required option for both compilation and linking, to define the target AMD platform of the build process. The --platform option accepts either a platform name, or the path to a platform file xpfm, using the full or relative path.

For example:

v++ --platform xilinx_u50_gen3x16_xdma_5_202210_1 ...

--profile

Applies to

Compile, Link

Specify options to configure the Xilinx Runtime environment to capture application performance information. See --profile Options for more information.

--remote_ip_cache

Applies to

Link

--remote_ip_cache <dir_name>

Specifies the location of the remote IP cache directory for Vivado Synthesis to use during out-of-context (OOC) synthesis of IP. OOC synthesis lets the Vivado synthesis tool reuse synthesis results for IP that have not been changed in iterations of a design. This can reduce the time required to build your .xclbin files, due to reusing synthesis results.

When the --remote_ip_cache option is not specified the IP cache is written to the current working directory from which v++ was launched. You can use this option to provide a different cache location, used across multiple projects for instance.

For example:

v++ --remote_ip_cache /tmp/IP_cache_dir ...

--report_dir

Applies to

Compile, Link, Package

--report_dir <dir_name>

Specifies a directory to store report files into. If --report_dir is not specified, the tool saves the report files to ./_x/reports. Refer to Output Directories of the v++ Command for more information.

For example:

v++ --report_dir /tmp/myProj_reports ...

-R | --report_level

Applies to

Compile, Link, Package

--report_level <arg>

Valid report levels: 0, 1, 2, estimate.

These report levels have mappings kept in the optMap.xml file. You can override the installed optMap.xml to define custom report levels.

• -R0 specification turns off all intermediate design checkpoint (DCP) generation during Vivado implementation. Turns on post-route timing report generation.
• The -R1 specification includes everything from -R0, plus report_failfast pre-opt_design, report_failfast post-opt_design, and enables all intermediate DCP generation.
• The -R2 specification includes everything from -R1, plus report_failfast post-route_design.
• The -Restimate specification forces Vitis HLS to generate a design.xml file if it does not exist and then generates a System Estimate report, as described in System Estimate Report.

For example:

v++ -R2 ... 

--reuse_bit

--reuse_bit <arg>

Applies to

Link

Specifies the path and file name of generated bitstream file (.bit) to use when generating the device binary (xclbin) file. As described in Using --to_step and Launching Vivado Interactively, you can specify the --to_step option to interrupt the Vitis build process and manually place and route a synthesized design to generate the bitstream.

For example:

v++ --link --reuse_bit ./project.bit

--reuse_impl

--reuse_impl <arg>

Applies to

Link

Specifies the path and file name of an implemented design checkpoint (DCP) file to use when generating the device binary (xclbin) file. The link process uses the specified implemented DCP to extract the FPGA bitstream and generates the xclbin. You can manually edit theVivado project created by a previously completed Vitis build, or specify the --to_step option to interrupt the Vitis build process and manually place and route a synthesized design, for instance. This allows you to work interactively with Vivado Design Suite to change the design and use DCP in the build process.

For example:

v++ --link --reuse_impl ./manual_design.dcp

-s | --save-temps

Applies to

Compile, Link, Package

--save-temps

Directs the v++ command to save intermediate files/directories created during the compilation and link process. Use the --temp_dir option to specify a location to write the intermediate files to.

For example:

v++ --save-temps ...

-t | --target

Applies to

Compile, Link, Package

-t [ sw_emu | hw_emu | hw ]

Specifies the build target, as described in Working with Build Targets. The build target determines the results of the compilation and linking processes. You can choose to build an emulation model for debug and test, or build the actual system to run in hardware. The build target defaults to hw if -t is not specified.

The valid values are:

• hw_emu: Hardware emulation
• hw: Hardware

For example:

v++ --link -t hw_emu

--temp_dir

Applies to

Compile, Link, Package

--temp_dir <dir_name>

This allows you to manage the location where the tool writes temporary files created during the build process. The temporary results are written by the v++ compiler, and then removed, unless the --save-temps option is also specified.

If --temp_dir is not specified, the tool saves the temporary files to ./_x/temp. Refer to Output Directories of the v++ Command for more information.

For example:

v++ --temp_dir /tmp/myProj_temp ...

--to_step

Applies to

Compile, Link, Package

--to_step <arg>

Specifies a step name, for either the compile or link process, to run the build process through that step. You can use the --list_step option to determine the list of valid compile or link steps.

The build process terminates after completing the named step. At this time, you can interact with the build results. For example, manually accessing the HLS project or the Vivado Design Suite project to perform specific tasks before returning to the build flow, launch the v++ command with the --from_step option.

You must also specify --save-temps when using --to_step to preserve the temporary files required by the Vivado tools. For example:

v++ --link --save-temps --to_step vpl.update_bd

--user_board_repo_paths

Applies to

Link

--user_board_repo_paths

Specifies an existing user board repository for DIMM board files. This value is pre-pended to the board_part_repo_paths property of the Vivado project.

--user_ip_repo_paths

Applies to

Link

--user_ip_repo_paths <repo_dir>

Specifies the directory location of one or more user IP repository paths to be searched first for IP used in the kernel design. This value is appended to the start of the ip_repo_paths used by the Vivado tool to locate IP cores. IP definitions from these specified paths are used ahead of IP repositories from the hardware platform (.xsa) or from the AMD IP catalog.

The following lists show the priority order in which IP definitions are found during the build process, from high to low.

• For the system hardware build (-t hw):
  1. IP definitions from --user_ip_repo_paths.
  2. Kernel IP definitions (vpl --iprepo switch value).
  3. IP definitions from the IP repository associated with the platform.
  4. IP cache from the installation area (for example, <Install_Dir>/Vitis/2019.2/data/cache/).
  5. AMD IP catalog from the installation area (for example, <Install_Dir>/Vitis/2019.2/data/ip/)
• For the hardware emulation build (-t hw_emu):
  1. IP definitions and User emulation IP repository from --user_ip_repo_paths.
  2. Kernel IP definitions (vpl --iprepo switch value).
  3. IP definitions from the IP repository associated with the platform.
  4. IP cache from the installation area (for example, <Install_Dir>/Vitis/2019.2/data/cache/).
  5. $::env(XILINX_VITIS)/data/emulation/hw_em/ip_repo
  6. $::env(XILINX_VIVADO)/data/emulation/hw_em/ip_repo
  7. AMD IP catalog from the installation area (for example, <Install_Dir>/Vitis/2019.2/data/ip/)

For example:

v++ --user_ip_repo_paths ./myIP_repo ...

-v | --version

-v

Prints the version and build information for the v++ command. For example:

v++ -v

--vivado

Applies to

Link

Specify properties and parameters to configure the Vivado synthesis and implementation environment prior to building the device binary. See --vivado Options for more information.