HDL_workflow/symbiflow.mdwn

   1 # Installation instructions for Symbiflow with Xilinx Artix7 100T Board
   2
   3 * <https://symbiflow.github.io/>
   4 * <https://github.com/SymbiFlow>
   5
   6 ## Bugzilla page
   7
   8 * <https://bugs.libre-soc.org/show_bug.cgi?id=654>
   9
  10 ## Setting up new debootstrap and chroot into it
  11
  12 Run the following if you wish to isolate the symbiflow build
  13 from other software (reproducible builds) or use the schroot
  14 auto-preparation script here:
  15 <https://git.libre-soc.org/?p=dev-env-setup.git;a=blob;f=mk-deb-chroot;hb=HEAD>
  16
  17     export MY_CHROOT=/stable-chroot
  18     mkdir $MY_CHROOT
  19     debootstrap buster $MY_CHROOT http://deb.debian.org/debian/
  20     mount -t proc proc $MY_CHROOT/proc
  21     mount -t sysfs sysfs $MY_CHROOT/sys
  22     mount -t devpts devpts $MY_CHROOT/dev/pts/
  23     chroot $MY_CHROOT /bin/bash
  24
  25 ## Add Buster Backports Repo and Update
  26
  27 ""buster backports is needed for cmake""
  28
  29     cat << EOF > /etc/apt/sources.list.d/buster_backports.list
  30     deb http://deb.debian.org/debian buster-backports main
  31     EOF
  32
  33 ""oooo annoying, pin preferences for buster-backports""
  34
  35     cat << EOF > /etc/apt/preferences.d/99buster-backports
  36     Package: *
  37     Pin: release a=buster-backports
  38     Pin-Priority: 900
  39     EOF
  40
  41 ""upgrade to buster-backports""
  42
  43     apt-get update -y
  44     apt-get upgrade -y
  45
  46
  47 ## Download neccessary softwares
  48
  49     apt-get install -y libcurl3-gnutls/buster git/buster wget
  50
  51     git clone https://github.com/steveicarus/iverilog.git
  52     git clone https://github.com/YosysHQ/yosys.git
  53     git clone https://github.com/YosysHQ/abc.git
  54     git clone https://github.com/oneapi-src/oneTBB.git
  55     git clone https://github.com/verilog-to-routing/vtr-verilog-to-routing.git
  56     git clone https://github.com/cliffordwolf/icestorm.git
  57     git clone https://github.com/SymbiFlow/prjxray.git
  58     git clone https://github.com/SymbiFlow/prjxray-db.git
  59     git clone https://github.com/SymbiFlow/yosys-symbiflow-plugins.git
  60     git clone https://github.com/SymbiFlow/symbiflow-examples.git
  61     git clone https://github.com/SymbiFlow/symbiflow-arch-defs.git
  62     git clone https://github.com/QuickLogic-Corp/quicklogic-fasm.git
  63     git clone https://github.com/QuickLogic-Corp/quicklogic-fasm-utils.git
  64     git clone https://github.com/SymbiFlow/python-fpga-interchange.git
  65     git clone https://github.com/capnproto/capnproto.git
  66     git clone https://github.com/capnproto/pycapnp.git
  67
  68     wget http://xmlsoft.org/sources/libxml2-2.9.12.tar.gz
  69     wget http://xmlsoft.org/sources/libxslt-1.1.34.tar.gz
  70
  71 ## Steps to compile Icarus Verilog
  72
  73 ### Necessary software to install
  74
  75     apt-get install -y build-essential autoconf make g++ bison flex gperf \
  76       libreadline6-dev
  77
  78 ### Build Icarus Verilog
  79
  80     cd iverilog
  81     git checkout v11_0
  82     sh autoconf.sh
  83     ./configure --prefix=/usr/local/symbiflow/iverilog
  84     make -j$(nproc)
  85     make check
  86     make install
  87     export PATH=/usr/local/symbiflow/iverilog/bin:$PATH
  88     cd ..
  89
  90 ## Steps to compile Yosys
  91
  92 ### Necessary software to install
  93
  94     apt-get install -y cmake
  95     apt-get install -y python3 clang libreadline-dev gawk tcl-dev \
  96     libffi-dev pkg-config libboost-system-dev libboost-python-dev \
  97     libboost-filesystem-dev zlib1g-dev
  98
  99 ### Build Yosys
 100
 101     cd abc
 102     git checkout 4f5f73d18b137930fb3048c0b385c82fa078db38
 103     cd ../yosys
 104     git checkout f44110c62561b21fa673f44d8e115c3ee70d2900
 105     ln -s ../abc .
 106     make -j $(nproc) PREFIX=/usr/local/symbiflow/yosys
 107     make PREFIX=/usr/local/symbiflow/yosys install
 108     install -d -m 0755 /usr/local/symbiflow/share
 109     ln -s ../yosys/share/yosys /usr/local/symbiflow/share
 110     export PATH=/usr/local/symbiflow/yosys/bin:$PATH
 111     cd ..
 112
 113 ## Steps to compile oneTBB
 114
 115 * Note: TBB is needed for multi-threading VTR-Verilog-to-routing
 116 * If not need multi-threading do not build TBB and VTR with TBB
 117
 118 ### Necessary software to install
 119
 120     apt-get install -y libhwloc-dev
 121
 122 ### Build TBB
 123
 124     cd oneTBB
 125     git checkout v2020.3
 126     make -j$(nproc) tbb tbbmalloc tbbproxy tbbbind
 127     install -d -m 0755 /usr/local/symbiflow/oneTBB/lib
 128     cp -dpr include /usr/local/symbiflow/oneTBB
 129     install -Dm755 build/linux_*/*.so* -t /usr/local/symbiflow/oneTBB/lib
 130     cmake -DINSTALL_DIR=/usr/local/symbiflow/oneTBB/lib/cmake/TBB \
 131       -DTBB_VERSION_FILE=/usr/local/symbiflow/oneTBB/include/tbb/tbb_stddef.h \
 132       -DSYSTEM_NAME=Linux -P cmake/tbb_config_installer.cmake
 133     echo "/usr/local/symbiflow/oneTBB/lib" > /etc/ld.so.conf.d/symbiflow.conf
 134     ldconfig
 135     cd ..
 136
 137 ## Steps to compile vtr-verilog-to-routing
 138
 139 ### Necessary software to install
 140
 141     apt-get install -y libeigen3-dev
 142
 143     # Only if want GUI place and route
 144     #apt-get install libcairo2-dev libfontconfig1-dev libx11-dev libxft-dev \
 145     #libgtk-3-dev
 146
 147 ### Build vtr
 148
 149     cd vtr-verilog-to-routing
 150     git checkout 77a3df829fdf509a76b9d7b941376f3835c2576a
 151     mkdir build; cd build
 152     cmake -DCMAKE_INSTALL_PREFIX=/usr/local/symbiflow/vtr ..
 153     make -j $(nproc)
 154     make install
 155     install -d -m 0755 /usr/local/symbiflow/share/vtr
 156     install -m 0644 ../libs/libvtrcapnproto/gen/rr_graph_uxsdcxx.capnp \
 157       /usr/local/symbiflow/share/vtr
 158     export PATH=/usr/local/symbiflow/vtr/bin:$PATH
 159     cd ../..
 160
 161 ### Build vtr-tbb
 162
 163     cd vtr-verilog-to-routing
 164     git checkout 77a3df829fdf509a76b9d7b941376f3835c2576a
 165     mkdir build-tbb; cd build-tbb
 166     cmake -DCMAKE_INSTALL_PREFIX=/usr/local/symbiflow/vtr-tbb \
 167       -DTBB_INCLUDE_DIR=/usr/local/symbiflow/oneTBB/include \
 168       -DTBB_LIBRARY=/usr/local/symbiflow/oneTBB/lib -DBUILD_TYPE=Release ..
 169     LIBRARY_PATH=/usr/local/symbiflow/oneTBB/lib make -j $(nproc)
 170     LIBRARY_PATH=/usr/local/symbiflow/oneTBB/lib make install
 171     install -d -m 0755 /usr/local/symbiflow/share/vtr
 172     install -m 0644 ../libs/libvtrcapnproto/gen/rr_graph_uxsdcxx.capnp \
 173       /usr/local/symbiflow/share/vtr
 174     # Choose either one of path for vtr-binaries
 175     # This one or above one
 176     #export PATH=/usr/local/symbiflow/vtr-tbb/bin:$PATH
 177     cd ../..
 178
 179 ## Steps to compile libxml2
 180
 181 * Newer version is needed which fixes a integer overflow error and is not
 182   provided by Buster.
 183
 184 ### Necessary software to install
 185
 186     apt-get install -y python3-dev
 187
 188 ### Build libxml2
 189
 190     tar -xf libxml2-2.9.12.tar.gz
 191     cd libxml2-2.9.12
 192     ./configure --prefix=/usr/local/symbiflow/libxml2 --with-history \
 193       --with-python=/usr/bin/python3
 194     make -j $(nproc)
 195     make install
 196     echo "/usr/local/symbiflow/libxml2/lib" >> /etc/ld.so.conf.d/symbiflow.conf
 197     ldconfig
 198     export PATH=/usr/local/symbiflow/libxml2/bin:$PATH
 199     cd ..
 200
 201 ## Steps to compile libxslt
 202
 203 * Needed by python3 lxml
 204
 205 ### Build libxslt
 206
 207     tar -xf libxslt-1.1.34.tar.gz
 208     cd libxslt-1.1.34
 209     sed -i s/3000/5000/ libxslt/transform.c doc/xsltproc.{1,xml}
 210     sed -i -r '/max(Parser)?Depth/d' ./tests/fuzz/fuzz.c
 211     ./configure --prefix=/usr/local/symbiflow/libxslt --disable-static \
 212       --without-python \
 213        PKG_CONFIG_PATH=/usr/local/symbiflow/libxml2/lib/pkgconfig
 214     make -j $(nproc)
 215     make install
 216     echo "/usr/local/symbiflow/libxslt/lib" >> /etc/ld.so.conf.d/symbiflow.conf
 217     ldconfig
 218     export PATH=/usr/local/symbiflow/libxslt/bin:$PATH
 219     cd ..
 220
 221 ## Steps to compile prjxray
 222
 223 ### Necessary software to install
 224
 225 ### Build prjxray
 226
 227     cd prjxray
 228     git checkout f7f06896ad26bb7c94680dc323d4b871eded1f4e
 229     git submodule update --init --recursive
 230     mkdir build; cd build
 231     cmake -DCMAKE_INSTALL_PREFIX=/usr/local/symbiflow ..
 232     make -j$(nproc)
 233     make install
 234     export PATH=/usr/local/symbiflow/bin:$PATH
 235     cd ../..
 236
 237 ## Steps to compile yosys-symbiflow-plugins
 238
 239 ### Necessary software to install
 240
 241 ### Build yosys-symbiflow-plugins
 242
 243     cd yosys-symbiflow-plugins
 244     git checkout b170f1d3575568d87901422f846b700169e299be
 245     sed -i -e 's@-include third_party/make-env/conda.mk@#-include third_party/make-env/conda.mk@' Makefile
 246     make -j$(nproc)
 247     make install
 248     cd ..
 249
 250 ## Steps to compile prjxray-db
 251
 252 ### Install prjxray-db
 253
 254     cd prjxray-db
 255     git archive --format=tar --prefix=prjxray-db/ \
 256       cd41f08a8a4d2a60053750a0fe10623b1e2e35da | \
 257       tar -C /usr/local/symbiflow -xf -
 258
 259     cat > /usr/local/symbiflow/bin/prjxray-config << EOF
 260     #!/bin/bash
 261     echo /usr/local/symbiflow/prjxray-db
 262     EOF
 263
 264     chmod +x /usr/local/symbiflow/bin/prjxray-config
 265     cd ..
 266
 267 ## Steps to compile Icestorm
 268
 269 ### Necessary software to install
 270
 271     apt-get install -y libftdi-dev
 272
 273 ### Build Icestorm
 274
 275     cd icestorm
 276     git checkout 83b8ef947f77723f602b706eac16281e37de278c
 277     make -j $(nproc) PREFIX=/usr/local/symbiflow/icestorm
 278     make PREFIX=/usr/local/symbiflow/icestorm install
 279     export PATH=/usr/local/symbiflow/icestorm/bin:$PATH
 280     cd ..
 281
 282 ## Steps to compile capnproto
 283
 284 ### Necessary software to install
 285
 286     apt-get install -y automake autoconf libtool
 287
 288 ### Build capnproto
 289
 290     cd capnproto
 291     git checkout v0.8.0
 292     cd c++
 293     autoreconf -i
 294     ./configure --prefix=/usr/local/symbiflow/capnproto
 295     make -j $(nproc)
 296     make install
 297     echo "/usr/local/symbiflow/capnproto/lib" >> /etc/ld.so.conf.d/symbiflow.conf
 298     ldconfig
 299     export PATH=/usr/local/symbiflow/capnproto/bin:$PATH
 300     cd ../..
 301
 302 ## Steps to compile pycapnp
 303
 304 ### Necessary software to install
 305
 306     apt-get install -y python3-pip cython3
 307
 308 ### Build pycapnp
 309
 310     cd pycapnp
 311     git checkout v1.0.0b1
 312     pip3 install .
 313     cd ..
 314
 315 ##  Git checkout python-fpga-interchange
 316
 317     cd python-fpga-interchange
 318     git checkout 1959b40e998db987c604c0a75664ccb209df13f7
 319     cd ..
 320
 321 ##  Git checkout quicklogic-fasm-utils
 322
 323     cd quicklogic-fasm-utils
 324     git checkout 3d6a375ddb6b55aaa5a59d99e44a207d4c18709f
 325     cd ..
 326
 327 ##  Git checkout quicklogic-fasm
 328
 329     cd quicklogic-fasm
 330     git checkout ee546ff09b2ee25894db3f419366afaf3c4bfe32
 331     cd ..
 332
 333 ## Steps to compile symbiflow-arch-defs
 334
 335 ## Necessary software to install
 336
 337     apt-get install -y nodejs npm python-pytest openocd flake8 python3-numpy \
 338       python3-intervaltree python3-simplejson python3-intelhex \
 339       python3-importlib-metadata python3-jsonschema python3-packaging \
 340       python3-pyparsing python3-pyrsistent python3-tqdm python3-zipp \
 341       python3-typing-extensions python3-ply
 342
 343     pip3 install textx fasm pyjson5 pyyaml tinyfpgab tinyprog pyjson lxml \
 344       progressbar2 hilbertcurve==1.0.5 python-constraint parameterized \
 345       yapf==0.26.0 python-sat
 346
 347 ### Build symbiflow
 348
 349     cd symbiflow-arch-defs
 350     git checkout c2c0f00960baf538eb31e4c42bf5d09dca87bad7
 351     git submodule init
 352     git submodule update --init --recursive
 353     pip3 install ../python-fpga-interchange
 354     pip3 install -e third_party/prjxray
 355     pip3 install -e third_party/xc-fasm
 356     pip3 install ../quicklogic-fasm-utils
 357     pip3 install ../quicklogic-fasm
 358     pip3 install -e third_party/qlf-fasm
 359     pip3 install -e quicklogic/common/utils/quicklogic-timings-importer
 360     pip3 install -e third_party/vtr-xml-utils
 361     pip3 install -e third_party/python-symbiflow-v2x
 362     pip3 install -e third_party/python-sdf-timing
 363     pip3 install -e third_party/symbiflow-xc-fasm2bels
 364
 365     mkdir -p env/conda/envs
 366     ln -s /usr/local/symbiflow env/conda/envs/symbiflow_arch_def_base
 367
 368     sed -i -e 's@add_subdirectory(litex)@#add_subdirectory(litex)@g' \
 369       -e 's@add_subdirectory(ibex)@#add_subdirectory(ibex)@g' \
 370       xc/xc7/tests/soc/CMakeLists.txt
 371
 372 ### Build symbiflow-arch-defs-xc7-artix7-100t
 373
 374     export VPR_NUM_WORKERS=$(nproc)
 375
 376     mkdir build; cd build
 377     cmake -DUSE_CONDA=FALSE -DPRJXRAY_DB_DIR=/usr/local/symbiflow/prjxray-db \
 378       -DINSTALL_FAMILIES=xc7 -DINSTALL_ARCHS=artix7_100t \
 379       -DINSTALL_DEVICES=xc7a100t -DCMAKE_INSTALL_PREFIX=/usr/local/symbiflow ..
 380     cd xc/xc7/archs/artix7_100t
 381     make install
 382     cd ../..
 383     make PINMAP_INSTALL_arty100t-full_xc7a100t_test_arty100t-full_pinmap.csv
 384     install -d -m 0755 /usr/local/symbiflow/share/symbiflow/arch/xc7a100t_test/xc7a100tcsg324-1
 385     install -m 0644 arty100t-full_pinmap.csv /usr/local/symbiflow/share/symbiflow/arch/xc7a100t_test/xc7a100tcsg324-1/pinmap.csv
 386
 387     # Now you can skip to symbiflow-examples.git for external test
 388
 389     # To do builtin counter test; it should build top.bit as final bitstream
 390     cd tests/counter
 391     make counter_arty100t_bit
 392
 393     # see file counter_arty100t/artix7_100t-xc7a100t-virt-xc7a100t-test/top.bit
 394     # it is the bitstream file and if built then success
 395
 396     cd ../../../../..
 397
 398 ### Build symbiflow-arch-defs-xc7-artix7 (xc7a50t)
 399
 400 "If you do not want this target skip"
 401
 402     export VPR_NUM_WORKERS=$(nproc)
 403
 404     mkdir build_artix7; cd build_artix7
 405     cmake -DUSE_CONDA=FALSE -DPRJXRAY_DB_DIR=/usr/local/symbiflow/prjxray-db \
 406       -DINSTALL_FAMILIES=xc7 -DINSTALL_ARCHS=artix7_100t \
 407       -DINSTALL_DEVICES=xc7a50t \
 408       -DCMAKE_INSTALL_PREFIX=/usr/local/symbiflow ..
 409     cd xc/xc7/archs/artix7
 410     make install
 411     cd ../..
 412     make PINMAP_INSTALL_arty-full_xc7a50t_test_arty-full_pinmap.csv
 413     install -d -m 0755 /usr/local/symbiflow/share/symbiflow/arch/xc7a50t_test/xc7a50tfgg484-1
 414     install -m 0644 arty-full_pinmap.csv /usr/local/symbiflow/share/symbiflow/arch/xc7a50t_test/xc7a50tfgg484-1/pinmap.csv
 415     install -d -m 0755 /usr/local/symbiflow/share/symbiflow/arch/xc7a50t_test/xc7a35tcsg324-1
 416     ln -s ../xc7a50tfgg484-1/pinmap.csv /usr/local/symbiflow/share/symbiflow/arch/xc7a50t_test/xc7a35tcsg324-1
 417
 418     # Now you can skip to symbiflow-examples.git for external test
 419
 420     # To do builtin counter test; it should build top.bit as final bitstream
 421     cd tests/counter
 422     make counter_arty100t_bit
 423
 424     # see file counter_arty/artix7-xc7a50t-arty-swbut-roi-virt-xc7a50t-arty-swbut-test/top.bit
 425     # it is the bitstream file and if built then success
 426
 427     cd ../../../../../..
 428
 429 ## Steps to compile symbiflow-examples
 430
 431 ### Build counter test for arty_100
 432
 433     cd symbiflow-examples
 434     git checkout 07a6353627e0b6083728d1022ce30f9093d4c2de
 435
 436     cd xc7
 437     TARGET="arty_100" make -C counter_test
 438
 439     # Should produce top.bit bitstream
 440     # see file counter_test/build/arty_100/top.bit
 441
 442 ### Build counter test for arty_35
 443
 444     TARGET="arty_35" make -C counter_test
 445
 446     # Should produce top.bit bitstream
 447     # see file counter_test/build/arty_/top.bit
 448
 449 ### Build picosoc demo for arty_100
 450
 451     TARGET="arty_100" make -C picosoc_demo
 452
 453     # Should produce top.bit bitstream
 454     # see file picosoc_demo/build/arty_100/top.bit
 455
 456 ### Build picosoc demo for arty_35
 457
 458     TARGET="arty_35" make -C picosoc_demo
 459
 460     # Should produce top.bit bitstream
 461     # see file picosoc_demo/build/arty_35/top.bit
 462
 463 ### Build Linux Litex Demo for arty_100
 464
 465     TARGET="arty_100" make -C linux_litex_demo
 466
 467     # Should produce top.bit bitstream
 468     # see file linux_litex_demo/build/arty_100/top.bit
 469
 470 ### Build Linux Litex Demo for arty_35
 471
 472     TARGET="arty_35" make -C linux_litex_demo
 473
 474     # Should produce top.bit bitstream
 475     # see file linux_litex_demo/build/arty_35/top.bit
 476
 477     cd ../..
 478
 479 ## Steps to compile symbiflow-examples Litex
 480
 481 ### Get Litex
 482
 483     mkdir litex
 484     cd litex
 485
 486     git clone https://github.com/m-labs/migen
 487     git clone https://github.com/litex-hub/pythondata-software-compiler_rt
 488     git clone https://github.com/enjoy-digital/litex
 489     git clone https://github.com/enjoy-digital/litedram
 490     git clone https://github.com/enjoy-digital/liteeth
 491     git clone https://github.com/enjoy-digital/liteiclink
 492     git clone https://github.com/enjoy-digital/litesdcard
 493     git clone https://github.com/litex-hub/litespi
 494     git clone https://github.com/litex-hub/litex-boards
 495     git clone https://github.com/litex-hub/pythondata-cpu-picorv32
 496     git clone https://github.com/litex-hub/pythondata-cpu-vexriscv
 497     git clone https://github.com/litex-hub/pythondata-software-picolibc.git
 498
 499 ### Build Litex
 500
 501 "Git Commits"
 502
 503     migen=6e3f8e565704b4293174aedfb15b3470d233f528
 504     pythondata-software-compiler_rt=fcb03245613ccf3079cc833a701f13d0beaae09d
 505     litex=db20cb172dc982c5879aa8080ec7aa18de181cc5
 506     litedram=1d5192f572c2eb97bc85eb56667e25dc88d725f1
 507     liteeth=8ecc3ca6d9476dd1a8b32b2b6bf3584cd6dcfc02
 508     liteiclink=3d8ecdbcf9f0260292221ff63b0ad3f5e409a955
 509     litesdcard=4edf05e627a8b5f03e632215accec8ab588737e3
 510     litespi=4cb907881bb75999e4c6bb68e211dd5cfc301de9
 511     litex-boards=9e18d9bc34bafb18839512a55dc66ba62e0d4824
 512     pythondata-cpu-picorv32=2e8be513726fb6ffd960f7e18d24e3a86d895107
 513     pythondata-cpu-vexriscv=c4eca1837ebca20b637a0a61e3a93d9446488459
 514     pythondata-software-picolibc=e27c8a7ef8a8e75b6474823aae338efb1a2ca1a9
 515
 516     for pkg in migen pythondata-software-compiler_rt litex litedram \
 517                liteeth liteiclink litesdcard litespi litex-boards \
 518                pythondata-cpu-picorv32 pythondata-cpu-vexriscv \
 519                pythondata-software-picolibc; do
 520      cd "$pkg"
 521      eval git checkout $`echo $pkg`
 522      pip3 install -e .
 523      cd ..
 524     done
 525
 526 #### Build Litex Demo
 527
 528     cd litex-boards
 529
 530     # Arty 100T Picorv32
 531     ./litex_boards/targets/digilent_arty.py --toolchain=symbiflow \
 532       --cpu-type=picorv32 --sys-clk-freq 80e6 --variant a7-100 \
 533       --output-dir build/picorv32/arty_100 --build --no-compile-software
 534     # see file build/picorv32/arty_100/gateware/digilent_arty.bit
 535     # this is the built bitstream
 536
 537     # Arty 100T VexRiscv
 538
 539     ./litex_boards/targets/digilent_arty.py --toolchain=symbiflow \
 540       --cpu-type=vexriscv --sys-clk-freq 80e6 --variant a7-100 \
 541       --output-dir build/vexriscv/arty_100 --build --no-compile-software
 542     # see file build/vexriscv/arty_100/gateware/digilent_arty.bit
 543     # this is the built bitstream
 544
 545     # Arty 35T Picorv32
 546
 547     ./litex_boards/targets/digilent_arty.py --toolchain=symbiflow \
 548       --cpu-type=picorv32 --sys-clk-freq 80e6 --variant a7-35 \
 549       --output-dir build/picorv32/arty_35 --build --no-compile-software
 550     # see file build/picorv32/arty_35/gateware/digilent_arty.bit
 551     # this is the built bitstream
 552
 553     # Arty 35T VexRiscv
 554
 555     ./litex_boards/targets/digilent_arty.py --toolchain=symbiflow \
 556       --cpu-type=vexriscv --sys-clk-freq 80e6 --variant a7-35 \
 557       --output-dir build/vexriscv/arty_35 --build --no-compile-software
 558     # see file build/vexriscv/arty_35/gateware/digilent_arty.bit
 559     # this is the built bitstream
 560