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3rd Party

This section is for more advanced users that want to build LiveHD with some external 3rd party tool.

When integrating LiveHD with a 3rd party tool (nextpnr in this example), you can either bring the 3rd party tool to LiveHD and hence build it with bazel, or you can export the LiveHD code/libraries and integrate with the 3rd party project. This document covers the later case.

Requirements

Bazel pulls a specific set of library dependences, if you export, you must ensure that the 3rd party tool uses the same library version. The 3 main source of likely conflict is "boost", "abseil", and "fmt". The "fmt" library is unlikely to be a conflict because LiveHD uses it as "header" only to avoid conflicts with other tools like slang.

To check the boost and abseil version, the easiest way: 

bazel build -c dbg //main:all
# boost version 1.71 in this case
grep -i "define BOOST_VERSION " bazel-*/external/boost//boost/version.hpp
#define BOOST_VERSION 107100

# abseil version 20210324
grep "define ABSL_OPTION_INLINE_NAMESPACE_NAME" bazel-*/external/com_google_absl/absl/base/options.h
#define ABSL_OPTION_INLINE_NAMESPACE_NAME lts_20210324

nextpnr example

nextpnr uses boost, in the previous example, you need to compile it with boost 1.71, with the usual requirements:

# nextpnr ice40 needs icestorm, so install it first
git clone https://github.com/cliffordwolf/icestorm.git
cd icestorm
make
sudo make install

# compile nextpnr itself
git clone https://github.com/YosysHQ/nextpnr.git
cd nextpnr
mkdir build
cd build
cmake -DARCH=ice40 ../
make -j $(ncpus)

The previous steps should compile before you attempt to integrate LiveHD to nextpnr.

Then, you need to clone and compile LiveHD. If you clone and compile parallel to nextpnr

git clone https://github.com/masc-ucsc/livehd.git
cd livehd
bazel build -c dbg //main:all  # You could use -c opt for faster/optimized compilation
cd ../nextpnr/build/
ln -s ../../livehd/
ln -s livehd/bazel-out
ln -s livehd/bazel-livehd

Then, we need to copy the bazel gcc build instructions and combine with the nextpnr build

Copy this to a file called pp: 

--- livehd.params   2021-09-25 17:47:36.656724997 -0700
+++ livehd.params   2021-09-25 17:40:24.365650808 -0700
@@ -1,16 +1,17 @@
--o
-bazel-out/k8-dbg/bin/main/lgshell
+-std=c++17
+-Wno-unknown-pragmas
+-I livehd/eprp -I livehd/elab -I bazel-livehd/external/com_google_absl -I bazel-livehd/external/fmt/include/ -I bazel-livehd/external/iassert/src -I livehd/mmap_lib/include -I livehd/core -I livehd/task -I livehd/lemu -I ./bazel-livehd/external/rapidjson -I livehd/pass/common -I ./bazel-livehd/external/replxx/include
+./extra.cpp
 -pie
 -fuse-ld=gold
 -Wl,-no-as-needed
 -Wl,-z,relro,-z,now
 -B/usr/bin
 -pass-exit-codes
 -lstdc++
 -lm
-bazel-out/k8-dbg/bin/main/_objs/lgshell/main.pic.o
 -Wl,--start-lib
 bazel-out/k8-dbg/bin/main/_objs/main/inou_lef_api.pic.o
 bazel-out/k8-dbg/bin/main/_objs/main/main_api.pic.o
 bazel-out/k8-dbg/bin/main/_objs/main/meta_api.pic.o
 bazel-out/k8-dbg/bin/main/_objs/main/top_api.pic.o

The patch adds a new c++ file to compile (extra.cpp). It will be nicer if the file is in the nextpnr directory structure, but this is as an example of how to integrate. extra.cpp has a call to LiveHD to open a database as example.

cp livehd/bazel-bin/main/lgshell-2.params livehd.params
patch <pp

This example uses extra.cpp as a sample LiveHD call inside nextpnr. The extra.cpp contents:

#include "lgraph.hpp"

void some_func() {
  Lgraph *lg = Lgraph::open("lgdb","top");

  lg->dump();
}

Then you need to add the @livehd.params to the end of the nextpnr-ice40 link step. A way to get the command line is to use the VERBOSE=1 option.

rm -f nextpnr-ice40
make VERBOSE=1 nextpnr-ice40

Cut and paste the command, it will end with something like thon3.9.so @livehd.params to be something like: 

/usr/bin/c++ -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers -Wno-array-bounds -fPIC -O3 -g -pipe -flto -fno-fat-lto-objects CMakeFiles/nextpnr-ice40.dir/common/archcheck.cc.o CMakeFiles/nextpnr-ice40.dir/common/basectx.cc.o CMakeFiles/nextpnr-ice40.dir/common/bits.cc.o CMakeFiles/nextpnr-ice40.dir/common/command.cc.o CMakeFiles/nextpnr-ice40.dir/common/context.cc.o CMakeFiles/nextpnr-ice40.dir/common/design_utils.cc.o CMakeFiles/nextpnr-ice40.dir/common/embed.cc.o CMakeFiles/nextpnr-ice40.dir/common/handle_error.cc.o CMakeFiles/nextpnr-ice40.dir/common/idstring.cc.o CMakeFiles/nextpnr-ice40.dir/common/idstringlist.cc.o CMakeFiles/nextpnr-ice40.dir/common/log.cc.o CMakeFiles/nextpnr-ice40.dir/common/nextpnr.cc.o CMakeFiles/nextpnr-ice40.dir/common/nextpnr_assertions.cc.o CMakeFiles/nextpnr-ice40.dir/common/nextpnr_namespaces.cc.o CMakeFiles/nextpnr-ice40.dir/common/nextpnr_types.cc.o CMakeFiles/nextpnr-ice40.dir/common/place_common.cc.o CMakeFiles/nextpnr-ice40.dir/common/placer1.cc.o CMakeFiles/nextpnr-ice40.dir/common/placer_heap.cc.o CMakeFiles/nextpnr-ice40.dir/common/property.cc.o CMakeFiles/nextpnr-ice40.dir/common/pybindings.cc.o CMakeFiles/nextpnr-ice40.dir/common/report.cc.o CMakeFiles/nextpnr-ice40.dir/common/router1.cc.o CMakeFiles/nextpnr-ice40.dir/common/router2.cc.o CMakeFiles/nextpnr-ice40.dir/common/sdf.cc.o CMakeFiles/nextpnr-ice40.dir/common/str_ring_buffer.cc.o CMakeFiles/nextpnr-ice40.dir/common/svg.cc.o CMakeFiles/nextpnr-ice40.dir/common/timing.cc.o CMakeFiles/nextpnr-ice40.dir/common/timing_opt.cc.o CMakeFiles/nextpnr-ice40.dir/3rdparty/json11/json11.cpp.o CMakeFiles/nextpnr-ice40.dir/json/jsonwrite.cc.o CMakeFiles/nextpnr-ice40.dir/frontend/json_frontend.cc.o CMakeFiles/nextpnr-ice40.dir/ice40/arch.cc.o CMakeFiles/nextpnr-ice40.dir/ice40/arch_place.cc.o CMakeFiles/nextpnr-ice40.dir/ice40/arch_pybindings.cc.o CMakeFiles/nextpnr-ice40.dir/ice40/bitstream.cc.o CMakeFiles/nextpnr-ice40.dir/ice40/cells.cc.o CMakeFiles/nextpnr-ice40.dir/ice40/chains.cc.o CMakeFiles/nextpnr-ice40.dir/ice40/delay.cc.o CMakeFiles/nextpnr-ice40.dir/ice40/gfx.cc.o CMakeFiles/nextpnr-ice40.dir/ice40/main.cc.o CMakeFiles/nextpnr-ice40.dir/ice40/pack.cc.o CMakeFiles/nextpnr-ice40.dir/ice40/pcf.cc.o CMakeFiles/chipdb-ice40.dir/ice40/chipdb/chipdb-384.cc.o CMakeFiles/chipdb-ice40.dir/ice40/chipdb/chipdb-1k.cc.o CMakeFiles/chipdb-ice40.dir/ice40/chipdb/chipdb-5k.cc.o CMakeFiles/chipdb-ice40.dir/ice40/chipdb/chipdb-u4k.cc.o CMakeFiles/chipdb-ice40.dir/ice40/chipdb/chipdb-8k.cc.o -o nextpnr-ice40  -ltbb /usr/lib/x86_64-linux-gnu/libboost_filesystem.so /usr/lib/x86_64-linux-gnu/libboost_program_options.so /usr/lib/x86_64-linux-gnu/libboost_iostreams.so /usr/lib/x86_64-linux-gnu/libboost_system.so /usr/lib/x86_64-linux-gnu/libboost_thread.so -lpthread /usr/lib/x86_64-linux-gnu/libboost_regex.so /usr/lib/x86_64-linux-gnu/libboost_chrono.so /usr/lib/x86_64-linux-gnu/libboost_date_time.so /usr/lib/x86_64-linux-gnu/libboost_atomic.so -lpthread /usr/lib/x86_64-linux-gnu/libpython3.9.so @livehd.params

You can check that the new binary includes liveHD with something like: 

nm nextpnr-ice40 | grep -i Lgraph