diff --git a/.bazelignore b/.bazelignore
new file mode 100644
index 00000000..92b27930
--- /dev/null
+++ b/.bazelignore
@@ -0,0 +1 @@
+.direnv
diff --git a/.gitignore b/.gitignore
index cd7fc45f..4251ea81 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,15 @@
+<<<<<<< Updated upstream
+=======
+# Misc
+/.direnv
+/.envrc
+
+# Bazel
+MODULE.bazel.lock
+bazel-*
+
+/generated/
+>>>>>>> Stashed changes
 /objs/
 /nextpnr-generic*
 /nextpnr-ice40*
diff --git a/BUILD b/BUILD
new file mode 100644
index 00000000..1166caa5
--- /dev/null
+++ b/BUILD
@@ -0,0 +1,539 @@
+# Copyright 2020 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+""" BUILD file for nextpnr. Does currently not include the GUI. """
+
+load("@rules_cc//cc:defs.bzl", "cc_binary", "cc_library", "cc_test")
+load("@rules_python//python:defs.bzl", "py_binary")
+load("@pybind11_bazel//:build_defs.bzl", "pybind_library")
+
+package(
+    features = [
+        "-use_header_modules",  # For exceptions.
+    ],
+)
+
+licenses(["notice"])
+
+exports_files(["LICENSE"])
+
+DEFINES = [
+    "NO_GUI",
+    "NO_RUST",
+]
+
+FAMILIES = [
+    "generic",
+    "ice40",
+    "ecp5",
+]
+
+BBASM_ENDIAN_FLAG = "--le"
+
+genrule(
+    name = "version_h",
+    srcs = ["common/version.h.in"],
+    outs = ["common/version.h"],
+    cmd = "cat $(SRCS) | sed 's/@CURRENT_GIT_VERSION@/0.8.0-18c7b40/g' > $@",
+)
+
+cc_binary(
+    name = "bbasm",
+    srcs = ["bba/main.cc"],
+    deps = [
+        "@boost.filesystem",
+        "@boost.program_options",
+    ],
+)
+
+COMMON_KERNEL_SRCS = [
+    "common/kernel/sdc.cc",
+    "common/kernel/timing.cc",
+    "common/kernel/bits.cc",
+    "common/kernel/command.cc",
+    "common/kernel/design_utils.cc",
+    "common/kernel/log.cc",
+    "common/kernel/context.cc",
+    "common/kernel/nextpnr_types.cc",
+    "common/kernel/nextpnr_assertions.cc",
+    "common/kernel/pybindings.cc",
+    "common/kernel/nextpnr.cc",
+    "common/kernel/basectx.cc",
+    "common/kernel/embed.cc",
+    "common/kernel/report.cc",
+    "common/kernel/sdf.cc",
+    "common/kernel/idstring.cc",
+    "common/kernel/property.cc",
+    "common/kernel/str_ring_buffer.cc",
+    "common/kernel/nextpnr_namespaces.cc",
+    "common/kernel/idstringlist.cc",
+    "common/kernel/timing_log.cc",
+    "common/kernel/svg.cc",
+    "common/kernel/handle_error.cc",
+    "common/kernel/archcheck.cc",
+]
+
+COMMON_KERNEL_HDRS = [
+    "common/kernel/basectx.h",
+    "common/kernel/pybindings.h",
+    "common/kernel/nextpnr_base_types.h",
+    "common/kernel/sso_array.h",
+    "common/kernel/nextpnr_types.h",
+    "common/kernel/base_clusterinfo.h",
+    "common/kernel/base_arch.h",
+    "common/kernel/nextpnr_namespaces.h",
+    "common/kernel/bits.h",
+    "common/kernel/log.h",
+    "common/kernel/scope_lock.h",
+    "common/kernel/idstring.h",
+    "common/kernel/deterministic_rng.h",
+    "common/kernel/nextpnr_assertions.h",
+    "common/kernel/exclusive_state_groups.impl.h",
+    "common/kernel/relptr.h",
+    "common/kernel/embed.h",
+    "common/kernel/nextpnr.h",
+    "common/kernel/constraints.h",
+    "common/kernel/indexed_store.h",
+    "common/kernel/arch_pybindings_shared.h",
+    "common/kernel/constraints.impl.h",
+    "common/kernel/chain_utils.h",
+    "common/kernel/hashlib.h",
+    "common/kernel/pycontainers.h",
+    "common/kernel/dynamic_bitarray.h",
+    "common/kernel/context.h",
+    "common/kernel/property.h",
+    "common/kernel/design_utils.h",
+    "common/kernel/idstringlist.h",
+    "common/kernel/pywrappers.h",
+    "common/kernel/timing.h",
+    "common/kernel/command.h",
+    "common/kernel/arch_api.h",
+    "common/kernel/array2d.h",
+    "common/kernel/str_ring_buffer.h",
+    "common/kernel/exclusive_state_groups.h",
+    "common/kernel/util.h",
+]
+
+COMMON_ROUTE_SRCS = [
+    "common/route/router2.cc",
+    "common/route/router1.cc",
+]
+
+COMMON_ROUTE_HDRS = [
+    "common/route/router2.h",
+    "common/route/router1.h",
+]
+
+COMMON_PLACE_SRCS = [
+    "common/place/placer1.cc",
+    "common/place/place_common.cc",
+    "common/place/detail_place_core.cc",
+    "common/place/placer_heap.cc",
+    "common/place/placer_static.cc",
+    "common/place/parallel_refine.cc",
+    "common/place/timing_opt.cc",
+]
+
+COMMON_PLACE_HDRS = [
+    "common/place/detail_place_core.h",
+    "common/place/parallel_refine.h",
+    "common/place/placer_static.h",
+    "common/place/timing_opt.h",
+    "common/place/fast_bels.h",
+    "common/place/placer1.h",
+    "common/place/placer_heap.h",
+    "common/place/detail_place_cfg.h",
+    "common/place/place_common.h",
+    "common/place/static_util.h",
+]
+
+JSON_SRCS = [
+    "json/jsonwrite.cc",
+]
+
+JSON_HDRS = [
+    "json/jsonwrite.h",
+]
+
+FRONTEND_SRCS = [
+    "frontend/json_frontend.cc",
+]
+
+FRONTEND_HDRS = [
+    "frontend/frontend_base.h",
+    "frontend/json_frontend.h",
+]
+
+FFTSG_SRCS = [
+    "3rdparty/oourafft/fftsg.cc",
+    "3rdparty/oourafft/fftsg2d.cc",
+]
+
+FFTSG_HDRS = [
+    "3rdparty/oourafft/fftsg.h",
+]
+
+CORE_SRCS = COMMON_KERNEL_SRCS \
+    + COMMON_ROUTE_SRCS \
+    + COMMON_PLACE_SRCS \
+    + JSON_SRCS \
+    + FRONTEND_SRCS \
+    + FFTSG_SRCS
+
+CORE_HDRS = COMMON_KERNEL_HDRS \
+    + COMMON_ROUTE_HDRS \
+    + COMMON_PLACE_HDRS \
+    + JSON_HDRS \
+    + FRONTEND_HDRS \
+    + FFTSG_HDRS \
+    + [
+        "rust/rust.h",
+        "common/version.h",
+    ]
+
+ICE40_DEFINES = [
+    "NEXTPNR_NAMESPACE=nextpnr_ice40",
+    "ARCH_ICE40",
+    "ARCHNAME=ice40",
+]
+
+ICE40_DEVICES = [
+    "384",
+    "1k",
+    "5k",
+    "u4k",
+    "8k",
+]
+
+ICE40_CHIPDB_OPTS = {
+    "384": ' '.join([
+        "--slow $(location @icestorm//:icefuzz/timings_lp384.txt)"
+    ]),
+    "1k":  ' '.join([
+        "--fast $(location @icestorm//:icefuzz/timings_hx1k.txt)",
+        "--slow $(location @icestorm//:icefuzz/timings_lp1k.txt)",
+    ]),
+    "5k":  ' '.join([
+        "--slow $(location @icestorm//:icefuzz/timings_up5k.txt)"
+    ]),
+    "u4k": ' '.join([
+        "--slow $(location @icestorm//:icefuzz/timings_u4k.txt)"
+    ]),
+    "8k":  ' '.join([
+        "--fast $(location @icestorm//:icefuzz/timings_hx8k.txt)",
+        " --slow $(location @icestorm//:icefuzz/timings_lp8k.txt)",
+    ]),
+}
+
+py_binary(
+    name = "ice40_chipdb_py",
+    srcs = ["ice40/chipdb.py"],
+    main = "ice40/chipdb.py",
+    python_version = "PY3",
+)
+
+[genrule(
+    name = "ice40_chipdb_%s_bba" % device,
+    srcs = [
+        "ice40/constids.inc",
+        "ice40/gfx.h",
+        "@icestorm//:chipdb-%s.txt" % device,
+        "@icestorm//:icefuzz/timings_lp384.txt",
+        "@icestorm//:icefuzz/timings_hx1k.txt",
+        "@icestorm//:icefuzz/timings_lp1k.txt",
+        "@icestorm//:icefuzz/timings_up5k.txt",
+        "@icestorm//:icefuzz/timings_u4k.txt",
+        "@icestorm//:icefuzz/timings_hx8k.txt",
+        "@icestorm//:icefuzz/timings_lp8k.txt",
+    ],
+    outs = ["generated/ice40_chipdb_%s.bba" % device],
+    cmd = ' '.join([
+        "$(location :ice40_chipdb_py)",
+        "-p $(location ice40/constids.inc)",
+        "-g $(location ice40/gfx.h)",
+        "%s $(location @icestorm//:chipdb-%s.txt) > $@",
+    ]) % (
+        ICE40_CHIPDB_OPTS[device],
+        device,
+    ),
+    tools = [":ice40_chipdb_py"],
+) for device in ICE40_DEVICES]
+
+[genrule(
+    name = "ice40_chipdb_%s_cc" % device,
+    srcs = ["generated/ice40_chipdb_%s.bba" % device],
+    outs = ["generated/ice40_chipdb_%s.cc" % device],
+    cmd = "$(location :bbasm) --c %s $(SRCS) $@" % BBASM_ENDIAN_FLAG,
+    tools = [":bbasm"],
+) for device in ICE40_DEVICES]
+
+ICE40_HDRS = [
+    "ice40/archdefs.h",
+    "ice40/arch.h",
+    "ice40/constids.inc",
+]
+
+cc_library(
+    name = "ice40_chipdb",
+    srcs = [
+        "generated/ice40_chipdb_%s.cc" % device
+        for device in ICE40_DEVICES
+    ] + COMMON_KERNEL_HDRS + ICE40_HDRS,
+    defines = ICE40_DEFINES,
+    includes = [
+        "ice40",
+        "common/kernel",
+    ],
+    deps = [
+        "@boost.functional",
+        "@boost.lexical_cast",
+        "@boost.thread",
+    ],
+)
+
+# The CLI binary target, one for each architecture.
+pybind_library(
+    name = "ice40",
+    srcs = [
+        "ice40/arch.cc",
+        "ice40/archdefs.h",
+        "ice40/arch.h",
+        "ice40/arch_place.cc",
+        "ice40/arch_pybindings.cc",
+        "ice40/arch_pybindings.h",
+        "ice40/bitstream.cc",
+        "ice40/bitstream.h",
+        "ice40/cells.cc",
+        "ice40/cells.h",
+        "ice40/chains.cc",
+        "ice40/chains.h",
+        "ice40/delay.cc",
+        "ice40/gfx.cc",
+        "ice40/gfx.h",
+        "ice40/pack.cc",
+        "ice40/pcf.cc",
+        "ice40/pcf.h",
+        "ice40/constids.inc",
+    ] + CORE_SRCS + CORE_HDRS,
+    cxxopts = [
+        "-std=c++17",
+        "-fexceptions",
+        "-Wno-unused-variable",
+        "-Wno-implicit-conversion-floating-point-to-bool",
+        "-Wno-implicit-fallthrough",
+    ],
+    defines = DEFINES + ICE40_DEFINES,
+    includes = [
+        "common/kernel",
+        "common/route",
+        "common/place",
+        "common",
+        "json",
+        "frontend",
+        "3rdparty/oourafft",
+        "rust",
+    ],
+    linkopts = ["-lpthread"],
+    visibility = ["//visibility:public"],
+    deps = [
+        ":ice40_chipdb",
+        "@eigen",
+        "@json11",
+        "@boost.filesystem",
+        "@boost.algorithm",
+        "@boost.functional",
+        "@boost.lexical_cast",
+        "@boost.thread",
+        "@boost.iostreams",
+        "@boost.program_options",
+        "@boost.system",
+    ],
+)
+
+cc_binary(
+    name = "nextpnr-ice40",
+    srcs = [
+        "ice40/main.cc",
+    ],
+    visibility = ["//visibility:public"],
+    deps = [
+        ":ice40",
+        "@rules_python//python/cc:current_py_cc_libs"
+    ],
+)
+
+cc_test(
+    name = "ice40_test",
+    srcs =  glob([
+        "ice40/tests/*.cc",
+    ]),
+    deps = [
+        ":ice40",
+        "@googletest//:gtest_main",
+        "@rules_python//python/cc:current_py_cc_libs",
+    ],
+)
+
+ECP5_DEFINES = [
+    "NEXTPNR_NAMESPACE=nextpnr_ecp5",
+    "ARCH_ECP5",
+    "ARCHNAME=ecp5",
+]
+
+ECP5_DEVICES = [
+    "25k",
+    "45k",
+    "85k",
+]
+
+py_binary(
+    name = "trellis_import",
+    srcs = ["ecp5/trellis_import.py"],
+    python_version = "PY3",
+    deps = [
+        "@prjtrellis//:prjtrellis",
+    ],
+)
+
+[genrule(
+    name = "ecp5_chipdb_%s_bba" % device,
+    srcs = [
+        "ecp5/constids.inc",
+        "ecp5/gfx.h",
+        "@prjtrellis_db//:devices.json",
+        "@prjtrellis_db//:files",
+    ],
+    outs = ["generated/ecp5_chipdb_%s.bba" % device],
+    cmd = " ".join([
+        "PRJTRELLIS_DB=$$(dirname '$(location @prjtrellis_db//:devices.json)')",
+        "$(location :trellis_import)",
+        "-p $(location ecp5/constids.inc)",
+        "-g $(location ecp5/gfx.h) %s > $@"]) % device,
+    tools = [":trellis_import"],
+) for device in ECP5_DEVICES]
+
+[genrule(
+    name = "ecp5_chipdb_%s_cc" % device,
+    srcs = ["generated/ecp5_chipdb_%s.bba" % device],
+    outs = ["generated/ecp5_chipdb_%s.cc" % device],
+    cmd = "$(location :bbasm) --c %s $(SRCS) $@" % BBASM_ENDIAN_FLAG,
+    tools = [":bbasm"],
+) for device in ECP5_DEVICES]
+
+ECP5_HDRS = [
+    "ecp5/arch.h",
+    "ecp5/config.h",
+    "ecp5/archdefs.h",
+    "ecp5/globals.h",
+    "ecp5/bitstream.h",
+    "ecp5/dcu_bitstream.h",
+    "ecp5/pio.h",
+    "ecp5/cells.h",
+    "ecp5/arch_pybindings.h",
+    "ecp5/gfx.h",
+    "ecp5/constids.inc",
+]
+
+cc_library(
+    name = "ecp5_chipdb",
+    srcs = [
+        "generated/ecp5_chipdb_%s.cc" % device
+        for device in ECP5_DEVICES
+    ] + COMMON_KERNEL_HDRS + ECP5_HDRS,
+    defines = ECP5_DEFINES,
+    includes = [
+        "ecp5",
+        "common/kernel",
+    ],
+    deps = [
+        "@boost.thread",
+    ],
+)
+
+
+# The CLI binary target, one for each architecture.
+pybind_library(
+    name = "ecp5",
+    srcs = [
+        "ecp5/arch.cc",
+        "ecp5/archdefs.h",
+        "ecp5/arch.h",
+        "ecp5/arch_place.cc",
+        "ecp5/arch_pybindings.cc",
+        "ecp5/arch_pybindings.h",
+        "ecp5/baseconfigs.cc",
+        "ecp5/bitstream.cc",
+        "ecp5/bitstream.h",
+        "ecp5/cells.cc",
+        "ecp5/cells.h",
+        "ecp5/config.cc",
+        "ecp5/config.h",
+        "ecp5/constids.inc",
+        "ecp5/dcu_bitstream.h",
+        "ecp5/gfx.cc",
+        "ecp5/gfx.h",
+        "ecp5/globals.cc",
+        "ecp5/globals.h",
+        "ecp5/iotypes.inc",
+        "ecp5/lpf.cc",
+        "ecp5/pack.cc",
+        "ecp5/pio.cc",
+        "ecp5/pio.h",
+    ] + CORE_SRCS + CORE_HDRS,
+    cxxopts = [
+        "-std=c++17",
+        "-fexceptions",
+        "-Wno-unused-variable",
+        "-Wno-implicit-conversion-floating-point-to-bool",
+        "-Wno-implicit-fallthrough",
+    ],
+    defines = DEFINES + ECP5_DEFINES,
+    includes = [
+        "common/kernel",
+        "common/route",
+        "common/place",
+        "common",
+        "json",
+        "frontend",
+        "3rdparty/oourafft",
+        "rust",
+    ],
+    linkopts = ["-lpthread"],
+    visibility = ["//visibility:public"],
+    deps = [
+        ":ecp5_chipdb",
+        "@eigen",
+        "@json11",
+        "@boost.filesystem",
+        "@boost.algorithm",
+        "@boost.functional",
+        "@boost.lexical_cast",
+        "@boost.thread",
+        "@boost.iostreams",
+        "@boost.program_options",
+        "@boost.system",
+    ],
+)
+
+cc_binary(
+    name = "nextpnr-ecp5",
+    srcs = [
+        "ecp5/main.cc",
+    ],
+    visibility = ["//visibility:public"],
+    deps = [
+        ":ecp5",
+        "@rules_python//python/cc:current_py_cc_libs"
+    ],
+)
diff --git a/MODULE.bazel b/MODULE.bazel
new file mode 100644
index 00000000..8475345d
--- /dev/null
+++ b/MODULE.bazel
@@ -0,0 +1,36 @@
+module(
+    name = "nextpnr",
+    version = "0.8.0"
+)
+
+bazel_dep(name = "platforms", version = "0.0.11")
+bazel_dep(name = "rules_cc", version = "0.1.1")
+bazel_dep(name = "rules_python", version = "1.0.0")
+bazel_dep(name = "pybind11_bazel", version = "2.13.6")
+
+bazel_dep(name = "boost.filesystem", version = "1.83.0")
+bazel_dep(name = "boost.iostreams", version = "1.83.0")
+bazel_dep(name = "boost.program_options", version = "1.83.0")
+bazel_dep(name = "boost.system", version = "1.83.0")
+bazel_dep(name = "boost.thread", version = "1.83.0")
+bazel_dep(name = "boost.algorithm", version = "1.83.0")
+bazel_dep(name = "googletest", version = "1.17.0")
+bazel_dep(name = "eigen", version = "4.0.0-20241125.bcr.1")
+bazel_dep(name = "json11", version = "1.0.1-0.20200325232727-2df9473fb360")
+bazel_dep(name = "boost.functional", version = "1.83.0")
+bazel_dep(name = "boost.lexical_cast", version = "1.83.0")
+bazel_dep(name = "prjtrellis", version = "1.4.0")
+bazel_dep(name = "icestorm", version = "0.0.1")
+git_override(
+    module_name = "icestorm",
+    commit = "85fd1682b58581b82d1d14f63c089fb033177c21",
+    remote = "https://github.com/amorphic-io/icestorm.git",
+)
+git_override(
+    module_name = "prjtrellis",
+    commit = "3332d029295a8e424969126f5c61a5ea111882a8",
+    remote = "https://github.com/amorphic-io/prjtrellis.git",
+)
+
+prjtrellis_db = use_extension("@prjtrellis//:extensions.bzl", "prjtrellis_db")
+use_repo(prjtrellis_db, "prjtrellis_db")
diff --git a/ecp5/trellis_import.py b/ecp5/trellis_import.py
index 11b6e94a..1295ad2f 100755
--- a/ecp5/trellis_import.py
+++ b/ecp5/trellis_import.py
@@ -14,7 +14,7 @@ parser = argparse.ArgumentParser(description="import ECP5 routing and bels from
 parser.add_argument("device", type=str, help="target device")
 parser.add_argument("-p", "--constids", type=str, help="path to constids.inc")
 parser.add_argument("-g", "--gfxh", type=str, help="path to gfx.h")
-parser.add_argument("-L", "--libdir", type=str, action="append", help="extra Python library path")
+parser.add_argument("-L", "--libdir", type=str, action="append", default=[], help="extra Python library path")
 args = parser.parse_args()
 
 sys.path += args.libdir
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 00000000..376925ff
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,61 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1743583204,
+        "narHash": "sha256-F7n4+KOIfWrwoQjXrL2wD9RhFYLs2/GGe/MQY1sSdlE=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "2c8d3f48d33929642c1c12cd243df4cc7d2ce434",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "2c8d3f48d33929642c1c12cd243df4cc7d2ce434",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 00000000..f8e8891c
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,169 @@
+{
+  description = "fpga-assembler";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/2c8d3f48d33929642c1c12cd243df4cc7d2ce434";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs =
+    {
+      self,
+      nixpkgs,
+      flake-utils,
+    }@inputs:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = import nixpkgs {
+          inherit system;
+        };
+        common = with pkgs; {
+          bazel = bazel_7;
+          jdk = jdk;
+        };
+      in
+      {
+        devShells.default =
+          let
+            # There is too much volatility between even micro-versions of
+            # newer clang-format. Use slightly older version for now.
+            clang_for_formatting = pkgs.llvmPackages_17.clang-tools;
+
+            # clang tidy: use latest.
+            clang_for_tidy = pkgs.llvmPackages_18.clang-tools;
+          in
+          with pkgs;
+          pkgs.mkShell {
+            packages = with pkgs; [
+              git
+              common.bazel
+              common.jdk
+              bash
+              gdb
+              cmake
+              boost
+              pkg-config
+              eigen
+              libftdi
+
+              # For clang-tidy and clang-format.
+              clang_for_formatting
+              clang_for_tidy
+
+              # For buildifier, buildozer.
+              bazel-buildtools
+              bant
+
+              # Profiling and sanitizers.
+              linuxPackages_latest.perf
+              pprof
+              perf_data_converter
+              valgrind
+
+              # FPGA utils.
+              openfpgaloader
+            ];
+
+            CLANG_TIDY = "${clang_for_tidy}/bin/clang-tidy";
+            CLANG_FORMAT = "${clang_for_formatting}/bin/clang-format";
+
+            shellHook = ''
+              exec bash
+            '';
+          };
+
+        # Package fpga-assembler.
+        packages.default =
+          (pkgs.callPackage (
+            {
+              buildBazelPackage,
+              stdenv,
+              fetchFromGitHub,
+              lib,
+              nix-gitignore,
+            }:
+            let
+              system = stdenv.hostPlatform.system;
+              registry = fetchFromGitHub {
+                owner = "bazelbuild";
+                repo = "bazel-central-registry";
+                rev = "63f3af762b2fdd7acaa7987856cd3ac314eaea09";
+                hash = "sha256-ugNzoP0gdrhl9vH1TRdwoevuTsSqjitXnAoMSSTlCgI=";
+              };
+            in
+            buildBazelPackage {
+              pname = "fpga-as";
+
+              version = "0.0.1";
+
+              src = nix-gitignore.gitignoreSourcePure [ ] ./.;
+
+              bazelFlags = [
+                "--registry"
+                "file://${registry}"
+              ];
+
+              postPatch = ''
+                patchShebangs scripts/create-workspace-status.sh
+              '';
+
+              fetchAttrs = {
+                hash =
+                  {
+                    aarch64-linux = "sha256-E4VHjDa0qkHmKUNpTBfJi7dhMLcd1z5he+p31/XvUl8=";
+                    x86_64-linux = "sha256-hVBJB0Hsd9sXuEoNcjhTkbPl89vlZT1w39JppCD+n8Y=";
+                  }
+                  .${system} or (throw "No hash for system: ${system}");
+              };
+
+              removeRulesCC = false;
+              removeLocalConfigCc = false;
+              removeLocalConfigSh = false;
+
+              nativeBuildInputs = [
+                common.jdk
+                pkgs.git
+                pkgs.bash
+                # Convenient tool to enter into the sandbox and start debugging.
+                pkgs.breakpointHook
+              ];
+
+              bazel = common.bazel;
+
+              bazelBuildFlags = [ "-c opt" ];
+              bazelTestTargets = [ "//..." ];
+              bazelTargets = [ "//fpga:fpga-as" ];
+
+              buildAttrs = {
+                installPhase = ''
+                  install -D --strip bazel-bin/fpga/fpga-as "$out/bin/fpga-as"
+                '';
+              };
+
+              meta = {
+                description = "Tool to convert FASM to FPGA bitstream.";
+                homepage = "https://github.com/lromor/fpga-assembler";
+                license = lib.licenses.asl20;
+                platforms = lib.platforms.linux;
+              };
+            }
+          ) { }).overrideAttrs
+            (
+              final: prev: {
+                # Fixup the deps so they always contain correrct
+                # shebangs paths pointing to the store.
+                deps = prev.deps.overrideAttrs (
+                  final: prev: {
+                    installPhase =
+                      ''
+                        patchShebangs $bazelOut/external
+                      ''
+                      + prev.installPhase;
+                  }
+                );
+              }
+            );
+      }
+    );
+}