Merge pull request #709 from daveshah1/oxide-build

Add Yosys/nextpnr-nexus/oxide flow for CrossLink-NX

litex/build/lattice/oxide.py

@@ -0,0 +1,218 @@
+#
+# This file is part of LiteX.
+#
+# Copyright (c) 2018-2019 Florent Kermarrec <florent@enjoy-digital.fr>
+# Copyright (c) 2019-2020 David Shah <dave@ds0.me>
+# Copyright (c) 2018 William D. Jones <thor0505@comcast.net>
+# SPDX-License-Identifier: BSD-2-Clause
+
+import os
+import subprocess
+import sys
+from shutil import which
+
+from migen.fhdl.structure import _Fragment
+
+from litex.build.generic_platform import *
+from litex.build import tools
+from litex.build.lattice import common
+from litex.build.lattice.radiant import _format_constraint, _format_ldc, _build_pdc
+
+import math
+
+# Yosys/Nextpnr Helpers/Templates ------------------------------------------------------------------
+
+_yosys_template = [
+    "verilog_defaults -push",
+    "verilog_defaults -add -defer",
+    "{read_files}",
+    "verilog_defaults -pop",
+    "attrmap -tocase keep -imap keep=\"true\" keep=1 -imap keep=\"false\" keep=0 -remove keep=0",
+    "synth_nexus -flatten {nwl} {abc} -json {build_name}.json -top {build_name}",
+]
+
+def _yosys_import_sources(platform):
+    includes = ""
+    reads = []
+    for path in platform.verilog_include_paths:
+        includes += " -I" + path
+    for filename, language, library in platform.sources:
+        reads.append("read_{}{} {}".format(
+            language, includes, filename))
+    return "\n".join(reads)
+
+def _build_yosys(template, platform, nowidelut, abc9, build_name):
+    ys = []
+    for l in template:
+        ys.append(l.format(
+            build_name = build_name,
+            nwl        = "-nowidelut" if nowidelut else "",
+            abc        = "-abc9" if abc9 else "",
+            read_files = _yosys_import_sources(platform)
+        ))
+    tools.write_to_file(build_name + ".ys", "\n".join(ys))
+
+# Script -------------------------------------------------------------------------------------------
+
+_build_template = [
+    "yosys -l {build_name}.rpt {build_name}.ys",
+    "nextpnr-nexus --json {build_name}.json --pdc {build_name}.pdc --fasm {build_name}.fasm \
+    --device {device} {timefailarg} {ignoreloops} --seed {seed}",
+    "prjoxide pack {build_name}.fasm {build_name}.bit"
+]
+
+def _build_script(source, build_template, build_name, device, timingstrict, ignoreloops, seed):
+    if sys.platform in ("win32", "cygwin"):
+        script_ext = ".bat"
+        script_contents = "@echo off\nrem Autogenerated by LiteX / git: " + tools.get_litex_git_revision() + "\n\n"
+        fail_stmt = " || exit /b"
+    else:
+        script_ext = ".sh"
+        script_contents = "# Autogenerated by LiteX / git: " + tools.get_litex_git_revision() + "\nset -e\n"
+        fail_stmt = ""
+
+    for s in build_template:
+        s_fail = s + "{fail_stmt}\n"  # Required so Windows scripts fail early.
+        script_contents += s_fail.format(
+            build_name      = build_name,
+            device          = device,
+            timefailarg     = "--timing-allow-fail" if not timingstrict else "",
+            ignoreloops     = "--ignore-loops" if ignoreloops else "",
+            fail_stmt       = fail_stmt,
+            seed            = seed,
+        )
+    script_file = "build_" + build_name + script_ext
+    tools.write_to_file(script_file, script_contents, force_unix=False)
+
+    return script_file
+
+def _run_script(script):
+    if sys.platform in ("win32", "cygwin"):
+        shell = ["cmd", "/c"]
+    else:
+        shell = ["bash"]
+
+    if which("yosys") is None or which("nextpnr-nexus") is None:
+        msg = "Unable to find Yosys/Nextpnr toolchain, please:\n"
+        msg += "- Add Yosys/Nextpnr toolchain to your $PATH."
+        raise OSError(msg)
+
+    if subprocess.call(shell + [script]) != 0:
+        raise OSError("Error occured during Yosys/Nextpnr's script execution.")
+
+# LatticeOxideToolchain --------------------------------------------------------------------------
+
+class LatticeOxideToolchain:
+    attr_translate = {
+        # FIXME: document
+        "keep": ("keep", "true"),
+        "no_retiming":      None,
+        "async_reg":        None,
+        "mr_ff":            None,
+        "mr_false_path":    None,
+        "ars_ff1":          None,
+        "ars_ff2":          None,
+        "ars_false_path":   None,
+        "no_shreg_extract": None
+    }
+
+    special_overrides = common.lattice_NX_special_overrides
+
+    def __init__(self):
+        self.yosys_template   = _yosys_template
+        self.build_template   = _build_template
+        self.clocks      = {}
+        self.false_paths = set() # FIXME: use it
+
+    def build(self, platform, fragment,
+        build_dir      = "build",
+        build_name     = "top",
+        run            = True,
+        nowidelut      = False,
+        abc9           = False,
+        timingstrict   = False,
+        ignoreloops    = False,
+        seed           = 1,
+        es_device      = False,
+        **kwargs):
+
+        # Create build directory
+        os.makedirs(build_dir, exist_ok=True)
+        cwd = os.getcwd()
+        os.chdir(build_dir)
+
+        # Finalize design
+        if not isinstance(fragment, _Fragment):
+            fragment = fragment.get_fragment()
+        platform.finalize(fragment)
+
+        # Generate verilog
+        v_output = platform.get_verilog(fragment, name=build_name, **kwargs)
+        named_sc, named_pc = platform.resolve_signals(v_output.ns)
+        top_file = build_name + ".v"
+        v_output.write(top_file)
+        platform.add_source(top_file)
+
+        # Generate design constraints file (.pdc)
+        _build_pdc(named_sc, named_pc, self.clocks, v_output.ns, build_name)
+
+        # Generate Yosys script
+        _build_yosys(self.yosys_template, platform, nowidelut, abc9, build_name)
+
+        # N.B. Radiant does not allow a choice between ES1/production, this is determined
+        # solely by the installed Radiant version. nextpnr/oxide supports both, so we
+        # must choose what we are dealing with
+        device = platform.device
+        if es_device:
+            device += "ES"
+
+        # Generate build script
+        script = _build_script(False, self.build_template, build_name, device,
+                               timingstrict, ignoreloops, seed)
+        # Run
+        if run:
+            _run_script(script)
+
+        os.chdir(cwd)
+
+        return v_output.ns
+
+    # N.B. these are currently ignored, but will be supported very soon
+    def add_period_constraint(self, platform, clk, period):
+        clk.attr.add("keep")
+        period = math.floor(period*1e3)/1e3 # round to lowest picosecond
+        if clk in self.clocks:
+            if period != self.clocks[clk]:
+                raise ValueError("Clock already constrained to {:.2f}ns, new constraint to {:.2f}ns"
+                    .format(self.clocks[clk], period))
+        self.clocks[clk] = period
+
+    def add_false_path_constraint(self, platform, from_, to):
+        from_.attr.add("keep")
+        to.attr.add("keep")
+        if (to, from_) not in self.false_paths:
+            self.false_paths.add((from_, to))
+
+def oxide_args(parser):
+    parser.add_argument("--yosys-nowidelut", action="store_true",
+                        help="pass '-nowidelut' to yosys synth_nexus")
+    parser.add_argument("--yosys-abc9", action="store_true",
+                        help="pass '-abc9' to yosys synth_nexus")
+    parser.add_argument("--nextpnr-timingstrict", action="store_true",
+                        help="fail if timing not met, i.e., do NOT pass '--timing-allow-fail' to nextpnr")
+    parser.add_argument("--nextpnr-ignoreloops", action="store_true",
+                        help="ignore combinational loops in timing analysis, i.e. pass '--ignore-loops' to nextpnr")
+    parser.add_argument("--nextpnr-seed", default=1, type=int,
+                        help="seed to pass to nextpnr")
+    parser.add_argument("--nexus-es-device", action="store_true",
+                        help="device is a ES1 Nexus part")
+
+def oxide_argdict(args):
+    return {
+        "nowidelut":    args.yosys_nowidelut,
+        "abc9":         args.yosys_abc9,
+        "timingstrict": args.nextpnr_timingstrict,
+        "ignoreloops":  args.nextpnr_ignoreloops,
+        "seed":         args.nextpnr_seed,
+        "es_device":    args.nexus_es_device,
+    }

litex/build/lattice/platform.py

@@ -6,7 +6,7 @@
 # SPDX-License-Identifier: BSD-2-Clause
 
 from litex.build.generic_platform import GenericPlatform
-from litex.build.lattice import common, diamond, icestorm, trellis, radiant
+from litex.build.lattice import common, diamond, icestorm, trellis, radiant, oxide
 
 # LatticePlatform ----------------------------------------------------------------------------------
 
@@ -24,6 +24,8 @@ class LatticePlatform(GenericPlatform):
             self.toolchain = icestorm.LatticeIceStormToolchain()
         elif toolchain == "radiant":
             self.toolchain = radiant.LatticeRadiantToolchain()
+        elif toolchain == "oxide":
+            self.toolchain = oxide.LatticeOxideToolchain()
         else:
             raise ValueError("Unknown toolchain")