diff --git a/CMakeLists.txt b/CMakeLists.txt
index d9c18554..b24e6255 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -66,7 +66,7 @@ endif()
 set(PROGRAM_PREFIX "" CACHE STRING "Name prefix for executables")
 
 # List of families to build
-set(FAMILIES generic ice40 ecp5)
+set(FAMILIES generic ice40 ecp5 gowin)
 
 set(ARCH "" CACHE STRING "Architecture family for nextpnr build")
 set_property(CACHE ARCH PROPERTY STRINGS ${FAMILIES})
@@ -99,9 +99,9 @@ if (MSVC)
 else()
     set(CMAKE_CXX_FLAGS_DEBUG "-Wall -fPIC -ggdb -pipe")
     if (USE_OPENMP)
-        set(CMAKE_CXX_FLAGS_RELEASE "-Wall -fPIC -O3 -g -pipe -fopenmp")
+        set(CMAKE_CXX_FLAGS_RELEASE "-Wall -fPIC -O0 -g -pipe -fopenmp")
     else()
-        set(CMAKE_CXX_FLAGS_RELEASE "-Wall -fPIC -O3 -g -pipe")
+        set(CMAKE_CXX_FLAGS_RELEASE "-Wall -fPIC -O0 -g -pipe")
     endif()
 endif()
 
diff --git a/common/timing_opt.cc b/common/timing_opt.cc
index 309eedf2..eae15fb2 100644
--- a/common/timing_opt.cc
+++ b/common/timing_opt.cc
@@ -59,7 +59,7 @@ template <> struct hash<std::pair<int, NEXTPNR_NAMESPACE_PREFIX BelId>>
         return seed;
     }
 };
-#ifndef ARCH_GENERIC
+#if !defined(ARCH_GENERIC) && !defined(ARCH_GOWIN)
 template <> struct hash<std::pair<NEXTPNR_NAMESPACE_PREFIX IdString, NEXTPNR_NAMESPACE_PREFIX BelId>>
 {
     std::size_t
diff --git a/gowin/CMakeLists.txt b/gowin/CMakeLists.txt
new file mode 100644
index 00000000..80293c4c
--- /dev/null
+++ b/gowin/CMakeLists.txt
@@ -0,0 +1,54 @@
+cmake_minimum_required(VERSION 3.5)
+project(chipdb-gowin NONE)
+
+set(ALL_GOWIN_DEVICES GW1N-1 GW1N-9)
+set(GOWIN_DEVICES ${ALL_GOWIN_DEVICES} CACHE STRING
+    "Include support for these Gowin devices (available: ${ALL_GOWIN_DEVICES})")
+message(STATUS "Enabled Gowin devices: ${GOWIN_DEVICES}")
+
+find_program (GOWIN_BBA_EXECUTABLE gowin_bba)
+message(STATUS "gowin_bba executable: ${GOWIN_BBA_EXECUTABLE}")
+
+if(DEFINED GOWIN_CHIPDB)
+    add_custom_target(chipdb-gowin-bbas ALL)
+else()
+    find_package(PythonInterp 3.6 REQUIRED)
+
+    # shared among all families
+    set(SERIALIZE_CHIPDBS TRUE CACHE BOOL
+        "Serialize device data preprocessing to minimize memory use")
+
+    set(all_device_bbas)
+    file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/chipdb)
+    foreach(device ${GOWIN_DEVICES})
+        if(NOT device IN_LIST ALL_GOWIN_DEVICES)
+            message(FATAL_ERROR "Device ${device} is not a supported Gowin device")
+        endif()
+
+        set(device_bba chipdb/chipdb-${device}.bba)
+        add_custom_command(
+            OUTPUT ${device_bba}
+            COMMAND ${GOWIN_BBA_EXECUTABLE} -d ${device} -o ${device_bba}.new
+            # atomically update
+            COMMAND ${CMAKE_COMMAND} -E rename ${device_bba}.new ${device_bba}
+            DEPENDS
+                ${GOWIN_BBA_EXECUTABLE}
+                ${PREVIOUS_CHIPDB_TARGET}
+            VERBATIM)
+        list(APPEND all_device_bbas ${device_bba})
+        if(SERIALIZE_CHIPDBS)
+            set(PREVIOUS_CHIPDB_TARGET ${CMAKE_CURRENT_BINARY_DIR}/${device_bba})
+        endif()
+    endforeach()
+
+    add_custom_target(chipdb-gowin-bbas ALL DEPENDS ${all_device_bbas})
+
+    get_directory_property(has_parent PARENT_DIRECTORY)
+    if(has_parent)
+        set(GOWIN_CHIPDB ${CMAKE_CURRENT_BINARY_DIR}/chipdb PARENT_SCOPE)
+        # serialize chipdb build across multiple architectures
+        set(PREVIOUS_CHIPDB_TARGET chipdb-gowin-bbas PARENT_SCOPE)
+    else()
+        message(STATUS "Build nextpnr with -DGOWIN_CHIPDB=${CMAKE_CURRENT_BINARY_DIR}/chipdb")
+    endif()
+endif()
diff --git a/gowin/arch.cc b/gowin/arch.cc
new file mode 100644
index 00000000..588fdae4
--- /dev/null
+++ b/gowin/arch.cc
@@ -0,0 +1,810 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2018  Clifford Wolf <clifford@symbioticeda.com>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include <iostream>
+#include <math.h>
+#include "nextpnr.h"
+#include "embed.h"
+#include "placer1.h"
+#include "placer_heap.h"
+#include "router1.h"
+#include "router2.h"
+#include "util.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+
+WireInfo &Arch::wire_info(IdString wire)
+{
+    auto w = wires.find(wire);
+    if (w == wires.end())
+        NPNR_ASSERT_FALSE_STR("no wire named " + wire.str(this));
+    return w->second;
+}
+
+PipInfo &Arch::pip_info(IdString pip)
+{
+    auto p = pips.find(pip);
+    if (p == pips.end())
+        NPNR_ASSERT_FALSE_STR("no pip named " + pip.str(this));
+    return p->second;
+}
+
+BelInfo &Arch::bel_info(IdString bel)
+{
+    auto b = bels.find(bel);
+    if (b == bels.end())
+        NPNR_ASSERT_FALSE_STR("no bel named " + bel.str(this));
+    return b->second;
+}
+
+void Arch::addWire(IdString name, IdString type, int x, int y)
+{
+    NPNR_ASSERT(wires.count(name) == 0);
+    WireInfo &wi = wires[name];
+    wi.name = name;
+    wi.type = type;
+    wi.x = x;
+    wi.y = y;
+
+    wire_ids.push_back(name);
+}
+
+void Arch::addPip(IdString name, IdString type, IdString srcWire, IdString dstWire, DelayInfo delay, Loc loc)
+{
+    NPNR_ASSERT(pips.count(name) == 0);
+    PipInfo &pi = pips[name];
+    pi.name = name;
+    pi.type = type;
+    pi.srcWire = srcWire;
+    pi.dstWire = dstWire;
+    pi.delay = delay;
+    pi.loc = loc;
+
+    wire_info(srcWire).downhill.push_back(name);
+    wire_info(dstWire).uphill.push_back(name);
+    pip_ids.push_back(name);
+
+    if (int(tilePipDimZ.size()) <= loc.x)
+        tilePipDimZ.resize(loc.x + 1);
+
+    if (int(tilePipDimZ[loc.x].size()) <= loc.y)
+        tilePipDimZ[loc.x].resize(loc.y + 1);
+
+    gridDimX = std::max(gridDimX, loc.x + 1);
+    gridDimY = std::max(gridDimY, loc.x + 1);
+    tilePipDimZ[loc.x][loc.y] = std::max(tilePipDimZ[loc.x][loc.y], loc.z + 1);
+}
+
+void Arch::addBel(IdString name, IdString type, Loc loc, bool gb)
+{
+    NPNR_ASSERT(bels.count(name) == 0);
+    NPNR_ASSERT(bel_by_loc.count(loc) == 0);
+    BelInfo &bi = bels[name];
+    bi.name = name;
+    bi.type = type;
+    bi.x = loc.x;
+    bi.y = loc.y;
+    bi.z = loc.z;
+    bi.gb = gb;
+
+    bel_ids.push_back(name);
+    bel_by_loc[loc] = name;
+
+    if (int(bels_by_tile.size()) <= loc.x)
+        bels_by_tile.resize(loc.x + 1);
+
+    if (int(bels_by_tile[loc.x].size()) <= loc.y)
+        bels_by_tile[loc.x].resize(loc.y + 1);
+
+    bels_by_tile[loc.x][loc.y].push_back(name);
+
+    if (int(tileBelDimZ.size()) <= loc.x)
+        tileBelDimZ.resize(loc.x + 1);
+
+    if (int(tileBelDimZ[loc.x].size()) <= loc.y)
+        tileBelDimZ[loc.x].resize(loc.y + 1);
+
+    gridDimX = std::max(gridDimX, loc.x + 1);
+    gridDimY = std::max(gridDimY, loc.x + 1);
+    tileBelDimZ[loc.x][loc.y] = std::max(tileBelDimZ[loc.x][loc.y], loc.z + 1);
+}
+
+void Arch::addBelInput(IdString bel, IdString name, IdString wire)
+{
+    NPNR_ASSERT(bel_info(bel).pins.count(name) == 0);
+    PinInfo &pi = bel_info(bel).pins[name];
+    pi.name = name;
+    pi.wire = wire;
+    pi.type = PORT_IN;
+
+    wire_info(wire).downhill_bel_pins.push_back(BelPin{bel, name});
+    wire_info(wire).bel_pins.push_back(BelPin{bel, name});
+}
+
+void Arch::addBelOutput(IdString bel, IdString name, IdString wire)
+{
+    NPNR_ASSERT(bel_info(bel).pins.count(name) == 0);
+    PinInfo &pi = bel_info(bel).pins[name];
+    pi.name = name;
+    pi.wire = wire;
+    pi.type = PORT_OUT;
+
+    wire_info(wire).uphill_bel_pin = BelPin{bel, name};
+    wire_info(wire).bel_pins.push_back(BelPin{bel, name});
+}
+
+void Arch::addBelInout(IdString bel, IdString name, IdString wire)
+{
+    NPNR_ASSERT(bel_info(bel).pins.count(name) == 0);
+    PinInfo &pi = bel_info(bel).pins[name];
+    pi.name = name;
+    pi.wire = wire;
+    pi.type = PORT_INOUT;
+
+    wire_info(wire).downhill_bel_pins.push_back(BelPin{bel, name});
+    wire_info(wire).bel_pins.push_back(BelPin{bel, name});
+}
+
+void Arch::addGroupBel(IdString group, IdString bel) { groups[group].bels.push_back(bel); }
+
+void Arch::addGroupWire(IdString group, IdString wire) { groups[group].wires.push_back(wire); }
+
+void Arch::addGroupPip(IdString group, IdString pip) { groups[group].pips.push_back(pip); }
+
+void Arch::addGroupGroup(IdString group, IdString grp) { groups[group].groups.push_back(grp); }
+
+void Arch::addDecalGraphic(DecalId decal, const GraphicElement &graphic)
+{
+    decal_graphics[decal].push_back(graphic);
+    refreshUi();
+}
+
+void Arch::setWireDecal(WireId wire, DecalXY decalxy)
+{
+    wire_info(wire).decalxy = decalxy;
+    refreshUiWire(wire);
+}
+
+void Arch::setPipDecal(PipId pip, DecalXY decalxy)
+{
+    pip_info(pip).decalxy = decalxy;
+    refreshUiPip(pip);
+}
+
+void Arch::setBelDecal(BelId bel, DecalXY decalxy)
+{
+    bel_info(bel).decalxy = decalxy;
+    refreshUiBel(bel);
+}
+
+void Arch::setGroupDecal(GroupId group, DecalXY decalxy)
+{
+    groups[group].decalxy = decalxy;
+    refreshUiGroup(group);
+}
+
+void Arch::setWireAttr(IdString wire, IdString key, const std::string &value) { wire_info(wire).attrs[key] = value; }
+
+void Arch::setPipAttr(IdString pip, IdString key, const std::string &value) { pip_info(pip).attrs[key] = value; }
+
+void Arch::setBelAttr(IdString bel, IdString key, const std::string &value) { bel_info(bel).attrs[key] = value; }
+
+void Arch::setLutK(int K) { args.K = K; }
+
+void Arch::setDelayScaling(double scale, double offset)
+{
+    args.delayScale = scale;
+    args.delayOffset = offset;
+}
+
+void Arch::addCellTimingClock(IdString cell, IdString port) { cellTiming[cell].portClasses[port] = TMG_CLOCK_INPUT; }
+
+void Arch::addCellTimingDelay(IdString cell, IdString fromPort, IdString toPort, DelayInfo delay)
+{
+    if (get_or_default(cellTiming[cell].portClasses, fromPort, TMG_IGNORE) == TMG_IGNORE)
+        cellTiming[cell].portClasses[fromPort] = TMG_COMB_INPUT;
+    if (get_or_default(cellTiming[cell].portClasses, toPort, TMG_IGNORE) == TMG_IGNORE)
+        cellTiming[cell].portClasses[toPort] = TMG_COMB_OUTPUT;
+    cellTiming[cell].combDelays[CellDelayKey{fromPort, toPort}] = delay;
+}
+
+void Arch::addCellTimingSetupHold(IdString cell, IdString port, IdString clock, DelayInfo setup, DelayInfo hold)
+{
+    TimingClockingInfo ci;
+    ci.clock_port = clock;
+    ci.edge = RISING_EDGE;
+    ci.setup = setup;
+    ci.hold = hold;
+    cellTiming[cell].clockingInfo[port].push_back(ci);
+    cellTiming[cell].portClasses[port] = TMG_REGISTER_INPUT;
+}
+
+void Arch::addCellTimingClockToOut(IdString cell, IdString port, IdString clock, DelayInfo clktoq)
+{
+    TimingClockingInfo ci;
+    ci.clock_port = clock;
+    ci.edge = RISING_EDGE;
+    ci.clockToQ = clktoq;
+    cellTiming[cell].clockingInfo[port].push_back(ci);
+    cellTiming[cell].portClasses[port] = TMG_REGISTER_OUTPUT;
+}
+
+// ---------------------------------------------------------------
+
+//TODO represent wires more intelligently.
+IdString Arch::wireToGlobal(int row, int col, const DatabasePOD* db, IdString wire) {
+    std::string wirename = wire.str(this);
+    char buf[32];
+    if( wirename == "VCC" || wirename == "GND" ) {
+        return wire;
+    }
+    if(!isdigit(wirename[1]) || !isdigit(wirename[2]) || !isdigit(wirename[3])) {
+        snprintf(buf, 32, "R%dC%d_%s", row+1, col+1, wirename.c_str());
+        return id(buf);
+    }
+    char direction = wirename[0];
+    int num = std::stoi(wirename.substr(1, 2));
+    int segment = std::stoi(wirename.substr(3, 1));
+    int rootrow, rootcol;
+    switch (direction)
+    {
+    case 'N':
+        rootrow = row + segment;
+        rootcol = col;
+        break;
+    case 'S':
+        rootrow = row - segment;
+        rootcol = col;
+        break;
+    case 'E':
+        rootrow = row;
+        rootcol = col - segment;
+        break;
+    case 'W':
+        rootrow = row;
+        rootcol = col + segment;
+        break;
+    default:
+        snprintf(buf, 32, "R%dC%d_%s", row+1, col+1, wirename.c_str());
+        return id(buf);
+        break;
+    }
+    // wires wrap around the edges
+    // assumes 0-based indexes
+    if(rootrow < 0) {
+        rootrow = -1-rootrow;
+        direction = 'N';
+    } else if(rootcol < 0) {
+        rootcol = -1-rootcol;
+        direction = 'W';
+    } else if(rootrow >= db->rows) {
+        rootrow = 2*db->rows-1-rootrow;
+        direction = 'S';
+    } else if(rootcol >= db->cols) {
+        rootcol = 2*db->cols-1-rootcol;
+        direction = 'E';
+    }
+    snprintf(buf, 32, "R%dC%d_%c%d", rootrow+1, rootcol+1, direction, num);
+    return id(buf);
+}
+
+Arch::Arch(ArchArgs args) : args(args)
+{
+    family = "GW1N-9";
+    device = "GW1NR-9";
+    speed = "C6/E5"; // or whatever
+    package = "QFN48"; // or something
+
+    // Load database
+    std::string chipdb = stringf("gowin/chipdb-%s.bin", family.c_str());
+    auto db = reinterpret_cast<const DatabasePOD*>(get_chipdb(chipdb));
+    if (db == nullptr)
+        log_error("Failed to load chipdb '%s'\n", chipdb.c_str());
+    if (db->family.get() != family) {
+        log_error("Database is for family '%s' but provided device is family '%s'.\n", db->family.get(),
+                  family.c_str());
+    }
+    // setup id strings
+    for (size_t i = 0; i < db->num_ids; i++) {
+        IdString::initialize_add(this, db->id_strs[i].get(), uint32_t(i)+db->num_constids);
+    }
+    // setup db
+    for (int i=0; i < db->rows*db->cols; i++) {
+        int row = i/db->cols;
+        int col = i%db->cols;
+        const TilePOD* tile = db->grid[i].get();
+        for(unsigned int j=0; j < tile->num_pips; j++) {
+            const PairPOD pip = tile->pips[j];
+            IdString gdestname = wireToGlobal(row, col, db, pip.dest_id);
+            if(wires.count(gdestname) == 0) addWire(gdestname, pip.dest_id, col, row);
+            IdString gsrcname = wireToGlobal(row, col, db, pip.src_id);
+            if(wires.count(gsrcname) == 0) addWire(gsrcname, pip.src_id, col, row);
+        }
+        for(unsigned int j=0; j < tile->num_clock_pips; j++) {
+            const PairPOD pip = tile->clock_pips[j];
+            IdString gdestname = wireToGlobal(row, col, db, pip.dest_id);
+            if(wires.count(gdestname) == 0) addWire(gdestname, pip.dest_id, col, row);
+            IdString gsrcname = wireToGlobal(row, col, db, pip.src_id);
+            if(wires.count(gsrcname) == 0) addWire(gsrcname, pip.src_id, col, row);
+        }
+    }
+    // Dummy for empty decals
+    decal_graphics[IdString()];
+}
+
+void IdString::initialize_arch(const BaseCtx *ctx) {}
+
+// ---------------------------------------------------------------
+
+BelId Arch::getBelByName(IdString name) const
+{
+    if (bels.count(name))
+        return name;
+    return BelId();
+}
+
+IdString Arch::getBelName(BelId bel) const { return bel; }
+
+Loc Arch::getBelLocation(BelId bel) const
+{
+    auto &info = bels.at(bel);
+    return Loc(info.x, info.y, info.z);
+}
+
+BelId Arch::getBelByLocation(Loc loc) const
+{
+    auto it = bel_by_loc.find(loc);
+    if (it != bel_by_loc.end())
+        return it->second;
+    return BelId();
+}
+
+const std::vector<BelId> &Arch::getBelsByTile(int x, int y) const { return bels_by_tile.at(x).at(y); }
+
+bool Arch::getBelGlobalBuf(BelId bel) const { return bels.at(bel).gb; }
+
+uint32_t Arch::getBelChecksum(BelId bel) const
+{
+    // FIXME
+    return 0;
+}
+
+void Arch::bindBel(BelId bel, CellInfo *cell, PlaceStrength strength)
+{
+    bels.at(bel).bound_cell = cell;
+    cell->bel = bel;
+    cell->belStrength = strength;
+    refreshUiBel(bel);
+}
+
+void Arch::unbindBel(BelId bel)
+{
+    bels.at(bel).bound_cell->bel = BelId();
+    bels.at(bel).bound_cell->belStrength = STRENGTH_NONE;
+    bels.at(bel).bound_cell = nullptr;
+    refreshUiBel(bel);
+}
+
+bool Arch::checkBelAvail(BelId bel) const { return bels.at(bel).bound_cell == nullptr; }
+
+CellInfo *Arch::getBoundBelCell(BelId bel) const { return bels.at(bel).bound_cell; }
+
+CellInfo *Arch::getConflictingBelCell(BelId bel) const { return bels.at(bel).bound_cell; }
+
+const std::vector<BelId> &Arch::getBels() const { return bel_ids; }
+
+IdString Arch::getBelType(BelId bel) const { return bels.at(bel).type; }
+
+const std::map<IdString, std::string> &Arch::getBelAttrs(BelId bel) const { return bels.at(bel).attrs; }
+
+WireId Arch::getBelPinWire(BelId bel, IdString pin) const
+{
+    const auto &bdata = bels.at(bel);
+    if (!bdata.pins.count(pin))
+        log_error("bel '%s' has no pin '%s'\n", bel.c_str(this), pin.c_str(this));
+    return bdata.pins.at(pin).wire;
+}
+
+PortType Arch::getBelPinType(BelId bel, IdString pin) const { return bels.at(bel).pins.at(pin).type; }
+
+std::vector<IdString> Arch::getBelPins(BelId bel) const
+{
+    std::vector<IdString> ret;
+    for (auto &it : bels.at(bel).pins)
+        ret.push_back(it.first);
+    return ret;
+}
+
+// ---------------------------------------------------------------
+
+WireId Arch::getWireByName(IdString name) const
+{
+    if (wires.count(name))
+        return name;
+    return WireId();
+}
+
+IdString Arch::getWireName(WireId wire) const { return wire; }
+
+IdString Arch::getWireType(WireId wire) const { return wires.at(wire).type; }
+
+const std::map<IdString, std::string> &Arch::getWireAttrs(WireId wire) const { return wires.at(wire).attrs; }
+
+uint32_t Arch::getWireChecksum(WireId wire) const
+{
+    // FIXME
+    return 0;
+}
+
+void Arch::bindWire(WireId wire, NetInfo *net, PlaceStrength strength)
+{
+    wires.at(wire).bound_net = net;
+    net->wires[wire].pip = PipId();
+    net->wires[wire].strength = strength;
+    refreshUiWire(wire);
+}
+
+void Arch::unbindWire(WireId wire)
+{
+    auto &net_wires = wires.at(wire).bound_net->wires;
+
+    auto pip = net_wires.at(wire).pip;
+    if (pip != PipId()) {
+        pips.at(pip).bound_net = nullptr;
+        refreshUiPip(pip);
+    }
+
+    net_wires.erase(wire);
+    wires.at(wire).bound_net = nullptr;
+    refreshUiWire(wire);
+}
+
+bool Arch::checkWireAvail(WireId wire) const { return wires.at(wire).bound_net == nullptr; }
+
+NetInfo *Arch::getBoundWireNet(WireId wire) const { return wires.at(wire).bound_net; }
+
+NetInfo *Arch::getConflictingWireNet(WireId wire) const { return wires.at(wire).bound_net; }
+
+const std::vector<BelPin> &Arch::getWireBelPins(WireId wire) const { return wires.at(wire).bel_pins; }
+
+const std::vector<WireId> &Arch::getWires() const { return wire_ids; }
+
+// ---------------------------------------------------------------
+
+PipId Arch::getPipByName(IdString name) const
+{
+    if (pips.count(name))
+        return name;
+    return PipId();
+}
+
+IdString Arch::getPipName(PipId pip) const { return pip; }
+
+IdString Arch::getPipType(PipId pip) const { return pips.at(pip).type; }
+
+const std::map<IdString, std::string> &Arch::getPipAttrs(PipId pip) const { return pips.at(pip).attrs; }
+
+uint32_t Arch::getPipChecksum(PipId wire) const
+{
+    // FIXME
+    return 0;
+}
+
+void Arch::bindPip(PipId pip, NetInfo *net, PlaceStrength strength)
+{
+    WireId wire = pips.at(pip).dstWire;
+    pips.at(pip).bound_net = net;
+    wires.at(wire).bound_net = net;
+    net->wires[wire].pip = pip;
+    net->wires[wire].strength = strength;
+    refreshUiPip(pip);
+    refreshUiWire(wire);
+}
+
+void Arch::unbindPip(PipId pip)
+{
+    WireId wire = pips.at(pip).dstWire;
+    wires.at(wire).bound_net->wires.erase(wire);
+    pips.at(pip).bound_net = nullptr;
+    wires.at(wire).bound_net = nullptr;
+    refreshUiPip(pip);
+    refreshUiWire(wire);
+}
+
+bool Arch::checkPipAvail(PipId pip) const { return pips.at(pip).bound_net == nullptr; }
+
+NetInfo *Arch::getBoundPipNet(PipId pip) const { return pips.at(pip).bound_net; }
+
+NetInfo *Arch::getConflictingPipNet(PipId pip) const { return pips.at(pip).bound_net; }
+
+WireId Arch::getConflictingPipWire(PipId pip) const { return pips.at(pip).bound_net ? pips.at(pip).dstWire : WireId(); }
+
+const std::vector<PipId> &Arch::getPips() const { return pip_ids; }
+
+Loc Arch::getPipLocation(PipId pip) const { return pips.at(pip).loc; }
+
+WireId Arch::getPipSrcWire(PipId pip) const { return pips.at(pip).srcWire; }
+
+WireId Arch::getPipDstWire(PipId pip) const { return pips.at(pip).dstWire; }
+
+DelayInfo Arch::getPipDelay(PipId pip) const { return pips.at(pip).delay; }
+
+const std::vector<PipId> &Arch::getPipsDownhill(WireId wire) const { return wires.at(wire).downhill; }
+
+const std::vector<PipId> &Arch::getPipsUphill(WireId wire) const { return wires.at(wire).uphill; }
+
+// ---------------------------------------------------------------
+
+GroupId Arch::getGroupByName(IdString name) const { return name; }
+
+IdString Arch::getGroupName(GroupId group) const { return group; }
+
+std::vector<GroupId> Arch::getGroups() const
+{
+    std::vector<GroupId> ret;
+    for (auto &it : groups)
+        ret.push_back(it.first);
+    return ret;
+}
+
+const std::vector<BelId> &Arch::getGroupBels(GroupId group) const { return groups.at(group).bels; }
+
+const std::vector<WireId> &Arch::getGroupWires(GroupId group) const { return groups.at(group).wires; }
+
+const std::vector<PipId> &Arch::getGroupPips(GroupId group) const { return groups.at(group).pips; }
+
+const std::vector<GroupId> &Arch::getGroupGroups(GroupId group) const { return groups.at(group).groups; }
+
+// ---------------------------------------------------------------
+
+delay_t Arch::estimateDelay(WireId src, WireId dst) const
+{
+    const WireInfo &s = wires.at(src);
+    const WireInfo &d = wires.at(dst);
+    int dx = abs(s.x - d.x);
+    int dy = abs(s.y - d.y);
+    return (dx + dy) * args.delayScale + args.delayOffset;
+}
+
+delay_t Arch::predictDelay(const NetInfo *net_info, const PortRef &sink) const
+{
+    const auto &driver = net_info->driver;
+    auto driver_loc = getBelLocation(driver.cell->bel);
+    auto sink_loc = getBelLocation(sink.cell->bel);
+
+    int dx = abs(sink_loc.x - driver_loc.x);
+    int dy = abs(sink_loc.y - driver_loc.y);
+    return (dx + dy) * args.delayScale + args.delayOffset;
+}
+
+bool Arch::getBudgetOverride(const NetInfo *net_info, const PortRef &sink, delay_t &budget) const { return false; }
+
+ArcBounds Arch::getRouteBoundingBox(WireId src, WireId dst) const
+{
+    ArcBounds bb;
+
+    int src_x = wires.at(src).x;
+    int src_y = wires.at(src).y;
+    int dst_x = wires.at(dst).x;
+    int dst_y = wires.at(dst).y;
+
+    bb.x0 = src_x;
+    bb.y0 = src_y;
+    bb.x1 = src_x;
+    bb.y1 = src_y;
+
+    auto extend = [&](int x, int y) {
+        bb.x0 = std::min(bb.x0, x);
+        bb.x1 = std::max(bb.x1, x);
+        bb.y0 = std::min(bb.y0, y);
+        bb.y1 = std::max(bb.y1, y);
+    };
+    extend(dst_x, dst_y);
+    return bb;
+}
+
+// ---------------------------------------------------------------
+
+bool Arch::place()
+{
+    std::string placer = str_or_default(settings, id("placer"), defaultPlacer);
+    if (placer == "heap") {
+        bool have_iobuf_or_constr = false;
+        for (auto cell : sorted(cells)) {
+            CellInfo *ci = cell.second;
+            if (ci->type == id("GENERIC_IOB") || ci->bel != BelId() || ci->attrs.count(id("BEL"))) {
+                have_iobuf_or_constr = true;
+                break;
+            }
+        }
+        bool retVal;
+        if (!have_iobuf_or_constr) {
+            log_warning("Unable to use HeAP due to a lack of IO buffers or constrained cells as anchors; reverting to "
+                        "SA.\n");
+            retVal = placer1(getCtx(), Placer1Cfg(getCtx()));
+        } else {
+            PlacerHeapCfg cfg(getCtx());
+            cfg.ioBufTypes.insert(id("GENERIC_IOB"));
+            retVal = placer_heap(getCtx(), cfg);
+        }
+        getCtx()->settings[getCtx()->id("place")] = 1;
+        archInfoToAttributes();
+        return retVal;
+    } else if (placer == "sa") {
+        bool retVal = placer1(getCtx(), Placer1Cfg(getCtx()));
+        getCtx()->settings[getCtx()->id("place")] = 1;
+        archInfoToAttributes();
+        return retVal;
+    } else {
+        log_error("Generic architecture does not support placer '%s'\n", placer.c_str());
+    }
+}
+
+bool Arch::route()
+{
+    std::string router = str_or_default(settings, id("router"), defaultRouter);
+    bool result;
+    if (router == "router1") {
+        result = router1(getCtx(), Router1Cfg(getCtx()));
+    } else if (router == "router2") {
+        router2(getCtx(), Router2Cfg(getCtx()));
+        result = true;
+    } else {
+        log_error("iCE40 architecture does not support router '%s'\n", router.c_str());
+    }
+    getCtx()->settings[getCtx()->id("route")] = 1;
+    archInfoToAttributes();
+    return result;
+}
+
+// ---------------------------------------------------------------
+
+const std::vector<GraphicElement> &Arch::getDecalGraphics(DecalId decal) const
+{
+    if (!decal_graphics.count(decal)) {
+        std::cerr << "No decal named " << decal.str(this) << std::endl;
+        log_error("No decal named %s!\n", decal.c_str(this));
+    }
+    return decal_graphics.at(decal);
+}
+
+DecalXY Arch::getBelDecal(BelId bel) const { return bels.at(bel).decalxy; }
+
+DecalXY Arch::getWireDecal(WireId wire) const { return wires.at(wire).decalxy; }
+
+DecalXY Arch::getPipDecal(PipId pip) const { return pips.at(pip).decalxy; }
+
+DecalXY Arch::getGroupDecal(GroupId group) const { return groups.at(group).decalxy; }
+
+// ---------------------------------------------------------------
+
+bool Arch::getCellDelay(const CellInfo *cell, IdString fromPort, IdString toPort, DelayInfo &delay) const
+{
+    if (!cellTiming.count(cell->name))
+        return false;
+    const auto &tmg = cellTiming.at(cell->name);
+    auto fnd = tmg.combDelays.find(CellDelayKey{fromPort, toPort});
+    if (fnd != tmg.combDelays.end()) {
+        delay = fnd->second;
+        return true;
+    } else {
+        return false;
+    }
+}
+
+// Get the port class, also setting clockPort if applicable
+TimingPortClass Arch::getPortTimingClass(const CellInfo *cell, IdString port, int &clockInfoCount) const
+{
+    if (!cellTiming.count(cell->name))
+        return TMG_IGNORE;
+    const auto &tmg = cellTiming.at(cell->name);
+    if (tmg.clockingInfo.count(port))
+        clockInfoCount = int(tmg.clockingInfo.at(port).size());
+    else
+        clockInfoCount = 0;
+    return get_or_default(tmg.portClasses, port, TMG_IGNORE);
+}
+
+TimingClockingInfo Arch::getPortClockingInfo(const CellInfo *cell, IdString port, int index) const
+{
+    NPNR_ASSERT(cellTiming.count(cell->name));
+    const auto &tmg = cellTiming.at(cell->name);
+    NPNR_ASSERT(tmg.clockingInfo.count(port));
+    return tmg.clockingInfo.at(port).at(index);
+}
+
+bool Arch::isValidBelForCell(CellInfo *cell, BelId bel) const
+{
+    std::vector<const CellInfo *> cells;
+    cells.push_back(cell);
+    Loc loc = getBelLocation(bel);
+    for (auto tbel : getBelsByTile(loc.x, loc.y)) {
+        if (tbel == bel)
+            continue;
+        CellInfo *bound = getBoundBelCell(tbel);
+        if (bound != nullptr)
+            cells.push_back(bound);
+    }
+    return cellsCompatible(cells.data(), int(cells.size()));
+}
+
+bool Arch::isBelLocationValid(BelId bel) const
+{
+    std::vector<const CellInfo *> cells;
+    Loc loc = getBelLocation(bel);
+    for (auto tbel : getBelsByTile(loc.x, loc.y)) {
+        CellInfo *bound = getBoundBelCell(tbel);
+        if (bound != nullptr)
+            cells.push_back(bound);
+    }
+    return cellsCompatible(cells.data(), int(cells.size()));
+}
+
+#ifdef WITH_HEAP
+const std::string Arch::defaultPlacer = "heap";
+#else
+const std::string Arch::defaultPlacer = "sa";
+#endif
+
+const std::vector<std::string> Arch::availablePlacers = {"sa",
+#ifdef WITH_HEAP
+                                                         "heap"
+#endif
+};
+
+const std::string Arch::defaultRouter = "router1";
+const std::vector<std::string> Arch::availableRouters = {"router1", "router2"};
+
+void Arch::assignArchInfo()
+{
+    for (auto &cell : getCtx()->cells) {
+        CellInfo *ci = cell.second.get();
+        if (ci->type == id("GENERIC_SLICE")) {
+            ci->is_slice = true;
+            ci->slice_clk = get_net_or_empty(ci, id("CLK"));
+        } else {
+            ci->is_slice = false;
+        }
+        ci->user_group = int_or_default(ci->attrs, id("PACK_GROUP"), -1);
+    }
+}
+
+bool Arch::cellsCompatible(const CellInfo **cells, int count) const
+{
+    const NetInfo *clk = nullptr;
+    int group = -1;
+    for (int i = 0; i < count; i++) {
+        const CellInfo *ci = cells[i];
+        if (ci->is_slice && ci->slice_clk != nullptr) {
+            if (clk == nullptr)
+                clk = ci->slice_clk;
+            else if (clk != ci->slice_clk)
+                return false;
+        }
+        if (ci->user_group != -1) {
+            if (group == -1)
+                group = ci->user_group;
+            else if (group != ci->user_group)
+                return false;
+        }
+    }
+    return true;
+}
+
+NEXTPNR_NAMESPACE_END
diff --git a/gowin/arch.h b/gowin/arch.h
new file mode 100644
index 00000000..177fb121
--- /dev/null
+++ b/gowin/arch.h
@@ -0,0 +1,371 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2018  Clifford Wolf <clifford@symbioticeda.com>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#ifndef NEXTPNR_H
+#error Include "arch.h" via "nextpnr.h" only.
+#endif
+
+NEXTPNR_NAMESPACE_BEGIN
+
+template <typename T> struct RelPtr
+{
+    int32_t offset;
+
+    // void set(const T *ptr) {
+    //     offset = reinterpret_cast<const char*>(ptr) -
+    //              reinterpret_cast<const char*>(this);
+    // }
+
+    const T *get() const { return reinterpret_cast<const T *>(reinterpret_cast<const char *>(this) + offset); }
+
+    const T &operator[](size_t index) const { return get()[index]; }
+
+    const T &operator*() const { return *(get()); }
+
+    const T *operator->() const { return get(); }
+
+    RelPtr(const RelPtr &) = delete;
+    RelPtr &operator=(const RelPtr &) = delete;
+};
+
+NPNR_PACKED_STRUCT(struct PairPOD {
+    uint16_t dest_id;
+    uint16_t src_id;
+});
+
+NPNR_PACKED_STRUCT(struct BelsPOD {
+    uint16_t type_id;
+    uint16_t num_ports;
+    RelPtr<PairPOD> ports;
+});
+
+NPNR_PACKED_STRUCT(struct TilePOD /*TidePOD*/ {
+    uint32_t num_bels;
+    RelPtr<BelsPOD> bels;
+    uint32_t num_pips;
+    RelPtr<PairPOD> pips;
+    uint32_t num_clock_pips;
+    RelPtr<PairPOD> clock_pips;
+    uint32_t num_aliases;
+    RelPtr<PairPOD> aliases;
+});
+
+NPNR_PACKED_STRUCT(struct GlobalAliasPOD {
+    uint16_t dest_row;
+    uint16_t dest_col;
+    uint16_t dest_id;
+    uint16_t src_row;
+    uint16_t src_col;
+    uint16_t src_id;
+});
+
+NPNR_PACKED_STRUCT(struct DatabasePOD {
+    RelPtr<char> family;
+    uint32_t version;
+    uint16_t rows;
+    uint16_t cols;
+    RelPtr<RelPtr<TilePOD>> grid;
+    uint32_t num_aliases;
+    RelPtr<GlobalAliasPOD> aliases;
+    uint16_t num_constids;
+    uint16_t num_ids;
+    RelPtr<RelPtr<char>> id_strs;
+});
+
+struct ArchArgs
+{
+    std::string device;
+    // Number of LUT inputs
+    int K = 4;
+    // y = mx + c relationship between distance and delay for interconnect
+    // delay estimates
+    double delayScale = 0.1, delayOffset = 0;
+};
+
+struct WireInfo;
+
+struct PipInfo
+{
+    IdString name, type;
+    std::map<IdString, std::string> attrs;
+    NetInfo *bound_net;
+    WireId srcWire, dstWire;
+    DelayInfo delay;
+    DecalXY decalxy;
+    Loc loc;
+};
+
+struct WireInfo
+{
+    IdString name, type;
+    std::map<IdString, std::string> attrs;
+    NetInfo *bound_net;
+    std::vector<PipId> downhill, uphill;
+    BelPin uphill_bel_pin;
+    std::vector<BelPin> downhill_bel_pins;
+    std::vector<BelPin> bel_pins;
+    DecalXY decalxy;
+    int x, y;
+};
+
+struct PinInfo
+{
+    IdString name;
+    WireId wire;
+    PortType type;
+};
+
+struct BelInfo
+{
+    IdString name, type;
+    std::map<IdString, std::string> attrs;
+    CellInfo *bound_cell;
+    std::unordered_map<IdString, PinInfo> pins;
+    DecalXY decalxy;
+    int x, y, z;
+    bool gb;
+};
+
+struct GroupInfo
+{
+    IdString name;
+    std::vector<BelId> bels;
+    std::vector<WireId> wires;
+    std::vector<PipId> pips;
+    std::vector<GroupId> groups;
+    DecalXY decalxy;
+};
+
+struct CellDelayKey
+{
+    IdString from, to;
+    inline bool operator==(const CellDelayKey &other) const { return from == other.from && to == other.to; }
+};
+
+NEXTPNR_NAMESPACE_END
+namespace std {
+template <> struct hash<NEXTPNR_NAMESPACE_PREFIX CellDelayKey>
+{
+    std::size_t operator()(const NEXTPNR_NAMESPACE_PREFIX CellDelayKey &dk) const noexcept
+    {
+        std::size_t seed = std::hash<NEXTPNR_NAMESPACE_PREFIX IdString>()(dk.from);
+        seed ^= std::hash<NEXTPNR_NAMESPACE_PREFIX IdString>()(dk.to) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
+        return seed;
+    }
+};
+} // namespace std
+NEXTPNR_NAMESPACE_BEGIN
+
+struct CellTiming
+{
+    std::unordered_map<IdString, TimingPortClass> portClasses;
+    std::unordered_map<CellDelayKey, DelayInfo> combDelays;
+    std::unordered_map<IdString, std::vector<TimingClockingInfo>> clockingInfo;
+};
+
+struct Arch : BaseCtx
+{
+    std::string family;
+    std::string device;
+    std::string package;
+    std::string speed;
+
+    std::unordered_map<IdString, WireInfo> wires;
+    std::unordered_map<IdString, PipInfo> pips;
+    std::unordered_map<IdString, BelInfo> bels;
+    std::unordered_map<GroupId, GroupInfo> groups;
+
+    // These functions include useful errors if not found
+    WireInfo &wire_info(IdString wire);
+    PipInfo &pip_info(IdString wire);
+    BelInfo &bel_info(IdString wire);
+
+    std::vector<IdString> bel_ids, wire_ids, pip_ids;
+
+    std::unordered_map<Loc, BelId> bel_by_loc;
+    std::vector<std::vector<std::vector<BelId>>> bels_by_tile;
+
+    std::unordered_map<DecalId, std::vector<GraphicElement>> decal_graphics;
+
+    int gridDimX, gridDimY;
+    std::vector<std::vector<int>> tileBelDimZ;
+    std::vector<std::vector<int>> tilePipDimZ;
+
+    std::unordered_map<IdString, CellTiming> cellTiming;
+
+    void addWire(IdString name, IdString type, int x, int y);
+    void addPip(IdString name, IdString type, IdString srcWire, IdString dstWire, DelayInfo delay, Loc loc);
+
+    void addBel(IdString name, IdString type, Loc loc, bool gb);
+    void addBelInput(IdString bel, IdString name, IdString wire);
+    void addBelOutput(IdString bel, IdString name, IdString wire);
+    void addBelInout(IdString bel, IdString name, IdString wire);
+
+    void addGroupBel(IdString group, IdString bel);
+    void addGroupWire(IdString group, IdString wire);
+    void addGroupPip(IdString group, IdString pip);
+    void addGroupGroup(IdString group, IdString grp);
+
+    void addDecalGraphic(DecalId decal, const GraphicElement &graphic);
+    void setWireDecal(WireId wire, DecalXY decalxy);
+    void setPipDecal(PipId pip, DecalXY decalxy);
+    void setBelDecal(BelId bel, DecalXY decalxy);
+    void setGroupDecal(GroupId group, DecalXY decalxy);
+
+    void setWireAttr(IdString wire, IdString key, const std::string &value);
+    void setPipAttr(IdString pip, IdString key, const std::string &value);
+    void setBelAttr(IdString bel, IdString key, const std::string &value);
+
+    void setLutK(int K);
+    void setDelayScaling(double scale, double offset);
+
+    void addCellTimingClock(IdString cell, IdString port);
+    void addCellTimingDelay(IdString cell, IdString fromPort, IdString toPort, DelayInfo delay);
+    void addCellTimingSetupHold(IdString cell, IdString port, IdString clock, DelayInfo setup, DelayInfo hold);
+    void addCellTimingClockToOut(IdString cell, IdString port, IdString clock, DelayInfo clktoq);
+
+    IdString wireToGlobal(int row, int col, const DatabasePOD* db, IdString wire);
+
+    // ---------------------------------------------------------------
+    // Common Arch API. Every arch must provide the following methods.
+
+    ArchArgs args;
+    Arch(ArchArgs args);
+
+    std::string getChipName() const { return device; }
+
+    IdString archId() const { return id("gowin"); }
+    ArchArgs archArgs() const { return args; }
+    IdString archArgsToId(ArchArgs args) const { return id("none"); }
+
+    int getGridDimX() const { return gridDimX; }
+    int getGridDimY() const { return gridDimY; }
+    int getTileBelDimZ(int x, int y) const { return tileBelDimZ[x][y]; }
+    int getTilePipDimZ(int x, int y) const { return tilePipDimZ[x][y]; }
+
+    BelId getBelByName(IdString name) const;
+    IdString getBelName(BelId bel) const;
+    Loc getBelLocation(BelId bel) const;
+    BelId getBelByLocation(Loc loc) const;
+    const std::vector<BelId> &getBelsByTile(int x, int y) const;
+    bool getBelGlobalBuf(BelId bel) const;
+    uint32_t getBelChecksum(BelId bel) const;
+    void bindBel(BelId bel, CellInfo *cell, PlaceStrength strength);
+    void unbindBel(BelId bel);
+    bool checkBelAvail(BelId bel) const;
+    CellInfo *getBoundBelCell(BelId bel) const;
+    CellInfo *getConflictingBelCell(BelId bel) const;
+    const std::vector<BelId> &getBels() const;
+    IdString getBelType(BelId bel) const;
+    const std::map<IdString, std::string> &getBelAttrs(BelId bel) const;
+    WireId getBelPinWire(BelId bel, IdString pin) const;
+    PortType getBelPinType(BelId bel, IdString pin) const;
+    std::vector<IdString> getBelPins(BelId bel) const;
+
+    WireId getWireByName(IdString name) const;
+    IdString getWireName(WireId wire) const;
+    IdString getWireType(WireId wire) const;
+    const std::map<IdString, std::string> &getWireAttrs(WireId wire) const;
+    uint32_t getWireChecksum(WireId wire) const;
+    void bindWire(WireId wire, NetInfo *net, PlaceStrength strength);
+    void unbindWire(WireId wire);
+    bool checkWireAvail(WireId wire) const;
+    NetInfo *getBoundWireNet(WireId wire) const;
+    WireId getConflictingWireWire(WireId wire) const { return wire; }
+    NetInfo *getConflictingWireNet(WireId wire) const;
+    DelayInfo getWireDelay(WireId wire) const { return DelayInfo(); }
+    const std::vector<WireId> &getWires() const;
+    const std::vector<BelPin> &getWireBelPins(WireId wire) const;
+
+    PipId getPipByName(IdString name) const;
+    IdString getPipName(PipId pip) const;
+    IdString getPipType(PipId pip) const;
+    const std::map<IdString, std::string> &getPipAttrs(PipId pip) const;
+    uint32_t getPipChecksum(PipId pip) const;
+    void bindPip(PipId pip, NetInfo *net, PlaceStrength strength);
+    void unbindPip(PipId pip);
+    bool checkPipAvail(PipId pip) const;
+    NetInfo *getBoundPipNet(PipId pip) const;
+    WireId getConflictingPipWire(PipId pip) const;
+    NetInfo *getConflictingPipNet(PipId pip) const;
+    const std::vector<PipId> &getPips() const;
+    Loc getPipLocation(PipId pip) const;
+    WireId getPipSrcWire(PipId pip) const;
+    WireId getPipDstWire(PipId pip) const;
+    DelayInfo getPipDelay(PipId pip) const;
+    const std::vector<PipId> &getPipsDownhill(WireId wire) const;
+    const std::vector<PipId> &getPipsUphill(WireId wire) const;
+
+    GroupId getGroupByName(IdString name) const;
+    IdString getGroupName(GroupId group) const;
+    std::vector<GroupId> getGroups() const;
+    const std::vector<BelId> &getGroupBels(GroupId group) const;
+    const std::vector<WireId> &getGroupWires(GroupId group) const;
+    const std::vector<PipId> &getGroupPips(GroupId group) const;
+    const std::vector<GroupId> &getGroupGroups(GroupId group) const;
+
+    delay_t estimateDelay(WireId src, WireId dst) const;
+    delay_t predictDelay(const NetInfo *net_info, const PortRef &sink) const;
+    delay_t getDelayEpsilon() const { return 0.001; }
+    delay_t getRipupDelayPenalty() const { return 0.015; }
+    float getDelayNS(delay_t v) const { return v; }
+
+    DelayInfo getDelayFromNS(float ns) const
+    {
+        DelayInfo del;
+        del.delay = ns;
+        return del;
+    }
+
+    uint32_t getDelayChecksum(delay_t v) const { return 0; }
+    bool getBudgetOverride(const NetInfo *net_info, const PortRef &sink, delay_t &budget) const;
+
+    ArcBounds getRouteBoundingBox(WireId src, WireId dst) const;
+
+    bool pack();
+    bool place();
+    bool route();
+
+    const std::vector<GraphicElement> &getDecalGraphics(DecalId decal) const;
+    DecalXY getBelDecal(BelId bel) const;
+    DecalXY getWireDecal(WireId wire) const;
+    DecalXY getPipDecal(PipId pip) const;
+    DecalXY getGroupDecal(GroupId group) const;
+
+    bool getCellDelay(const CellInfo *cell, IdString fromPort, IdString toPort, DelayInfo &delay) const;
+    // Get the port class, also setting clockInfoCount to the number of TimingClockingInfos associated with a port
+    TimingPortClass getPortTimingClass(const CellInfo *cell, IdString port, int &clockInfoCount) const;
+    // Get the TimingClockingInfo of a port
+    TimingClockingInfo getPortClockingInfo(const CellInfo *cell, IdString port, int index) const;
+
+    bool isValidBelForCell(CellInfo *cell, BelId bel) const;
+    bool isBelLocationValid(BelId bel) const;
+
+    static const std::string defaultPlacer;
+    static const std::vector<std::string> availablePlacers;
+    static const std::string defaultRouter;
+    static const std::vector<std::string> availableRouters;
+
+    // ---------------------------------------------------------------
+    // Internal usage
+    void assignArchInfo();
+    bool cellsCompatible(const CellInfo **cells, int count) const;
+};
+
+NEXTPNR_NAMESPACE_END
diff --git a/gowin/arch_pybindings.cc b/gowin/arch_pybindings.cc
new file mode 100644
index 00000000..7f7229fd
--- /dev/null
+++ b/gowin/arch_pybindings.cc
@@ -0,0 +1,237 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2018  Clifford Wolf <clifford@symbioticeda.com>
+ *  Copyright (C) 2018  David Shah <dave@ds0.me>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#ifndef NO_PYTHON
+
+#include "arch_pybindings.h"
+#include "nextpnr.h"
+#include "pybindings.h"
+#include "pywrappers.h"
+
+using namespace pybind11::literals;
+
+NEXTPNR_NAMESPACE_BEGIN
+namespace PythonConversion {
+template <> struct string_converter<const IdString &>
+{
+    const IdString &from_str(Context *ctx, std::string name) { NPNR_ASSERT_FALSE("unsupported"); }
+
+    std::string to_str(Context *ctx, const IdString &id) { return id.str(ctx); }
+};
+} // namespace PythonConversion
+
+void arch_wrap_python(py::module &m)
+{
+    using namespace PythonConversion;
+
+    auto arch_cls = py::class_<Arch, BaseCtx>(m, "Arch").def(py::init<ArchArgs>());
+
+    auto dxy_cls = py::class_<ContextualWrapper<DecalXY>>(m, "DecalXY_");
+    readwrite_wrapper<DecalXY, decltype(&DecalXY::decal), &DecalXY::decal, conv_to_str<DecalId>,
+                      conv_from_str<DecalId>>::def_wrap(dxy_cls, "decal");
+    readwrite_wrapper<DecalXY, decltype(&DecalXY::x), &DecalXY::x, pass_through<float>, pass_through<float>>::def_wrap(
+            dxy_cls, "x");
+    readwrite_wrapper<DecalXY, decltype(&DecalXY::y), &DecalXY::y, pass_through<float>, pass_through<float>>::def_wrap(
+            dxy_cls, "y");
+
+    auto ctx_cls = py::class_<Context, Arch>(m, "Context")
+                           .def("checksum", &Context::checksum)
+                           .def("pack", &Context::pack)
+                           .def("place", &Context::place)
+                           .def("route", &Context::route);
+
+    py::class_<BelPin>(m, "BelPin").def_readwrite("bel", &BelPin::bel).def_readwrite("pin", &BelPin::pin);
+
+    py::class_<DelayInfo>(m, "DelayInfo").def("maxDelay", &DelayInfo::maxDelay).def("minDelay", &DelayInfo::minDelay);
+
+    fn_wrapper_1a<Context, decltype(&Context::getBelType), &Context::getBelType, conv_to_str<IdString>,
+                  conv_from_str<BelId>>::def_wrap(ctx_cls, "getBelType");
+    fn_wrapper_1a<Context, decltype(&Context::checkBelAvail), &Context::checkBelAvail, pass_through<bool>,
+                  conv_from_str<BelId>>::def_wrap(ctx_cls, "checkBelAvail");
+    fn_wrapper_1a<Context, decltype(&Context::getBelChecksum), &Context::getBelChecksum, pass_through<uint32_t>,
+                  conv_from_str<BelId>>::def_wrap(ctx_cls, "getBelChecksum");
+    fn_wrapper_3a_v<Context, decltype(&Context::bindBel), &Context::bindBel, conv_from_str<BelId>,
+                    addr_and_unwrap<CellInfo>, pass_through<PlaceStrength>>::def_wrap(ctx_cls, "bindBel");
+    fn_wrapper_1a_v<Context, decltype(&Context::unbindBel), &Context::unbindBel, conv_from_str<BelId>>::def_wrap(
+            ctx_cls, "unbindBel");
+    fn_wrapper_1a<Context, decltype(&Context::getBoundBelCell), &Context::getBoundBelCell, deref_and_wrap<CellInfo>,
+                  conv_from_str<BelId>>::def_wrap(ctx_cls, "getBoundBelCell");
+    fn_wrapper_1a<Context, decltype(&Context::getConflictingBelCell), &Context::getConflictingBelCell,
+                  deref_and_wrap<CellInfo>, conv_from_str<BelId>>::def_wrap(ctx_cls, "getConflictingBelCell");
+    fn_wrapper_0a<Context, decltype(&Context::getBels), &Context::getBels,
+                  wrap_context<const std::vector<BelId> &>>::def_wrap(ctx_cls, "getBels");
+
+    fn_wrapper_2a<Context, decltype(&Context::getBelPinWire), &Context::getBelPinWire, conv_to_str<WireId>,
+                  conv_from_str<BelId>, conv_from_str<IdString>>::def_wrap(ctx_cls, "getBelPinWire");
+    fn_wrapper_1a<Context, decltype(&Context::getWireBelPins), &Context::getWireBelPins,
+                  wrap_context<const std::vector<BelPin> &>, conv_from_str<WireId>>::def_wrap(ctx_cls,
+                                                                                              "getWireBelPins");
+
+    fn_wrapper_1a<Context, decltype(&Context::getWireChecksum), &Context::getWireChecksum, pass_through<uint32_t>,
+                  conv_from_str<WireId>>::def_wrap(ctx_cls, "getWireChecksum");
+    fn_wrapper_3a_v<Context, decltype(&Context::bindWire), &Context::bindWire, conv_from_str<WireId>,
+                    addr_and_unwrap<NetInfo>, pass_through<PlaceStrength>>::def_wrap(ctx_cls, "bindWire");
+    fn_wrapper_1a_v<Context, decltype(&Context::unbindWire), &Context::unbindWire, conv_from_str<WireId>>::def_wrap(
+            ctx_cls, "unbindWire");
+    fn_wrapper_1a<Context, decltype(&Context::checkWireAvail), &Context::checkWireAvail, pass_through<bool>,
+                  conv_from_str<WireId>>::def_wrap(ctx_cls, "checkWireAvail");
+    fn_wrapper_1a<Context, decltype(&Context::getBoundWireNet), &Context::getBoundWireNet, deref_and_wrap<NetInfo>,
+                  conv_from_str<WireId>>::def_wrap(ctx_cls, "getBoundWireNet");
+    fn_wrapper_1a<Context, decltype(&Context::getConflictingWireNet), &Context::getConflictingWireNet,
+                  deref_and_wrap<NetInfo>, conv_from_str<WireId>>::def_wrap(ctx_cls, "getConflictingWireNet");
+
+    fn_wrapper_0a<Context, decltype(&Context::getWires), &Context::getWires,
+                  wrap_context<const std::vector<WireId> &>>::def_wrap(ctx_cls, "getWires");
+
+    fn_wrapper_0a<Context, decltype(&Context::getPips), &Context::getPips,
+                  wrap_context<const std::vector<PipId> &>>::def_wrap(ctx_cls, "getPips");
+    fn_wrapper_1a<Context, decltype(&Context::getPipChecksum), &Context::getPipChecksum, pass_through<uint32_t>,
+                  conv_from_str<PipId>>::def_wrap(ctx_cls, "getPipChecksum");
+    fn_wrapper_3a_v<Context, decltype(&Context::bindPip), &Context::bindPip, conv_from_str<PipId>,
+                    addr_and_unwrap<NetInfo>, pass_through<PlaceStrength>>::def_wrap(ctx_cls, "bindPip");
+    fn_wrapper_1a_v<Context, decltype(&Context::unbindPip), &Context::unbindPip, conv_from_str<PipId>>::def_wrap(
+            ctx_cls, "unbindPip");
+    fn_wrapper_1a<Context, decltype(&Context::checkPipAvail), &Context::checkPipAvail, pass_through<bool>,
+                  conv_from_str<PipId>>::def_wrap(ctx_cls, "checkPipAvail");
+    fn_wrapper_1a<Context, decltype(&Context::getBoundPipNet), &Context::getBoundPipNet, deref_and_wrap<NetInfo>,
+                  conv_from_str<PipId>>::def_wrap(ctx_cls, "getBoundPipNet");
+    fn_wrapper_1a<Context, decltype(&Context::getConflictingPipNet), &Context::getConflictingPipNet,
+                  deref_and_wrap<NetInfo>, conv_from_str<PipId>>::def_wrap(ctx_cls, "getConflictingPipNet");
+
+    fn_wrapper_1a<Context, decltype(&Context::getPipsDownhill), &Context::getPipsDownhill,
+                  wrap_context<const std::vector<PipId> &>, conv_from_str<WireId>>::def_wrap(ctx_cls,
+                                                                                             "getPipsDownhill");
+    fn_wrapper_1a<Context, decltype(&Context::getPipsUphill), &Context::getPipsUphill,
+                  wrap_context<const std::vector<PipId> &>, conv_from_str<WireId>>::def_wrap(ctx_cls, "getPipsUphill");
+
+    fn_wrapper_1a<Context, decltype(&Context::getPipSrcWire), &Context::getPipSrcWire, conv_to_str<WireId>,
+                  conv_from_str<PipId>>::def_wrap(ctx_cls, "getPipSrcWire");
+    fn_wrapper_1a<Context, decltype(&Context::getPipDstWire), &Context::getPipDstWire, conv_to_str<WireId>,
+                  conv_from_str<PipId>>::def_wrap(ctx_cls, "getPipDstWire");
+    fn_wrapper_1a<Context, decltype(&Context::getPipDelay), &Context::getPipDelay, pass_through<DelayInfo>,
+                  conv_from_str<PipId>>::def_wrap(ctx_cls, "getPipDelay");
+
+    fn_wrapper_1a<Context, decltype(&Context::getDelayFromNS), &Context::getDelayFromNS, pass_through<DelayInfo>,
+                  pass_through<double>>::def_wrap(ctx_cls, "getDelayFromNS");
+
+    fn_wrapper_0a<Context, decltype(&Context::getChipName), &Context::getChipName, pass_through<std::string>>::def_wrap(
+            ctx_cls, "getChipName");
+    fn_wrapper_0a<Context, decltype(&Context::archId), &Context::archId, conv_to_str<IdString>>::def_wrap(ctx_cls,
+                                                                                                          "archId");
+
+    fn_wrapper_3a<Context, decltype(&Context::constructDecalXY), &Context::constructDecalXY, wrap_context<DecalXY>,
+                  conv_from_str<DecalId>, pass_through<float>, pass_through<float>>::def_wrap(ctx_cls, "DecalXY");
+
+    typedef std::unordered_map<IdString, std::unique_ptr<CellInfo>> CellMap;
+    typedef std::unordered_map<IdString, std::unique_ptr<NetInfo>> NetMap;
+    typedef std::unordered_map<IdString, HierarchicalCell> HierarchyMap;
+
+    readonly_wrapper<Context, decltype(&Context::cells), &Context::cells, wrap_context<CellMap &>>::def_wrap(ctx_cls,
+                                                                                                             "cells");
+    readonly_wrapper<Context, decltype(&Context::nets), &Context::nets, wrap_context<NetMap &>>::def_wrap(ctx_cls,
+                                                                                                          "nets");
+
+    fn_wrapper_2a_v<Context, decltype(&Context::addClock), &Context::addClock, conv_from_str<IdString>,
+                    pass_through<float>>::def_wrap(ctx_cls, "addClock");
+
+    // Generic arch construction API
+    fn_wrapper_4a_v<Context, decltype(&Context::addWire), &Context::addWire, conv_from_str<IdString>,
+                    conv_from_str<IdString>, pass_through<int>, pass_through<int>>::def_wrap(ctx_cls, "addWire",
+                                                                                             "name"_a, "type"_a, "x"_a,
+                                                                                             "y"_a);
+    fn_wrapper_6a_v<Context, decltype(&Context::addPip), &Context::addPip, conv_from_str<IdString>,
+                    conv_from_str<IdString>, conv_from_str<IdString>, conv_from_str<IdString>, pass_through<DelayInfo>,
+                    pass_through<Loc>>::def_wrap(ctx_cls, "addPip", "name"_a, "type"_a, "srcWire"_a, "dstWire"_a,
+                                                 "delay"_a, "loc"_a);
+
+    fn_wrapper_4a_v<Context, decltype(&Context::addBel), &Context::addBel, conv_from_str<IdString>,
+                    conv_from_str<IdString>, pass_through<Loc>, pass_through<bool>>::def_wrap(ctx_cls, "addBel",
+                                                                                              "name"_a, "type"_a,
+                                                                                              "loc"_a, "gb"_a);
+    fn_wrapper_3a_v<Context, decltype(&Context::addBelInput), &Context::addBelInput, conv_from_str<IdString>,
+                    conv_from_str<IdString>, conv_from_str<IdString>>::def_wrap(ctx_cls, "addBelInput", "bel"_a,
+                                                                                "name"_a, "wire"_a);
+    fn_wrapper_3a_v<Context, decltype(&Context::addBelOutput), &Context::addBelOutput, conv_from_str<IdString>,
+                    conv_from_str<IdString>, conv_from_str<IdString>>::def_wrap(ctx_cls, "addBelOutput", "bel"_a,
+                                                                                "name"_a, "wire"_a);
+    fn_wrapper_3a_v<Context, decltype(&Context::addBelInout), &Context::addBelInout, conv_from_str<IdString>,
+                    conv_from_str<IdString>, conv_from_str<IdString>>::def_wrap(ctx_cls, "addBelInout", "bel"_a,
+                                                                                "name"_a, "wire"_a);
+
+    fn_wrapper_2a_v<Context, decltype(&Context::addGroupBel), &Context::addGroupBel, conv_from_str<IdString>,
+                    conv_from_str<IdString>>::def_wrap(ctx_cls, "addGroupBel", "group"_a, "bel"_a);
+    fn_wrapper_2a_v<Context, decltype(&Context::addGroupWire), &Context::addGroupWire, conv_from_str<IdString>,
+                    conv_from_str<IdString>>::def_wrap(ctx_cls, "addGroupWire", "group"_a, "wire"_a);
+    fn_wrapper_2a_v<Context, decltype(&Context::addGroupPip), &Context::addGroupPip, conv_from_str<IdString>,
+                    conv_from_str<IdString>>::def_wrap(ctx_cls, "addGroupPip", "group"_a, "pip"_a);
+    fn_wrapper_2a_v<Context, decltype(&Context::addGroupGroup), &Context::addGroupPip, conv_from_str<IdString>,
+                    conv_from_str<IdString>>::def_wrap(ctx_cls, "addGroupGroup", "group"_a, "grp"_a);
+
+    fn_wrapper_2a_v<Context, decltype(&Context::addDecalGraphic), &Context::addDecalGraphic, conv_from_str<DecalId>,
+                    pass_through<GraphicElement>>::def_wrap(ctx_cls, "addDecalGraphic", (py::arg("decal"), "graphic"));
+    fn_wrapper_2a_v<Context, decltype(&Context::setWireDecal), &Context::setWireDecal, conv_from_str<DecalId>,
+                    unwrap_context<DecalXY>>::def_wrap(ctx_cls, "setWireDecal", "wire"_a, "decalxy"_a);
+    fn_wrapper_2a_v<Context, decltype(&Context::setPipDecal), &Context::setPipDecal, conv_from_str<DecalId>,
+                    unwrap_context<DecalXY>>::def_wrap(ctx_cls, "setPipDecal", "pip"_a, "decalxy"_a);
+    fn_wrapper_2a_v<Context, decltype(&Context::setBelDecal), &Context::setBelDecal, conv_from_str<DecalId>,
+                    unwrap_context<DecalXY>>::def_wrap(ctx_cls, "setBelDecal", "bel"_a, "decalxy"_a);
+    fn_wrapper_2a_v<Context, decltype(&Context::setGroupDecal), &Context::setGroupDecal, conv_from_str<DecalId>,
+                    unwrap_context<DecalXY>>::def_wrap(ctx_cls, "setGroupDecal", "group"_a, "decalxy"_a);
+
+    fn_wrapper_3a_v<Context, decltype(&Context::setWireAttr), &Context::setWireAttr, conv_from_str<DecalId>,
+                    conv_from_str<IdString>, pass_through<std::string>>::def_wrap(ctx_cls, "setWireAttr", "wire"_a,
+                                                                                  "key"_a, "value"_a);
+    fn_wrapper_3a_v<Context, decltype(&Context::setBelAttr), &Context::setBelAttr, conv_from_str<DecalId>,
+                    conv_from_str<IdString>, pass_through<std::string>>::def_wrap(ctx_cls, "setBelAttr", "bel"_a,
+                                                                                  "key"_a, "value"_a);
+    fn_wrapper_3a_v<Context, decltype(&Context::setPipAttr), &Context::setPipAttr, conv_from_str<DecalId>,
+                    conv_from_str<IdString>, pass_through<std::string>>::def_wrap(ctx_cls, "setPipAttr", "pip"_a,
+                                                                                  "key"_a, "value"_a);
+
+    fn_wrapper_1a_v<Context, decltype(&Context::setLutK), &Context::setLutK, pass_through<int>>::def_wrap(
+            ctx_cls, "setLutK", "K"_a);
+    fn_wrapper_2a_v<Context, decltype(&Context::setDelayScaling), &Context::setDelayScaling, pass_through<double>,
+                    pass_through<double>>::def_wrap(ctx_cls, "setDelayScaling", "scale"_a, "offset"_a);
+
+    fn_wrapper_2a_v<Context, decltype(&Context::addCellTimingClock), &Context::addCellTimingClock,
+                    conv_from_str<IdString>, conv_from_str<IdString>>::def_wrap(ctx_cls, "addCellTimingClock", "cell"_a,
+                                                                                "port"_a);
+    fn_wrapper_4a_v<Context, decltype(&Context::addCellTimingDelay), &Context::addCellTimingDelay,
+                    conv_from_str<IdString>, conv_from_str<IdString>, conv_from_str<IdString>,
+                    pass_through<DelayInfo>>::def_wrap(ctx_cls, "addCellTimingDelay", "cell"_a, "fromPort"_a,
+                                                       "toPort"_a, "delay"_a);
+    fn_wrapper_5a_v<Context, decltype(&Context::addCellTimingSetupHold), &Context::addCellTimingSetupHold,
+                    conv_from_str<IdString>, conv_from_str<IdString>, conv_from_str<IdString>, pass_through<DelayInfo>,
+                    pass_through<DelayInfo>>::def_wrap(ctx_cls, "addCellTimingSetupHold", "cell"_a, "port"_a, "clock"_a,
+                                                       "setup"_a, "hold"_a);
+    fn_wrapper_4a_v<Context, decltype(&Context::addCellTimingClockToOut), &Context::addCellTimingClockToOut,
+                    conv_from_str<IdString>, conv_from_str<IdString>, conv_from_str<IdString>,
+                    pass_through<DelayInfo>>::def_wrap(ctx_cls, "addCellTimingClockToOut", "cell"_a, "port"_a,
+                                                       "clock"_a, "clktoq"_a);
+
+    WRAP_MAP_UPTR(m, CellMap, "IdCellMap");
+    WRAP_MAP_UPTR(m, NetMap, "IdNetMap");
+    WRAP_MAP(m, HierarchyMap, wrap_context<HierarchicalCell &>, "HierarchyMap");
+    WRAP_VECTOR(m, const std::vector<IdString>, conv_to_str<IdString>);
+}
+
+NEXTPNR_NAMESPACE_END
+
+#endif
diff --git a/gowin/arch_pybindings.h b/gowin/arch_pybindings.h
new file mode 100644
index 00000000..f7f07529
--- /dev/null
+++ b/gowin/arch_pybindings.h
@@ -0,0 +1,31 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2018  Clifford Wolf <clifford@symbioticeda.com>
+ *  Copyright (C) 2018  David Shah <david@symbioticeda.com>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+#ifndef ARCH_PYBINDINGS_H
+#define ARCH_PYBINDINGS_H
+#ifndef NO_PYTHON
+
+#include "nextpnr.h"
+#include "pybindings.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+
+NEXTPNR_NAMESPACE_END
+#endif
+#endif
diff --git a/gowin/archdefs.h b/gowin/archdefs.h
new file mode 100644
index 00000000..978c9c9b
--- /dev/null
+++ b/gowin/archdefs.h
@@ -0,0 +1,72 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2018  Clifford Wolf <clifford@symbioticeda.com>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#ifndef NEXTPNR_H
+#error Include "archdefs.h" via "nextpnr.h" only.
+#endif
+
+NEXTPNR_NAMESPACE_BEGIN
+
+typedef float delay_t;
+
+struct DelayInfo
+{
+    delay_t delay = 0;
+
+    delay_t minRaiseDelay() const { return delay; }
+    delay_t maxRaiseDelay() const { return delay; }
+
+    delay_t minFallDelay() const { return delay; }
+    delay_t maxFallDelay() const { return delay; }
+
+    delay_t minDelay() const { return delay; }
+    delay_t maxDelay() const { return delay; }
+
+    DelayInfo operator+(const DelayInfo &other) const
+    {
+        DelayInfo ret;
+        ret.delay = this->delay + other.delay;
+        return ret;
+    }
+};
+
+typedef IdString BelId;
+typedef IdString WireId;
+typedef IdString PipId;
+typedef IdString GroupId;
+typedef IdString DecalId;
+
+struct ArchNetInfo
+{
+};
+
+struct NetInfo;
+
+struct ArchCellInfo
+{
+    // Custom grouping set via "PACK_GROUP" attribute. All cells with the same group
+    // value may share a tile (-1 = don't care, default if not set)
+    int user_group;
+    // Is a slice type primitive
+    bool is_slice;
+    // Only packing rule for slice type primitives is a single clock per tile
+    const NetInfo *slice_clk;
+};
+
+NEXTPNR_NAMESPACE_END
diff --git a/gowin/cells.cc b/gowin/cells.cc
new file mode 100644
index 00000000..c4421f90
--- /dev/null
+++ b/gowin/cells.cc
@@ -0,0 +1,147 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2019  David Shah <david@symbioticeda.com>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "cells.h"
+#include "design_utils.h"
+#include "log.h"
+#include "util.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+
+void add_port(const Context *ctx, CellInfo *cell, std::string name, PortType dir)
+{
+    IdString id = ctx->id(name);
+    NPNR_ASSERT(cell->ports.count(id) == 0);
+    cell->ports[id] = PortInfo{id, nullptr, dir};
+}
+
+std::unique_ptr<CellInfo> create_generic_cell(Context *ctx, IdString type, std::string name)
+{
+    static int auto_idx = 0;
+    std::unique_ptr<CellInfo> new_cell = std::unique_ptr<CellInfo>(new CellInfo());
+    if (name.empty()) {
+        new_cell->name = ctx->id("$nextpnr_" + type.str(ctx) + "_" + std::to_string(auto_idx++));
+    } else {
+        new_cell->name = ctx->id(name);
+    }
+    new_cell->type = type;
+    if (type == ctx->id("GENERIC_SLICE")) {
+        new_cell->params[ctx->id("K")] = ctx->args.K;
+        new_cell->params[ctx->id("INIT")] = 0;
+        new_cell->params[ctx->id("FF_USED")] = 0;
+
+        for (int i = 0; i < ctx->args.K; i++)
+            add_port(ctx, new_cell.get(), "I[" + std::to_string(i) + "]", PORT_IN);
+
+        add_port(ctx, new_cell.get(), "CLK", PORT_IN);
+
+        add_port(ctx, new_cell.get(), "F", PORT_OUT);
+        add_port(ctx, new_cell.get(), "Q", PORT_OUT);
+    } else if (type == ctx->id("GENERIC_IOB")) {
+        new_cell->params[ctx->id("INPUT_USED")] = 0;
+        new_cell->params[ctx->id("OUTPUT_USED")] = 0;
+        new_cell->params[ctx->id("ENABLE_USED")] = 0;
+
+        add_port(ctx, new_cell.get(), "PAD", PORT_INOUT);
+        add_port(ctx, new_cell.get(), "I", PORT_IN);
+        add_port(ctx, new_cell.get(), "EN", PORT_IN);
+        add_port(ctx, new_cell.get(), "O", PORT_OUT);
+    } else {
+        log_error("unable to create generic cell of type %s", type.c_str(ctx));
+    }
+    return new_cell;
+}
+
+void lut_to_lc(const Context *ctx, CellInfo *lut, CellInfo *lc, bool no_dff)
+{
+    lc->params[ctx->id("INIT")] = lut->params[ctx->id("INIT")];
+
+    int lut_k = int_or_default(lut->params, ctx->id("K"), 4);
+    NPNR_ASSERT(lut_k <= ctx->args.K);
+
+    for (int i = 0; i < lut_k; i++) {
+        IdString port = ctx->id("I[" + std::to_string(i) + "]");
+        replace_port(lut, port, lc, port);
+    }
+
+    if (no_dff) {
+        lc->params[ctx->id("FF_USED")] = 0;
+        replace_port(lut, ctx->id("Q"), lc, ctx->id("F"));
+    }
+}
+
+void dff_to_lc(const Context *ctx, CellInfo *dff, CellInfo *lc, bool pass_thru_lut)
+{
+    lc->params[ctx->id("FF_USED")] = 1;
+    replace_port(dff, ctx->id("CLK"), lc, ctx->id("CLK"));
+
+    if (pass_thru_lut) {
+        // Fill LUT with alternating 10
+        const int init_size = 1 << lc->params[ctx->id("K")].as_int64();
+        std::string init;
+        init.reserve(init_size);
+        for (int i = 0; i < init_size; i += 2)
+            init.append("10");
+        lc->params[ctx->id("INIT")] = Property::from_string(init);
+
+        replace_port(dff, ctx->id("D"), lc, ctx->id("I[0]"));
+    }
+
+    replace_port(dff, ctx->id("Q"), lc, ctx->id("Q"));
+}
+
+void nxio_to_iob(Context *ctx, CellInfo *nxio, CellInfo *iob, std::unordered_set<IdString> &todelete_cells)
+{
+    if (nxio->type == ctx->id("$nextpnr_ibuf")) {
+        iob->params[ctx->id("INPUT_USED")] = 1;
+        replace_port(nxio, ctx->id("O"), iob, ctx->id("O"));
+    } else if (nxio->type == ctx->id("$nextpnr_obuf")) {
+        iob->params[ctx->id("OUTPUT_USED")] = 1;
+        replace_port(nxio, ctx->id("I"), iob, ctx->id("I"));
+    } else if (nxio->type == ctx->id("$nextpnr_iobuf")) {
+        // N.B. tristate will be dealt with below
+        iob->params[ctx->id("INPUT_USED")] = 1;
+        iob->params[ctx->id("OUTPUT_USED")] = 1;
+        replace_port(nxio, ctx->id("I"), iob, ctx->id("I"));
+        replace_port(nxio, ctx->id("O"), iob, ctx->id("O"));
+    } else {
+        NPNR_ASSERT(false);
+    }
+    NetInfo *donet = iob->ports.at(ctx->id("I")).net;
+    CellInfo *tbuf = net_driven_by(
+            ctx, donet, [](const Context *ctx, const CellInfo *cell) { return cell->type == ctx->id("$_TBUF_"); },
+            ctx->id("Y"));
+    if (tbuf) {
+        iob->params[ctx->id("ENABLE_USED")] = 1;
+        replace_port(tbuf, ctx->id("A"), iob, ctx->id("I"));
+        replace_port(tbuf, ctx->id("E"), iob, ctx->id("EN"));
+
+        if (donet->users.size() > 1) {
+            for (auto user : donet->users)
+                log_info("     remaining tristate user: %s.%s\n", user.cell->name.c_str(ctx), user.port.c_str(ctx));
+            log_error("unsupported tristate IO pattern for IO buffer '%s', "
+                      "instantiate GENERIC_IOB manually to ensure correct behaviour\n",
+                      nxio->name.c_str(ctx));
+        }
+        ctx->nets.erase(donet->name);
+        todelete_cells.insert(tbuf->name);
+    }
+}
+
+NEXTPNR_NAMESPACE_END
diff --git a/gowin/cells.h b/gowin/cells.h
new file mode 100644
index 00000000..646d738d
--- /dev/null
+++ b/gowin/cells.h
@@ -0,0 +1,55 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2019  David Shah <david@symbioticeda.com>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "nextpnr.h"
+
+#ifndef GENERIC_CELLS_H
+#define GENERIC_CELLS_H
+
+NEXTPNR_NAMESPACE_BEGIN
+
+// Create a generic arch cell and return it
+// Name will be automatically assigned if not specified
+std::unique_ptr<CellInfo> create_generic_cell(Context *ctx, IdString type, std::string name = "");
+
+// Return true if a cell is a LUT
+inline bool is_lut(const BaseCtx *ctx, const CellInfo *cell) { return cell->type == ctx->id("LUT"); }
+
+// Return true if a cell is a flipflop
+inline bool is_ff(const BaseCtx *ctx, const CellInfo *cell) { return cell->type == ctx->id("DFF"); }
+
+inline bool is_lc(const BaseCtx *ctx, const CellInfo *cell) { return cell->type == ctx->id("GENERIC_SLICE"); }
+
+// Convert a LUT primitive to (part of) an GENERIC_SLICE, swapping ports
+// as needed. Set no_dff if a DFF is not being used, so that the output
+// can be reconnected
+void lut_to_lc(const Context *ctx, CellInfo *lut, CellInfo *lc, bool no_dff = true);
+
+// Convert a DFF primitive to (part of) an GENERIC_SLICE, setting parameters
+// and reconnecting signals as necessary. If pass_thru_lut is True, the LUT will
+// be configured as pass through and D connected to I0, otherwise D will be
+// ignored
+void dff_to_lc(const Context *ctx, CellInfo *dff, CellInfo *lc, bool pass_thru_lut = false);
+
+// Convert a nextpnr IO buffer to a GENERIC_IOB
+void nxio_to_iob(Context *ctx, CellInfo *nxio, CellInfo *sbio, std::unordered_set<IdString> &todelete_cells);
+
+NEXTPNR_NAMESPACE_END
+
+#endif
diff --git a/gowin/family.cmake b/gowin/family.cmake
new file mode 100644
index 00000000..be607e6a
--- /dev/null
+++ b/gowin/family.cmake
@@ -0,0 +1,53 @@
+add_subdirectory(${family})
+message(STATUS "Using Gowin chipdb: ${GOWIN_CHIPDB}")
+
+set(chipdb_sources)
+set(chipdb_binaries)
+file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/${family}/chipdb)
+foreach(device ${GOWIN_DEVICES})
+    set(chipdb_bba ${GOWIN_CHIPDB}/chipdb-${device}.bba)
+    set(chipdb_bin ${family}/chipdb/chipdb-${device}.bin)
+    set(chipdb_cc  ${family}/chipdb/chipdb-${device}.cc)
+    if(BBASM_MODE STREQUAL "binary")
+        add_custom_command(
+            OUTPUT ${chipdb_bin}
+            COMMAND bbasm ${BBASM_ENDIAN_FLAG} ${chipdb_bba} ${chipdb_bin}
+            DEPENDS bbasm chipdb-${family}-bbas ${chipdb_bba})
+        list(APPEND chipdb_binaries ${chipdb_bin})
+    elseif(BBASM_MODE STREQUAL "embed")
+        add_custom_command(
+            OUTPUT ${chipdb_cc} ${chipdb_bin}
+            COMMAND bbasm ${BBASM_ENDIAN_FLAG} --e ${chipdb_bba} ${chipdb_cc} ${chipdb_bin}
+            DEPENDS bbasm chipdb-${family}-bbas ${chipdb_bba})
+        list(APPEND chipdb_sources ${chipdb_cc})
+        list(APPEND chipdb_binaries ${chipdb_bin})
+    elseif(BBASM_MODE STREQUAL "string")
+        add_custom_command(
+            OUTPUT ${chipdb_cc}
+            COMMAND bbasm ${BBASM_ENDIAN_FLAG} --c ${chipdb_bba} ${chipdb_cc}
+            DEPENDS bbasm chipdb-${family}-bbas ${chipdb_bba})
+        list(APPEND chipdb_sources ${chipdb_cc})
+    endif()
+endforeach()
+if(WIN32)
+    set(chipdb_rc ${CMAKE_CURRENT_BINARY_DIR}/${family}/resource/chipdb.rc)
+    list(APPEND chipdb_sources ${chipdb_rc})
+
+    file(WRITE ${chipdb_rc})
+    foreach(device ${GOWIN_DEVICES})
+        file(APPEND ${chipdb_rc}
+             "${family}/chipdb-${device}.bin RCDATA \"${CMAKE_CURRENT_BINARY_DIR}/${family}/chipdb/chipdb-${device}.bin\"")
+    endforeach()
+endif()
+
+add_custom_target(chipdb-${family}-bins DEPENDS ${chipdb_sources} ${chipdb_binaries})
+
+add_library(chipdb-${family} OBJECT ${GOWIN_CHIPDB} ${chipdb_sources})
+add_dependencies(chipdb-${family} chipdb-${family}-bins)
+target_compile_options(chipdb-${family} PRIVATE -g0 -O0 -w)
+target_compile_definitions(chipdb-${family} PRIVATE NEXTPNR_NAMESPACE=nextpnr_${family})
+target_include_directories(chipdb-${family} PRIVATE ${family})
+
+foreach(family_target ${family_targets})
+    target_sources(${family_target} PRIVATE $<TARGET_OBJECTS:chipdb-${family}>)
+endforeach()
diff --git a/gowin/main.cc b/gowin/main.cc
new file mode 100644
index 00000000..020d8882
--- /dev/null
+++ b/gowin/main.cc
@@ -0,0 +1,79 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2018  Clifford Wolf <clifford@symbioticeda.com>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#ifdef MAIN_EXECUTABLE
+
+#include <fstream>
+#include "command.h"
+#include "design_utils.h"
+#include "log.h"
+#include "timing.h"
+
+USING_NEXTPNR_NAMESPACE
+
+class GowinCommandHandler : public CommandHandler
+{
+  public:
+    GowinCommandHandler(int argc, char **argv);
+    virtual ~GowinCommandHandler(){};
+    std::unique_ptr<Context> createContext(std::unordered_map<std::string, Property> &values) override;
+    void setupArchContext(Context *ctx) override{};
+    void customAfterLoad(Context *ctx) override;
+
+  protected:
+    po::options_description getArchOptions() override;
+};
+
+GowinCommandHandler::GowinCommandHandler(int argc, char **argv) : CommandHandler(argc, argv) {}
+
+po::options_description GowinCommandHandler::getArchOptions()
+{
+    po::options_description specific("Architecture specific options");
+    specific.add_options()("device", po::value<std::string>(), "device name");
+    specific.add_options()("family", po::value<std::string>(), "device family");
+    specific.add_options()("package", po::value<std::string>(), "device package");
+    specific.add_options()("speed", po::value<std::string>(), "device speed grade");
+    specific.add_options()("pdc", po::value<std::string>(), "physical constraints file");
+    return specific;
+}
+
+std::unique_ptr<Context> GowinCommandHandler::createContext(std::unordered_map<std::string, Property> &values)
+{
+    ArchArgs chipArgs;
+    chipArgs.device = vm["device"].as<std::string>();
+    return std::unique_ptr<Context>(new Context(chipArgs));
+}
+
+void GowinCommandHandler::customAfterLoad(Context *ctx)
+{
+    // if (vm.count("pdc")) {
+    //     std::string filename = vm["pdc"].as<std::string>();
+    //     std::ifstream in(filename);
+    //     if (!in)
+    //         log_error("Failed to open input PDC file %s.\n", filename.c_str());
+    //     ctx->read_pdc(in);
+    // }
+}
+
+int main(int argc, char *argv[])
+{
+    GowinCommandHandler handler(argc, argv);
+    return handler.exec();
+}
+#endif
diff --git a/gowin/pack.cc b/gowin/pack.cc
new file mode 100644
index 00000000..43157b6c
--- /dev/null
+++ b/gowin/pack.cc
@@ -0,0 +1,288 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2018-19  David Shah <david@symbioticeda.com>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include <algorithm>
+#include <iterator>
+#include <unordered_set>
+#include "cells.h"
+#include "design_utils.h"
+#include "log.h"
+#include "util.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+
+// Pack LUTs and LUT-FF pairs
+static void pack_lut_lutffs(Context *ctx)
+{
+    log_info("Packing LUT-FFs..\n");
+
+    std::unordered_set<IdString> packed_cells;
+    std::vector<std::unique_ptr<CellInfo>> new_cells;
+    for (auto cell : sorted(ctx->cells)) {
+        CellInfo *ci = cell.second;
+        if (ctx->verbose)
+            log_info("cell '%s' is of type '%s'\n", ci->name.c_str(ctx), ci->type.c_str(ctx));
+        if (is_lut(ctx, ci)) {
+            std::unique_ptr<CellInfo> packed =
+                    create_generic_cell(ctx, ctx->id("GENERIC_SLICE"), ci->name.str(ctx) + "_LC");
+            std::copy(ci->attrs.begin(), ci->attrs.end(), std::inserter(packed->attrs, packed->attrs.begin()));
+            packed_cells.insert(ci->name);
+            if (ctx->verbose)
+                log_info("packed cell %s into %s\n", ci->name.c_str(ctx), packed->name.c_str(ctx));
+            // See if we can pack into a DFF
+            // TODO: LUT cascade
+            NetInfo *o = ci->ports.at(ctx->id("Q")).net;
+            CellInfo *dff = net_only_drives(ctx, o, is_ff, ctx->id("D"), true);
+            auto lut_bel = ci->attrs.find(ctx->id("BEL"));
+            bool packed_dff = false;
+            if (dff) {
+                if (ctx->verbose)
+                    log_info("found attached dff %s\n", dff->name.c_str(ctx));
+                auto dff_bel = dff->attrs.find(ctx->id("BEL"));
+                if (lut_bel != ci->attrs.end() && dff_bel != dff->attrs.end() && lut_bel->second != dff_bel->second) {
+                    // Locations don't match, can't pack
+                } else {
+                    lut_to_lc(ctx, ci, packed.get(), false);
+                    dff_to_lc(ctx, dff, packed.get(), false);
+                    ctx->nets.erase(o->name);
+                    if (dff_bel != dff->attrs.end())
+                        packed->attrs[ctx->id("BEL")] = dff_bel->second;
+                    packed_cells.insert(dff->name);
+                    if (ctx->verbose)
+                        log_info("packed cell %s into %s\n", dff->name.c_str(ctx), packed->name.c_str(ctx));
+                    packed_dff = true;
+                }
+            }
+            if (!packed_dff) {
+                lut_to_lc(ctx, ci, packed.get(), true);
+            }
+            new_cells.push_back(std::move(packed));
+        }
+    }
+    for (auto pcell : packed_cells) {
+        ctx->cells.erase(pcell);
+    }
+    for (auto &ncell : new_cells) {
+        ctx->cells[ncell->name] = std::move(ncell);
+    }
+}
+
+// Pack FFs not packed as LUTFFs
+static void pack_nonlut_ffs(Context *ctx)
+{
+    log_info("Packing non-LUT FFs..\n");
+
+    std::unordered_set<IdString> packed_cells;
+    std::vector<std::unique_ptr<CellInfo>> new_cells;
+
+    for (auto cell : sorted(ctx->cells)) {
+        CellInfo *ci = cell.second;
+        if (is_ff(ctx, ci)) {
+            std::unique_ptr<CellInfo> packed =
+                    create_generic_cell(ctx, ctx->id("GENERIC_SLICE"), ci->name.str(ctx) + "_DFFLC");
+            std::copy(ci->attrs.begin(), ci->attrs.end(), std::inserter(packed->attrs, packed->attrs.begin()));
+            if (ctx->verbose)
+                log_info("packed cell %s into %s\n", ci->name.c_str(ctx), packed->name.c_str(ctx));
+            packed_cells.insert(ci->name);
+            dff_to_lc(ctx, ci, packed.get(), true);
+            new_cells.push_back(std::move(packed));
+        }
+    }
+    for (auto pcell : packed_cells) {
+        ctx->cells.erase(pcell);
+    }
+    for (auto &ncell : new_cells) {
+        ctx->cells[ncell->name] = std::move(ncell);
+    }
+}
+
+// Merge a net into a constant net
+static void set_net_constant(const Context *ctx, NetInfo *orig, NetInfo *constnet, bool constval)
+{
+    orig->driver.cell = nullptr;
+    for (auto user : orig->users) {
+        if (user.cell != nullptr) {
+            CellInfo *uc = user.cell;
+            if (ctx->verbose)
+                log_info("%s user %s\n", orig->name.c_str(ctx), uc->name.c_str(ctx));
+            if ((is_lut(ctx, uc) || is_lc(ctx, uc)) && (user.port.str(ctx).at(0) == 'I') && !constval) {
+                uc->ports[user.port].net = nullptr;
+            } else {
+                uc->ports[user.port].net = constnet;
+                constnet->users.push_back(user);
+            }
+        }
+    }
+    orig->users.clear();
+}
+
+// Pack constants (simple implementation)
+static void pack_constants(Context *ctx)
+{
+    log_info("Packing constants..\n");
+
+    std::unique_ptr<CellInfo> gnd_cell = create_generic_cell(ctx, ctx->id("GENERIC_SLICE"), "$PACKER_GND");
+    gnd_cell->params[ctx->id("INIT")] = Property(0, 1 << ctx->args.K);
+    std::unique_ptr<NetInfo> gnd_net = std::unique_ptr<NetInfo>(new NetInfo);
+    gnd_net->name = ctx->id("$PACKER_GND_NET");
+    gnd_net->driver.cell = gnd_cell.get();
+    gnd_net->driver.port = ctx->id("F");
+    gnd_cell->ports.at(ctx->id("F")).net = gnd_net.get();
+
+    std::unique_ptr<CellInfo> vcc_cell = create_generic_cell(ctx, ctx->id("GENERIC_SLICE"), "$PACKER_VCC");
+    // Fill with 1s
+    vcc_cell->params[ctx->id("INIT")] = Property(Property::S1).extract(0, (1 << ctx->args.K), Property::S1);
+    std::unique_ptr<NetInfo> vcc_net = std::unique_ptr<NetInfo>(new NetInfo);
+    vcc_net->name = ctx->id("$PACKER_VCC_NET");
+    vcc_net->driver.cell = vcc_cell.get();
+    vcc_net->driver.port = ctx->id("F");
+    vcc_cell->ports.at(ctx->id("F")).net = vcc_net.get();
+
+    std::vector<IdString> dead_nets;
+
+    bool gnd_used = false;
+
+    for (auto net : sorted(ctx->nets)) {
+        NetInfo *ni = net.second;
+        if (ni->driver.cell != nullptr && ni->driver.cell->type == ctx->id("GND")) {
+            IdString drv_cell = ni->driver.cell->name;
+            set_net_constant(ctx, ni, gnd_net.get(), false);
+            gnd_used = true;
+            dead_nets.push_back(net.first);
+            ctx->cells.erase(drv_cell);
+        } else if (ni->driver.cell != nullptr && ni->driver.cell->type == ctx->id("VCC")) {
+            IdString drv_cell = ni->driver.cell->name;
+            set_net_constant(ctx, ni, vcc_net.get(), true);
+            dead_nets.push_back(net.first);
+            ctx->cells.erase(drv_cell);
+        }
+    }
+
+    if (gnd_used) {
+        ctx->cells[gnd_cell->name] = std::move(gnd_cell);
+        ctx->nets[gnd_net->name] = std::move(gnd_net);
+    }
+    // Vcc cell always inserted for now, as it may be needed during carry legalisation (TODO: trim later if actually
+    // never used?)
+    ctx->cells[vcc_cell->name] = std::move(vcc_cell);
+    ctx->nets[vcc_net->name] = std::move(vcc_net);
+
+    for (auto dn : dead_nets) {
+        ctx->nets.erase(dn);
+    }
+}
+
+static bool is_nextpnr_iob(Context *ctx, CellInfo *cell)
+{
+    return cell->type == ctx->id("$nextpnr_ibuf") || cell->type == ctx->id("$nextpnr_obuf") ||
+           cell->type == ctx->id("$nextpnr_iobuf");
+}
+
+static bool is_generic_iob(const Context *ctx, const CellInfo *cell) { return cell->type == ctx->id("GENERIC_IOB"); }
+
+// Pack IO buffers
+static void pack_io(Context *ctx)
+{
+    std::unordered_set<IdString> packed_cells;
+    std::unordered_set<IdString> delete_nets;
+
+    std::vector<std::unique_ptr<CellInfo>> new_cells;
+    log_info("Packing IOs..\n");
+
+    for (auto cell : sorted(ctx->cells)) {
+        CellInfo *ci = cell.second;
+        if (is_nextpnr_iob(ctx, ci)) {
+            CellInfo *iob = nullptr;
+            if (ci->type == ctx->id("$nextpnr_ibuf") || ci->type == ctx->id("$nextpnr_iobuf")) {
+                iob = net_only_drives(ctx, ci->ports.at(ctx->id("O")).net, is_generic_iob, ctx->id("PAD"), true, ci);
+
+            } else if (ci->type == ctx->id("$nextpnr_obuf")) {
+                NetInfo *net = ci->ports.at(ctx->id("I")).net;
+                iob = net_only_drives(ctx, net, is_generic_iob, ctx->id("PAD"), true, ci);
+            }
+            if (iob != nullptr) {
+                // Trivial case, GENERIC_IOB used. Just destroy the net and the
+                // iobuf
+                log_info("%s feeds GENERIC_IOB %s, removing %s %s.\n", ci->name.c_str(ctx), iob->name.c_str(ctx),
+                         ci->type.c_str(ctx), ci->name.c_str(ctx));
+                NetInfo *net = iob->ports.at(ctx->id("PAD")).net;
+                if (((ci->type == ctx->id("$nextpnr_ibuf") || ci->type == ctx->id("$nextpnr_iobuf")) &&
+                     net->users.size() > 1) ||
+                    (ci->type == ctx->id("$nextpnr_obuf") && (net->users.size() > 2 || net->driver.cell != nullptr)))
+                    log_error("PAD of %s '%s' connected to more than a single top level IO.\n", iob->type.c_str(ctx),
+                              iob->name.c_str(ctx));
+
+                if (net != nullptr) {
+                    delete_nets.insert(net->name);
+                    iob->ports.at(ctx->id("PAD")).net = nullptr;
+                }
+                if (ci->type == ctx->id("$nextpnr_iobuf")) {
+                    NetInfo *net2 = ci->ports.at(ctx->id("I")).net;
+                    if (net2 != nullptr) {
+                        delete_nets.insert(net2->name);
+                    }
+                }
+            } else if (bool_or_default(ctx->settings, ctx->id("disable_iobs"))) {
+                // No IO buffer insertion; just remove nextpnr_[io]buf
+                for (auto &p : ci->ports)
+                    disconnect_port(ctx, ci, p.first);
+            } else {
+                // Create a GENERIC_IOB buffer
+                std::unique_ptr<CellInfo> ice_cell =
+                        create_generic_cell(ctx, ctx->id("GENERIC_IOB"), ci->name.str(ctx) + "$iob");
+                nxio_to_iob(ctx, ci, ice_cell.get(), packed_cells);
+                new_cells.push_back(std::move(ice_cell));
+                iob = new_cells.back().get();
+            }
+            packed_cells.insert(ci->name);
+            if (iob != nullptr)
+                std::copy(ci->attrs.begin(), ci->attrs.end(), std::inserter(iob->attrs, iob->attrs.begin()));
+        }
+    }
+    for (auto pcell : packed_cells) {
+        ctx->cells.erase(pcell);
+    }
+    for (auto dnet : delete_nets) {
+        ctx->nets.erase(dnet);
+    }
+    for (auto &ncell : new_cells) {
+        ctx->cells[ncell->name] = std::move(ncell);
+    }
+}
+
+// Main pack function
+bool Arch::pack()
+{
+    Context *ctx = getCtx();
+    try {
+        log_break();
+        pack_constants(ctx);
+        pack_io(ctx);
+        pack_lut_lutffs(ctx);
+        pack_nonlut_ffs(ctx);
+        ctx->settings[ctx->id("pack")] = 1;
+        ctx->assignArchInfo();
+        log_info("Checksum: 0x%08x\n", ctx->checksum());
+        return true;
+    } catch (log_execution_error_exception) {
+        return false;
+    }
+}
+
+NEXTPNR_NAMESPACE_END