Merge pull request #261 from YosysHQ/pygeneric

Python API for generic architecture

21 files changed, 1187 insertions, 17 deletions

diff --git a/generic/arch.cc b/generic/arch.cc
index aca81559..5617fa63 100644
--- a/generic/arch.cc
+++ b/generic/arch.cc
@@ -17,6 +17,7 @@
  *
  */
 
+#include <iostream>
 #include <math.h>
 #include "nextpnr.h"
 #include "placer1.h"
@@ -191,9 +192,53 @@ void Arch::setPipAttr(IdString pip, IdString key, const std::string &value) { pi
 
 void Arch::setBelAttr(IdString bel, IdString key, const std::string &value) { bels.at(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;
+}
+
 // ---------------------------------------------------------------
 
-Arch::Arch(ArchArgs args) : chipName("generic"), args(args) {}
+Arch::Arch(ArchArgs args) : chipName("generic"), args(args)
+{
+    // Dummy for empty decals
+    decal_graphics[IdString()];
+}
 
 void IdString::initialize_arch(const BaseCtx *ctx) {}
 
@@ -260,7 +305,13 @@ 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 { return bels.at(bel).pins.at(pin).wire; }
+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; }
 
@@ -422,7 +473,7 @@ delay_t Arch::estimateDelay(WireId src, WireId dst) const
     const WireInfo &d = wires.at(dst);
     int dx = abs(s.x - d.x);
     int dy = abs(s.y - d.y);
-    return (dx + dy) * grid_distance_to_delay;
+    return (dx + dy) * args.delayScale + args.delayOffset;
 }
 
 delay_t Arch::predictDelay(const NetInfo *net_info, const PortRef &sink) const
@@ -431,9 +482,9 @@ delay_t Arch::predictDelay(const NetInfo *net_info, const PortRef &sink) const
     auto driver_loc = getBelLocation(driver.cell->bel);
     auto sink_loc = getBelLocation(sink.cell->bel);
 
-    int dx = abs(driver_loc.x - driver_loc.x);
-    int dy = abs(sink_loc.y - sink_loc.y);
-    return (dx + dy) * grid_distance_to_delay;
+    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; }
@@ -455,7 +506,14 @@ bool Arch::route() { return router1(getCtx(), Router1Cfg(getCtx())); }
 
 // ---------------------------------------------------------------
 
-const std::vector<GraphicElement> &Arch::getDecalGraphics(DecalId decal) const { return decal_graphics.at(decal); }
+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; }
 
@@ -469,24 +527,103 @@ DecalXY Arch::getGroupDecal(GroupId group) const { return groups.at(group).decal
 
 bool Arch::getCellDelay(const CellInfo *cell, IdString fromPort, IdString toPort, DelayInfo &delay) const
 {
-    return false;
+    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
 {
-    return TMG_IGNORE;
+    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_FALSE("no clocking info for generic");
+    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::isValidBelForCell(CellInfo *cell, BelId bel) const { return true; }
-bool Arch::isBelLocationValid(BelId bel) const { return true; }
+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()));
+}
 
 const std::string Arch::defaultPlacer = "sa";
 const std::vector<std::string> Arch::availablePlacers = {"sa"};
 
+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/generic/arch.h b/generic/arch.h
index 5b5d8c55..e9d3593c 100644
--- a/generic/arch.h
+++ b/generic/arch.h
@@ -25,6 +25,11 @@ NEXTPNR_NAMESPACE_BEGIN
 
 struct ArchArgs
 {
+    // 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;
@@ -81,6 +86,33 @@ struct GroupInfo
     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 chipName;
@@ -101,7 +133,7 @@ struct Arch : BaseCtx
     std::vector<std::vector<int>> tileBelDimZ;
     std::vector<std::vector<int>> tilePipDimZ;
 
-    float grid_distance_to_delay;
+    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);
@@ -127,6 +159,14 @@ struct Arch : BaseCtx
     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);
+
     // ---------------------------------------------------------------
     // Common Arch API. Every arch must provide the following methods.
 
@@ -208,8 +248,8 @@ struct Arch : BaseCtx
 
     delay_t estimateDelay(WireId src, WireId dst) const;
     delay_t predictDelay(const NetInfo *net_info, const PortRef &sink) const;
-    delay_t getDelayEpsilon() const { return 0.01; }
-    delay_t getRipupDelayPenalty() const { return 1.0; }
+    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
@@ -222,7 +262,7 @@ struct Arch : BaseCtx
     uint32_t getDelayChecksum(delay_t v) const { return 0; }
     bool getBudgetOverride(const NetInfo *net_info, const PortRef &sink, delay_t &budget) const;
 
-    bool pack() { return true; }
+    bool pack();
     bool place();
     bool route();
 
@@ -243,6 +283,11 @@ struct Arch : BaseCtx
 
     static const std::string defaultPlacer;
     static const std::vector<std::string> availablePlacers;
+
+    // ---------------------------------------------------------------
+    // Internal usage
+    void assignArchInfo();
+    bool cellsCompatible(const CellInfo **cells, int count) const;
 };
 
 NEXTPNR_NAMESPACE_END
diff --git a/generic/arch_pybindings.cc b/generic/arch_pybindings.cc
index 186b2c13..8526e409 100644
--- a/generic/arch_pybindings.cc
+++ b/generic/arch_pybindings.cc
@@ -23,18 +23,215 @@
 #include "arch_pybindings.h"
 #include "nextpnr.h"
 #include "pybindings.h"
+#include "pywrappers.h"
 
 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()
 {
     using namespace PythonConversion;
+
     auto arch_cls = class_<Arch, Arch *, bases<BaseCtx>, boost::noncopyable>("Arch", init<ArchArgs>());
+
+    auto dxy_cls = class_<ContextualWrapper<DecalXY>>("DecalXY_", no_init);
+    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 = class_<Context, Context *, bases<Arch>, boost::noncopyable>("Context", no_init)
                            .def("checksum", &Context::checksum)
                            .def("pack", &Context::pack)
                            .def("place", &Context::place)
                            .def("route", &Context::route);
+
+    class_<BelPin>("BelPin").def_readwrite("bel", &BelPin::bel).def_readwrite("pin", &BelPin::pin);
+
+    class_<DelayInfo>("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::getWireAliases), &Context::getWireAliases,
+                  wrap_context<const std::vector<PipId> &>, conv_from_str<WireId>>::def_wrap(ctx_cls, "getWireAliases");
+
+    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;
+
+    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",
+                                                                                             (arg("name"), "type", "x",
+                                                                                              "y"));
+    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",
+                                                 (arg("name"), "type", "srcWire", "dstWire", "delay", "loc"));
+    fn_wrapper_5a_v<Context, decltype(&Context::addAlias), &Context::addAlias, conv_from_str<IdString>,
+                    conv_from_str<IdString>, conv_from_str<IdString>, conv_from_str<IdString>,
+                    pass_through<DelayInfo>>::def_wrap(ctx_cls, "addAlias",
+                                                       (arg("name"), "type", "srcWire", "dstWire", "delay"));
+
+    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",
+                                                                                              (arg("name"), "type",
+                                                                                               "loc", "gb"));
+    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",
+                                                                                (arg("bel"), "name", "wire"));
+    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",
+                                                                                (arg("bel"), "name", "wire"));
+    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",
+                                                                                (arg("bel"), "name", "wire"));
+
+    fn_wrapper_2a_v<Context, decltype(&Context::addGroupBel), &Context::addGroupBel, conv_from_str<IdString>,
+                    conv_from_str<IdString>>::def_wrap(ctx_cls, "addGroupBel", (arg("group"), "bel"));
+    fn_wrapper_2a_v<Context, decltype(&Context::addGroupWire), &Context::addGroupWire, conv_from_str<IdString>,
+                    conv_from_str<IdString>>::def_wrap(ctx_cls, "addGroupWire", (arg("group"), "wire"));
+    fn_wrapper_2a_v<Context, decltype(&Context::addGroupPip), &Context::addGroupPip, conv_from_str<IdString>,
+                    conv_from_str<IdString>>::def_wrap(ctx_cls, "addGroupPip", (arg("group"), "pip"));
+    fn_wrapper_2a_v<Context, decltype(&Context::addGroupGroup), &Context::addGroupPip, conv_from_str<IdString>,
+                    conv_from_str<IdString>>::def_wrap(ctx_cls, "addGroupGroup", (arg("group"), "grp"));
+
+    fn_wrapper_2a_v<Context, decltype(&Context::addDecalGraphic), &Context::addDecalGraphic, conv_from_str<DecalId>,
+                    pass_through<GraphicElement>>::def_wrap(ctx_cls, "addDecalGraphic", (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", (arg("wire"), "decalxy"));
+    fn_wrapper_2a_v<Context, decltype(&Context::setPipDecal), &Context::setPipDecal, conv_from_str<DecalId>,
+                    unwrap_context<DecalXY>>::def_wrap(ctx_cls, "setPipDecal", (arg("pip"), "decalxy"));
+    fn_wrapper_2a_v<Context, decltype(&Context::setBelDecal), &Context::setBelDecal, conv_from_str<DecalId>,
+                    unwrap_context<DecalXY>>::def_wrap(ctx_cls, "setBelDecal", (arg("bel"), "decalxy"));
+    fn_wrapper_2a_v<Context, decltype(&Context::setGroupDecal), &Context::setGroupDecal, conv_from_str<DecalId>,
+                    unwrap_context<DecalXY>>::def_wrap(ctx_cls, "setGroupDecal", (arg("group"), "decalxy"));
+
+    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",
+                                                                                  (arg("wire"), "key", "value"));
+    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",
+                                                                                  (arg("bel"), "key", "value"));
+    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",
+                                                                                  (arg("pip"), "key", "value"));
+
+    fn_wrapper_1a_v<Context, decltype(&Context::setLutK), &Context::setLutK, pass_through<int>>::def_wrap(
+            ctx_cls, "setLutK", arg("K"));
+    fn_wrapper_2a_v<Context, decltype(&Context::setDelayScaling), &Context::setDelayScaling, pass_through<double>,
+                    pass_through<double>>::def_wrap(ctx_cls, "setDelayScaling", (arg("scale"), "offset"));
+
+    fn_wrapper_2a_v<Context, decltype(&Context::addCellTimingClock), &Context::addCellTimingClock,
+                    conv_from_str<IdString>, conv_from_str<IdString>>::def_wrap(ctx_cls, "addCellTimingClock",
+                                                                                (arg("cell"), "port"));
+    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",
+                                                       (arg("cell"), "fromPort", "toPort", "delay"));
+    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",
+                                                       (arg("cell"), "port", "clock", "setup", "hold"));
+    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",
+                                                       (arg("cell"), "port", "clock", "clktoq"));
+
+    WRAP_MAP_UPTR(CellMap, "IdCellMap");
+    WRAP_MAP_UPTR(NetMap, "IdNetMap");
+    WRAP_VECTOR(const std::vector<IdString>, conv_to_str<IdString>);
 }
 
 NEXTPNR_NAMESPACE_END
diff --git a/generic/archdefs.h b/generic/archdefs.h
index 2452aa17..978c9c9b 100644
--- a/generic/archdefs.h
+++ b/generic/archdefs.h
@@ -55,8 +55,18 @@ 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/generic/cells.cc b/generic/cells.cc
new file mode 100644
index 00000000..14b368b2
--- /dev/null
+++ b/generic/cells.cc
@@ -0,0 +1,139 @@
+/*
+ *  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")] = std::to_string(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(), "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) {
+        replace_port(lut, ctx->id("Q"), lc, ctx->id("Q"));
+        lc->params[ctx->id("FF_USED")] = "0";
+    }
+}
+
+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) {
+        lc->params[ctx->id("INIT")] = "2";
+        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/generic/cells.h b/generic/cells.h
new file mode 100644
index 00000000..646d738d
--- /dev/null
+++ b/generic/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/generic/examples/.gitignore b/generic/examples/.gitignore
new file mode 100644
index 00000000..38e95de5
--- /dev/null
+++ b/generic/examples/.gitignore
@@ -0,0 +1,3 @@
+blinky.fasm
+__pycache__
+*.pyc
diff --git a/generic/examples/README.md b/generic/examples/README.md
new file mode 100644
index 00000000..9fd106d9
--- /dev/null
+++ b/generic/examples/README.md
@@ -0,0 +1,14 @@
+# Generic Architecture Example
+
+This contains a simple, artificial, example of the nextpnr generic API.
+
+ - simple.py procedurally generates a simple FPGA architecture with IO at the edges,
+   logic slices in all other tiles, and interconnect only between adjacent tiles
+ 
+ - simple_timing.py annotates cells with timing data (this is a separate script that must be run after packing)
+
+ - write_fasm.py uses the nextpnr Python API to write a FASM file for a design
+
+ - bitstream.py uses write_fasm.py to create a FASM ("FPGA assembly") file for the place-and-routed design
+
+ - Run simple.sh to build an example design on the FPGA above
\ No newline at end of file
diff --git a/generic/examples/__init__.py b/generic/examples/__init__.py
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/generic/examples/__init__.py
diff --git a/generic/examples/bitstream.py b/generic/examples/bitstream.py
new file mode 100644
index 00000000..1ab94f0c
--- /dev/null
+++ b/generic/examples/bitstream.py
@@ -0,0 +1,17 @@
+from write_fasm import *
+from simple_config import K
+
+# Need to tell FASM generator how to write parameters
+# (celltype, parameter) -> ParameterConfig
+param_map = {
+	("GENERIC_SLICE", "K"): ParameterConfig(write=False),
+	("GENERIC_SLICE", "INIT"): ParameterConfig(write=True, numeric=True, width=2**K),
+	("GENERIC_SLICE", "FF_USED"): ParameterConfig(write=True, numeric=True, width=1),
+
+	("GENERIC_IOB", "INPUT_USED"): ParameterConfig(write=True, numeric=True, width=1),
+	("GENERIC_IOB", "OUTPUT_USED"): ParameterConfig(write=True, numeric=True, width=1),
+	("GENERIC_IOB", "ENABLE_USED"): ParameterConfig(write=True, numeric=True, width=1),
+}
+
+with open("blinky.fasm", "w") as f:
+	write_fasm(ctx, param_map, f)
\ No newline at end of file
diff --git a/generic/examples/blinky.v b/generic/examples/blinky.v
new file mode 100644
index 00000000..b7cb1b86
--- /dev/null
+++ b/generic/examples/blinky.v
@@ -0,0 +1,9 @@
+module top(input clk, output reg [7:0] leds);
+
+reg [25:0] ctr;
+always @(posedge clk)
+	ctr <= ctr + 1'b1;
+
+assign leds = ctr[25:18];
+
+endmodule
\ No newline at end of file
diff --git a/generic/examples/simple.py b/generic/examples/simple.py
new file mode 100644
index 00000000..9339b68a
--- /dev/null
+++ b/generic/examples/simple.py
@@ -0,0 +1,72 @@
+from simple_config import *
+
+def is_io(x, y):
+	return x == 0 or x == X-1 or y == 0 or y == Y-1
+
+for x in range(X):
+	for y in range(Y):
+		# Bel port wires
+		for z in range(N):
+			ctx.addWire(name="X%dY%dZ%d_CLK" % (x, y, z), type="BEL_CLK", x=x, y=y)
+			ctx.addWire(name="X%dY%dZ%d_Q" % (x, y, z), type="BEL_Q", x=x, y=y)
+			for i in range(K):
+				ctx.addWire(name="X%dY%dZ%d_I%d" % (x, y, z, i), type="BEL_I", x=x, y=y)
+		# Local wires
+		for l in range(Wl):
+			ctx.addWire(name="X%dY%d_LOCAL%d" % (x, y, l), type="LOCAL", x=x, y=y)
+		# Create bels
+		if is_io(x, y):
+			if x == y:
+				continue
+			for z in range(2):
+				ctx.addBel(name="X%dY%d_IO%d" % (x, y, z), type="GENERIC_IOB", loc=Loc(x, y, z), gb=False)
+				ctx.addBelInput(bel="X%dY%d_IO%d" % (x, y, z), name="I", wire="X%dY%dZ%d_I0" % (x, y, z))
+				ctx.addBelInput(bel="X%dY%d_IO%d" % (x, y, z), name="EN", wire="X%dY%dZ%d_I1" % (x, y, z))
+				ctx.addBelOutput(bel="X%dY%d_IO%d" % (x, y, z), name="O", wire="X%dY%dZ%d_Q" % (x, y, z))
+		else:
+			for z in range(N):
+				ctx.addBel(name="X%dY%d_SLICE%d" % (x, y, z), type="GENERIC_SLICE", loc=Loc(x, y, z), gb=False)
+				ctx.addBelInput(bel="X%dY%d_SLICE%d" % (x, y, z), name="CLK", wire="X%dY%dZ%d_CLK" % (x, y, z))
+				for k in range(K):
+					ctx.addBelInput(bel="X%dY%d_SLICE%d" % (x, y, z), name="I[%d]" % k, wire="X%dY%dZ%d_I%d" % (x, y, z, k))
+				ctx.addBelOutput(bel="X%dY%d_SLICE%d" % (x, y, z), name="Q", wire="X%dY%dZ%d_Q" % (x, y, z))
+
+for x in range(X):
+	for y in range(Y):
+		# Pips driving bel input wires
+		# Bel input wires are driven by every Si'th local with an offset
+		def create_input_pips(dst, offset, skip):
+			for i in range(offset % skip, Wl, skip):
+				src = "X%dY%d_LOCAL%d" % (x, y, i)
+				ctx.addPip(name="X%dY%d.%s.%s" % (x, y, src, dst), type="BEL_INPUT",
+					srcWire=src, dstWire=dst, delay=ctx.getDelayFromNS(0.05), loc=Loc(x, y, 0))
+		for z in range(N):
+			create_input_pips("X%dY%dZ%d_CLK" % (x, y, z), 0, Si)
+			for k in range(K):
+				create_input_pips("X%dY%dZ%d_I%d" % (x, y, z, k), k % Si, Si)
+
+		# Pips from bel outputs to locals
+		def create_output_pips(dst, offset, skip):
+			for i in range(offset % skip, N, skip):
+				src = "X%dY%dZ%d_Q" % (x, y, i)
+				ctx.addPip(name="X%dY%d.%s.%s" % (x, y, src, dst), type="BEL_OUTPUT",
+					srcWire=src, dstWire=dst, delay=ctx.getDelayFromNS(0.05), loc=Loc(x, y, 0))
+		# Pips from neighbour locals to locals
+		def create_neighbour_pips(dst, nx, ny, offset, skip):
+			if nx < 0 or nx >= X or ny < 0 or ny >= Y:
+				return
+			for i in range(offset % skip, Wl, skip):
+				src = "X%dY%d_LOCAL%d" % (nx, ny, i)
+				ctx.addPip(name="X%dY%d.%s.%s" % (x, y, src, dst), type="NEIGHBOUR",
+					srcWire=src, dstWire=dst, delay=ctx.getDelayFromNS(0.05), loc=Loc(x, y, 0))
+		for l in range(Wl):
+			dst = "X%dY%d_LOCAL%d" % (x, y, l)
+			create_output_pips(dst, l % Sq, Sq)
+			create_neighbour_pips(dst, x-1, y-1, (l + 1) % Sl, Sl)
+			create_neighbour_pips(dst, x-1, y, (l + 2) % Sl, Sl)
+			create_neighbour_pips(dst, x-1, y+1, (l + 2) % Sl, Sl)
+			create_neighbour_pips(dst, x, y-1, (l + 3) % Sl, Sl)
+			create_neighbour_pips(dst, x, y+1, (l + 4) % Sl, Sl)
+			create_neighbour_pips(dst, x+1, y-1, (l + 5) % Sl, Sl)
+			create_neighbour_pips(dst, x+1, y, (l + 6) % Sl, Sl)
+			create_neighbour_pips(dst, x+1, y+1, (l + 7) % Sl, Sl)
\ No newline at end of file
diff --git a/generic/examples/simple.sh b/generic/examples/simple.sh
new file mode 100755
index 00000000..8ae903f9
--- /dev/null
+++ b/generic/examples/simple.sh
@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+set -ex
+yosys -p "tcl ../synth/synth_generic.tcl 4 blinky.json" blinky.v
+${NEXTPNR:-../../nextpnr-generic} --pre-pack simple.py --pre-place simple_timing.py --json blinky.json --post-route bitstream.py
diff --git a/generic/examples/simple_config.py b/generic/examples/simple_config.py
new file mode 100644
index 00000000..dfb38f1c
--- /dev/null
+++ b/generic/examples/simple_config.py
@@ -0,0 +1,15 @@
+# Grid size including IOBs at edges
+X = 12
+Y = 12
+# SLICEs per tile
+N = 8
+# LUT input count
+K = 4
+# Number of local wires
+Wl = N*(K+1) + 8 
+# 1/Fc for bel input wire pips
+Si = 4
+# 1/Fc for Q to local wire pips
+Sq = 4
+# ~1/Fc local to neighbour local wire pips
+Sl = 8
\ No newline at end of file
diff --git a/generic/examples/simple_timing.py b/generic/examples/simple_timing.py
new file mode 100644
index 00000000..a955c8d7
--- /dev/null
+++ b/generic/examples/simple_timing.py
@@ -0,0 +1,15 @@
+for cname, cell in ctx.cells:
+	if cell.type != "GENERIC_SLICE":
+		continue
+	if cname in ("$PACKER_GND", "$PACKER_VCC"):
+		continue
+	K = int(cell.params["K"])
+	if cell.params["FF_USED"] == "1":
+		ctx.addCellTimingClock(cell=cname, port="CLK")
+		for i in range(K):
+			ctx.addCellTimingSetupHold(cell=cname, port="I[%d]" % i, clock="CLK",
+				setup=ctx.getDelayFromNS(0.2), hold=ctx.getDelayFromNS(0))
+		ctx.addCellTimingClockToOut(cell=cname, port="Q", clock="CLK", clktoq=ctx.getDelayFromNS(0.2))
+	else:
+		for i in range(K):
+			ctx.addCellTimingDelay(cell=cname, fromPort="I[%d]" % i, toPort="Q", delay=ctx.getDelayFromNS(0.2))
\ No newline at end of file
diff --git a/generic/examples/write_fasm.py b/generic/examples/write_fasm.py
new file mode 100644
index 00000000..1f279b63
--- /dev/null
+++ b/generic/examples/write_fasm.py
@@ -0,0 +1,52 @@
+from collections import namedtuple
+
+"""
+	write:   set to True to enable writing this parameter to FASM
+
+	numeric: set to True to write this parameter as a bit array (width>1) or
+	         single bit (width==1) named after the parameter. Otherwise this
+	         parameter will be written as `name.value`
+
+	width:   width of numeric parameter (ignored for non-numeric parameters)
+	
+	alias:   an alternative name for this parameter (parameter name used if alias
+	         is None)
+"""
+ParameterConfig = namedtuple('ParameterConfig', 'write numeric width alias')
+
+# FIXME use defaults= once Python 3.7 is standard
+ParameterConfig.__new__.__defaults__ = (False, True, 1, None)
+
+
+"""
+Write a design as FASM
+
+    ctx:      nextpnr context
+    paramCfg: map from (celltype, parametername) -> ParameterConfig describing how to write parameters
+    f:        output file
+"""
+def write_fasm(ctx, paramCfg, f):
+	for nname, net in sorted(ctx.nets, key=lambda x: str(x[1].name)):
+		print("# Net %s" % nname, file=f)
+		for wire, pip in sorted(net.wires, key=lambda x: str(x[1])):
+			if pip.pip != "":
+				print("%s" % pip.pip, file=f)
+		print("", file=f)
+	for cname, cell in sorted(ctx.cells, key=lambda x: str(x[1].name)):
+		print("# Cell %s at %s" % (cname, cell.bel), file=f)
+		for param, val in sorted(cell.params, key=lambda x: str(x)):
+			cfg = paramCfg[(cell.type, param)]
+			if not cfg.write:
+				continue
+			fasm_name = cfg.alias if cfg.alias is not None else param
+			if cfg.numeric:
+				if cfg.width == 1:
+					if int(val) != 0:
+						print("%s.%s" % (cell.bel, fasm_name), file=f)
+				else:
+					# Parameters with width >32 are direct binary, otherwise denary
+					binval = val if cfg.width > 32 else "{:0{}b}".format(int(val), cfg.width)
+					print("%s.%s[%d:0] = %d'b%s" % (cell.bel, fasm_name, cfg.width-1, cfg.width, binval), file=f)
+			else:
+				print("%s.%s.%s" % (cell.bel, fasm_name, val), file=f)
+		print("", file=f)
\ No newline at end of file
diff --git a/generic/main.cc b/generic/main.cc
index 08b0b348..c203f35c 100644
--- a/generic/main.cc
+++ b/generic/main.cc
@@ -49,7 +49,7 @@ po::options_description GenericCommandHandler::getArchOptions()
     return specific;
 }
 
-void GenericCommandHandler::customBitstream(Context *ctx) { log_error("Here is when bitstream gets created"); }
+void GenericCommandHandler::customBitstream(Context *ctx) {}
 
 std::unique_ptr<Context> GenericCommandHandler::createContext()
 {
diff --git a/generic/pack.cc b/generic/pack.cc
new file mode 100644
index 00000000..26ae9182
--- /dev/null
+++ b/generic/pack.cc
@@ -0,0 +1,293 @@
+/*
+ *  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);
+    }
+}
+
+static bool net_is_constant(const Context *ctx, NetInfo *net, bool &value)
+{
+    if (net == nullptr)
+        return false;
+    if (net->name == ctx->id("$PACKER_GND_NET") || net->name == ctx->id("$PACKER_VCC_NET")) {
+        value = (net->name == ctx->id("$PACKER_VCC_NET"));
+        return true;
+    } else {
+        return false;
+    }
+}
+
+// Merge a net into a constant net
+static void set_net_constant(const Context *ctx, NetInfo *orig, NetInfo *constnet, bool constval)
+{
+    orig->driver.cell = nullptr;
+    for (auto user : orig->users) {
+        if (user.cell != nullptr) {
+            CellInfo *uc = user.cell;
+            if (ctx->verbose)
+                log_info("%s user %s\n", orig->name.c_str(ctx), uc->name.c_str(ctx));
+            if ((is_lut(ctx, uc) || is_lc(ctx, uc)) && (user.port.str(ctx).at(0) == 'I') && !constval) {
+                uc->ports[user.port].net = nullptr;
+            } else {
+                uc->ports[user.port].net = constnet;
+                constnet->users.push_back(user);
+            }
+        }
+    }
+    orig->users.clear();
+}
+
+// Pack constants (simple implementation)
+static void pack_constants(Context *ctx)
+{
+    log_info("Packing constants..\n");
+
+    std::unique_ptr<CellInfo> gnd_cell = create_generic_cell(ctx, ctx->id("GENERIC_SLICE"), "$PACKER_GND");
+    gnd_cell->params[ctx->id("INIT")] = "0";
+    std::unique_ptr<NetInfo> gnd_net = std::unique_ptr<NetInfo>(new NetInfo);
+    gnd_net->name = ctx->id("$PACKER_GND_NET");
+    gnd_net->driver.cell = gnd_cell.get();
+    gnd_net->driver.port = ctx->id("Q");
+    gnd_cell->ports.at(ctx->id("Q")).net = gnd_net.get();
+
+    std::unique_ptr<CellInfo> vcc_cell = create_generic_cell(ctx, ctx->id("GENERIC_SLICE"), "$PACKER_VCC");
+    vcc_cell->params[ctx->id("INIT")] = "1";
+    std::unique_ptr<NetInfo> vcc_net = std::unique_ptr<NetInfo>(new NetInfo);
+    vcc_net->name = ctx->id("$PACKER_VCC_NET");
+    vcc_net->driver.cell = vcc_cell.get();
+    vcc_net->driver.port = ctx->id("Q");
+    vcc_cell->ports.at(ctx->id("Q")).net = vcc_net.get();
+
+    std::vector<IdString> dead_nets;
+
+    bool gnd_used = false;
+
+    for (auto net : sorted(ctx->nets)) {
+        NetInfo *ni = net.second;
+        if (ni->driver.cell != nullptr && ni->driver.cell->type == ctx->id("GND")) {
+            IdString drv_cell = ni->driver.cell->name;
+            set_net_constant(ctx, ni, gnd_net.get(), false);
+            gnd_used = true;
+            dead_nets.push_back(net.first);
+            ctx->cells.erase(drv_cell);
+        } else if (ni->driver.cell != nullptr && ni->driver.cell->type == ctx->id("VCC")) {
+            IdString drv_cell = ni->driver.cell->name;
+            set_net_constant(ctx, ni, vcc_net.get(), true);
+            dead_nets.push_back(net.first);
+            ctx->cells.erase(drv_cell);
+        }
+    }
+
+    if (gnd_used) {
+        ctx->cells[gnd_cell->name] = std::move(gnd_cell);
+        ctx->nets[gnd_net->name] = std::move(gnd_net);
+    }
+    // Vcc cell always inserted for now, as it may be needed during carry legalisation (TODO: trim later if actually
+    // never used?)
+    ctx->cells[vcc_cell->name] = std::move(vcc_cell);
+    ctx->nets[vcc_net->name] = std::move(vcc_net);
+
+    for (auto dn : dead_nets) {
+        ctx->nets.erase(dn);
+    }
+}
+
+static bool is_nextpnr_iob(Context *ctx, CellInfo *cell)
+{
+    return cell->type == ctx->id("$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("$nextpnr_iobuf")) {
+                    NetInfo *net2 = ci->ports.at(ctx->id("I")).net;
+                    if (net2 != nullptr) {
+                        delete_nets.insert(net2->name);
+                    }
+                }
+            } else {
+                // Create a GENERIC_IOB buffer
+                std::unique_ptr<CellInfo> ice_cell =
+                        create_generic_cell(ctx, ctx->id("GENERIC_IOB"), ci->name.str(ctx) + "$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);
+            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->assignArchInfo();
+        log_info("Checksum: 0x%08x\n", ctx->checksum());
+        return true;
+    } catch (log_execution_error_exception) {
+        return false;
+    }
+}
+
+NEXTPNR_NAMESPACE_END
diff --git a/generic/synth/cells_map.v b/generic/synth/cells_map.v
new file mode 100644
index 00000000..a6027534
--- /dev/null
+++ b/generic/synth/cells_map.v
@@ -0,0 +1,10 @@
+module \$lut (A, Y);
+	parameter WIDTH = 0;
+	parameter LUT = 0;
+	input [WIDTH-1:0] A;
+	output Y;
+
+	LUT #(.K(`LUT_K), .INIT(LUT)) _TECHMAP_REPLACE_ (.I(A), .Q(Y));
+endmodule
+
+module  \$_DFF_P_ (input D, C, output Q); DFF  _TECHMAP_REPLACE_ (.D(D), .Q(Q), .CLK(C)); endmodule
diff --git a/generic/synth/prims.v b/generic/synth/prims.v
new file mode 100644
index 00000000..95fcfac7
--- /dev/null
+++ b/generic/synth/prims.v
@@ -0,0 +1,59 @@
+// LUT and DFF are combined to a GENERIC_SLICE
+
+module LUT #(
+	parameter K = 4,
+	parameter [2**K-1:0] INIT = 0,
+) (
+	input [K-1:0] I,
+	output Q
+);
+	assign Q = INIT[I];
+endmodule
+
+module DFF (
+	input CLK, D,
+	output reg Q
+);
+	always @(posedge CLK)
+		Q <= D;
+endmodule
+
+module GENERIC_SLICE #(
+	parameter K = 4,
+	parameter [2**K-1:0] INIT = 0,
+	parameter FF_USED = 1'b0
+) (
+	input CLK,
+	input [K-1:0] I,
+	output Q
+);
+	
+	wire lut_q;
+	LUT #(.K(K), .INIT(INIT)) lut_i(.I(I), .Q(lut_q));
+
+	generate if (FF_USED)
+		DFF dff_i(.CLK(CLK), .D(lut_q), .Q(Q));
+	else
+		assign Q = lut_q; 
+	endgenerate
+endmodule
+
+module GENERIC_IOB #(
+	parameter INPUT_USED = 1'b0,
+	parameter OUTPUT_USED = 1'b0,
+	parameter ENABLE_USED = 1'b0
+) (
+	inout PAD,
+	input I, EN,
+	output O
+);
+	generate if (OUTPUT_USED && ENABLE_USED)
+		assign PAD = EN ? I : 1'bz;
+	else if (OUTPUT_USED)
+		assign PAD = I;
+	endgenerate
+
+	generate if (INPUT_USED)
+		assign O = PAD;
+	endgenerate
+endmodule
\ No newline at end of file
diff --git a/generic/synth/synth_generic.tcl b/generic/synth/synth_generic.tcl
new file mode 100644
index 00000000..e5d88e0d
--- /dev/null
+++ b/generic/synth/synth_generic.tcl
@@ -0,0 +1,24 @@
+# Usage
+# tcl synth_generic.tcl {K} {out.json}
+
+set LUT_K 4
+if {$argc > 0} { set LUT_K [lindex $argv 0] }
+yosys read_verilog -lib [file dirname [file normalize $argv0]]/prims.v
+yosys hierarchy -check
+yosys proc
+yosys flatten
+yosys tribuf -logic
+yosys deminout
+yosys synth -run coarse
+yosys memory_map
+yosys opt -full
+yosys techmap -map +/techmap.v
+yosys opt -fast
+yosys abc -lut $LUT_K -dress
+yosys clean
+yosys techmap -D LUT_K=$LUT_K -map [file dirname [file normalize $argv0]]/cells_map.v
+yosys clean
+yosys hierarchy -check
+yosys stat
+
+if {$argc > 1} { yosys write_json [lindex $argv 1] }