gowin: Add the Global Set/Reset primitive

GSR is added automatically if it was not instantiated by the user explicitly.

Compatible with old apicula bases, the functionality does not work, but
the crash does not happen --- just a warning.

Signed-off-by: YRabbit <rabbit@yrabbit.cyou>

1 files changed, 36 insertions, 0 deletions

diff --git a/gowin/pack.cc b/gowin/pack.cc
index c17a20c7..24daee31 100644
--- a/gowin/pack.cc
+++ b/gowin/pack.cc
@@ -660,6 +660,41 @@ static void pack_constants(Context *ctx)
     }
 }
 
+// Pack global set-reset
+static void pack_gsr(Context *ctx)
+{
+    log_info("Packing GSR..\n");
+
+    bool user_gsr = false;
+    for (auto &cell : ctx->cells) {
+        CellInfo *ci = cell.second.get();
+        if (ctx->verbose)
+            log_info("cell '%s' is of type '%s'\n", ctx->nameOf(ci), ci->type.c_str(ctx));
+        if (ci->type == id_GSR) {
+            user_gsr = true;
+            break;
+        }
+    }
+    if (!user_gsr) {
+        // XXX
+        bool have_gsr_bel = false;
+        for (auto bi : ctx->bels) {
+            if (bi.second.type == id_GSR) {
+                have_gsr_bel = true;
+                break;
+            }
+        }
+        if (have_gsr_bel) {
+            // make default GSR
+            std::unique_ptr<CellInfo> gsr_cell = create_generic_cell(ctx, id_GSR, "GSR");
+            gsr_cell->connectPort(id_GSRI, ctx->nets[ctx->id("$PACKER_VCC_NET")].get());
+            ctx->cells[gsr_cell->name] = std::move(gsr_cell);
+        } else {
+            log_info("No GSR in the chip base\n");
+        }
+    }
+}
+
 static bool is_nextpnr_iob(const Context *ctx, CellInfo *cell)
 {
     return cell->type == ctx->id("$nextpnr_ibuf") || cell->type == ctx->id("$nextpnr_obuf") ||
@@ -857,6 +892,7 @@ bool Arch::pack()
     try {
         log_break();
         pack_constants(ctx);
+        pack_gsr(ctx);
         pack_io(ctx);
         pack_diff_io(ctx);
         pack_wideluts(ctx);