diff --git a/ice40/bitstream.cc b/ice40/bitstream.cc
index a9c46ea8..91f5ede4 100644
--- a/ice40/bitstream.cc
+++ b/ice40/bitstream.cc
@@ -31,7 +31,7 @@ const ConfigEntryPOD &find_config(const TileInfoPOD &tile,
                                   const std::string &name)
 {
     for (int i = 0; i < tile.num_config_entries; i++) {
-        if (std::string(tile.entries[i].name) == name) {
+        if (std::string(tile.entries[i].name.ptr()) == name) {
             return tile.entries[i];
         }
     }
diff --git a/ice40/chip.cc b/ice40/chip.cc
index 277246e5..1c854edf 100644
--- a/ice40/chip.cc
+++ b/ice40/chip.cc
@@ -190,7 +190,7 @@ WireId Chip::getWireBelPin(BelId bel, PortPin pin) const
     assert(bel != BelId());
 
     int num_bel_wires = chip_info.bel_data[bel.index].num_bel_wires;
-    BelWirePOD *bel_wires = chip_info.bel_data[bel.index].bel_wires.ptr();
+    const BelWirePOD *bel_wires = chip_info.bel_data[bel.index].bel_wires.ptr();
 
     for (int i = 0; i < num_bel_wires; i++)
         if (bel_wires[i].port == pin) {
diff --git a/ice40/chip.h b/ice40/chip.h
index fc8b4419..f57f9983 100644
--- a/ice40/chip.h
+++ b/ice40/chip.h
@@ -76,19 +76,23 @@ template <typename T>
 struct RelPtr {
     int offset;
 
-    // RelPtr(T *ptr) : offset(reinterpret_cast<const char*>(ptr) -
-    //                         reinterpret_cast<const char*>(this)) {}
+    // RelPtr(const T *ptr) : offset(reinterpret_cast<const char*>(ptr) -
+    //                               reinterpret_cast<const char*>(this)) {}
 
-    T&operator*() {
-        return *reinterpret_cast<T*>(reinterpret_cast<char*>(this) + offset);
+    const T&operator[](size_t index) const {
+        return reinterpret_cast<const T*>(reinterpret_cast<const char*>(this) + offset)[index];
     }
 
-    T*operator->() {
-        return reinterpret_cast<T*>(reinterpret_cast<char*>(this) + offset);
+    const T&operator*() const {
+        return *reinterpret_cast<const T*>(reinterpret_cast<const char*>(this) + offset);
     }
 
-    T*ptr() {
-        return reinterpret_cast<T*>(reinterpret_cast<char*>(this) + offset);
+    const T*operator->() const {
+        return reinterpret_cast<const T*>(reinterpret_cast<const char*>(this) + offset);
+    }
+
+    const T*ptr() const {
+        return reinterpret_cast<const T*>(reinterpret_cast<const char*>(this) + offset);
     }
 };
 
@@ -165,9 +169,9 @@ struct ConfigBitPOD
 
 struct ConfigEntryPOD
 {
-    const char *name;
-    int num_bits;
-    ConfigBitPOD *bits;
+    RelPtr<char> name;
+    int32_t num_bits;
+    RelPtr<ConfigBitPOD> bits;
 } __attribute__((packed));
 
 struct TileInfoPOD
diff --git a/ice40/chipdb.py b/ice40/chipdb.py
index 4a67d0ba..bb10304b 100644
--- a/ice40/chipdb.py
+++ b/ice40/chipdb.py
@@ -594,10 +594,6 @@ for package in packages:
         bba.u32(pi[1], "bel_index")
     packageinfo.append('{"%s", %d, package_%s_pins}' % (name, len(pins_info), safename))
 
-print("static uint8_t binblob_%s[] = {" % dev_name)
-bba.write_c(sys.stdout)
-print("};")
-
 tilegrid = []
 for y in range(dev_height):
     for x in range(dev_width):
@@ -612,14 +608,30 @@ for t in range(num_tile_types):
     for cb in tile_bits[t]:
         name, bits = cb
         safename = re.sub("[^A-Za-z0-9]", "_", name)
-        bits_list = ["{%d, %d}" % _ for _ in bits]
-        print("static ConfigBitPOD tile%d_%s_bits[%d] = {%s};" % (t, safename, len(bits_list), ", ".join(bits_list)))
-        centries_info.append('{"%s", %d, tile%d_%s_bits}' % (name, len(bits_list), t, safename))
-    print("static ConfigEntryPOD tile%d_config[%d] = {" % (t, len(centries_info)))
-    print("  " + ",\n  ".join(centries_info))
-    print("};")
+        bba.l("tile%d_%s_bits" % (t, safename), "ConfigBitPOD")
+        for row, col in bits:
+            bba.u8(row, "row")
+            bba.u8(col, "col")
+        if len(bits) == 0:
+            bba.u8(0, "dummy")
+        centries_info.append((name, len(bits), t, safename))
+    for name, _, t, safename in centries_info:
+        if ("str_%s" % safename) not in bba.labels:
+            bba.l("str_%s" % safename, "char")
+            bba.s(name, None)
+    bba.l("tile%d_config" % t, "ConfigEntryPOD")
+    for _, num_bits, t, safename in centries_info:
+        bba.r("str_%s" % safename, "name")
+        bba.u32(num_bits, "num_bits")
+        bba.r("tile%d_%s_bits" % (t, safename), "num_bits")
+    if len(centries_info) == 0:
+        bba.u8(0, "dummy")
     tileinfo.append("{%d, %d, %d, tile%d_config}" % (tile_sizes[t][0], tile_sizes[t][1], len(centries_info), t))
 
+print("static uint8_t binblob_%s[] = {" % dev_name)
+bba.write_c(sys.stdout)
+print("};")
+
 switchinfo = []
 switchid = 0
 for switch in switches: