Add configuration option for LoRa Region Code override for region-loc…

…ked builds/variants (#3540)

The main use case for this will be to create a custom Heltec WiFi LoRa 32 V3 SG_923 variant, which will be pre-flashed and sent for regulatory approval for retail sale.

Signed-off-by: Andrew Yong <me@ndoo.sg>
Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

src/configuration.h

@@ -74,6 +74,13 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define RTC_DATA_ATTR
 #endif
 
+// -----------------------------------------------------------------------------
+// Regulatory overrides for producing regional builds
+// -----------------------------------------------------------------------------
+
+// Define if region should override user saved region
+// #define LORA_REGIONCODE meshtastic_Config_LoRaConfig_RegionCode_SG_923
+
 // -----------------------------------------------------------------------------
 // Feature toggles
 // -----------------------------------------------------------------------------

src/mesh/RadioInterface.cpp

@@ -151,10 +151,16 @@ static uint8_t bytes[MAX_RHPACKETLEN];
 void initRegion()
 {
     const RegionInfo *r = regions;
+#ifdef LORA_REGIONCODE
+    for (; r->code != meshtastic_Config_LoRaConfig_RegionCode_UNSET && r->code != LORA_REGIONCODE; r++)
+        ;
+    LOG_INFO("Wanted region %d, regulatory override to %s\n", config.lora.region, r->name);
+#else
     for (; r->code != meshtastic_Config_LoRaConfig_RegionCode_UNSET && r->code != config.lora.region; r++)
         ;
-    myRegion = r;
     LOG_INFO("Wanted region %d, using %s\n", config.lora.region, r->name);
+#endif
+    myRegion = r;
 }
 
 /**