Add --nonet option to host emulator, fix default location for flash.bin (SmingHub#1824)

* Add `--nonet` option to emulator

* Put default host flash.bin in same directory as executable

Author: mikee47

Sming/Arch/Host/Components/hostlib/options.h

@@ -47,7 +47,8 @@
 	   nullptr)                                                                                                        \
 	XX(flashsize, required_argument, "Change default flash size if file doesn't exist", "SIZE",                        \
 	   "Size of flash in bytes (e.g. 512K, 524288, 0x80000)", nullptr)                                                 \
-	XX(initonly, no_argument, "Initialise only, do not start Sming", nullptr, nullptr, nullptr)
+	XX(initonly, no_argument, "Initialise only, do not start Sming", nullptr, nullptr, nullptr)                        \
+	XX(nonet, no_argument, "Skip network initialisation", nullptr, nullptr, nullptr)
 
 enum option_tag_t {
 #define XX(tag, has_arg, desc, argname, arghelp, examples) opt_##tag,

Sming/Arch/Host/Components/hostlib/startup.cpp

@@ -110,13 +110,15 @@ int main(int argc, char* argv[])
 		int pause;
 		int exitpause;
 		bool initonly;
+		bool enable_network;
 		UartServerConfig uart;
 		FlashmemConfig flash;
 		struct lwip_param lwip;
 	} config = {
 		.pause = -1,
 		.exitpause = -1,
 		.initonly = false,
+		.enable_network = true,
 		.uart =
 			{
 				.enableMask = 0,
@@ -187,6 +189,10 @@ int main(int argc, char* argv[])
 			config.initonly = true;
 			break;
 
+		case opt_nonet:
+			config.enable_network = false;
+			break;
+
 		default:;
 		}
 	}
@@ -209,9 +215,14 @@ int main(int argc, char* argv[])
 		sockets_initialise();
 		CUartServer::startup(config.uart);
 
-		bool lwip_initialised = host_lwip_init(&config.lwip);
-		if(lwip_initialised) {
-			host_wifi_lwip_init_complete();
+		bool lwip_initialised = false;
+		if(config.enable_network) {
+			lwip_initialised = host_lwip_init(&config.lwip);
+			if(lwip_initialised) {
+				host_wifi_lwip_init_complete();
+			}
+		} else {
+			hostmsg("Network initialisation skipped as requested");
 		}
 
 		hostmsg("If required, you may start terminal application(s) now");

Sming/Arch/Host/Components/spi_flash/flashmem.cpp

@@ -23,7 +23,8 @@
 
 static int flashFile = -1;
 static size_t flashFileSize = 0x400000U;
-static const char* flashFileName = "flash.bin";
+static char flashFileName[256];
+static const char* defaultFlashFileName = "flash.bin";
 
 #define SPI_FLASH_SEC_SIZE 4096
 
@@ -37,11 +38,14 @@ static const char* flashFileName = "flash.bin";
 
 bool host_flashmem_init(FlashmemConfig& config)
 {
-	if(config.filename != NULL) {
-		flashFileName = config.filename;
+	if(config.filename != nullptr) {
+		strcpy(flashFileName, config.filename);
 	} else {
+		getHostAppDir(flashFileName, sizeof(flashFileName));
+		strcat(flashFileName, defaultFlashFileName);
 		config.filename = flashFileName;
 	}
+
 	flashFile = open(flashFileName, O_CREAT | O_RDWR | O_BINARY, 0644);
 	if(flashFile < 0) {
 		hostmsg("Error opening \"%s\"", flashFileName);

Sming/Arch/Host/README.rst

@@ -152,6 +152,10 @@ See :source:`Sming/Arch/Host/Core/DigitalHooks.h` for further details.
 Network
 ~~~~~~~
 
+.. note::
+
+   Network support is enabled by default. If you don't need it, use the ``--nonet`` option.
+
 Linux
 ^^^^^